Effectiveness of Home-Based, Multi-Trigger,Multicomponent Interventions with an

Environmental Focus forReducing Asthma Morbidity

A Community Guide Systematic ReviewDeidre D. Crocker, MD, Stella Kinyota, MD, MPH, Gema G. Dumitru, MD, MPH,

Colin B. Ligon, MD, Elizabeth J. Herman, MD, MPH, Jill M. Ferdinands, PhD,David P. Hopkins, MD, MPH, Briana M. Lawrence, MPH, Theresa A. Sipe, PhD, MPH,

Task Force on Community Preventive Services

Context: Asthma exacerbations are commonly triggered by exposure to allergens and irritants withinthehome.Thepurposeof this reviewwas toevaluate evidence that interventions that target reducing thesetriggers through home visitsmay be benefıcial in improving asthmaoutcomes. The interventions involvehome visits by trained personnel to conduct two ormore components that address asthma triggers in thehome. Intervention components focus on reducing exposures to a range of asthma triggers (allergens andirritants) through environmental assessment, education, and remediation.

Evidence acquisition: Using methods previously developed for the Guide to CommunityPreventive Services, a systematic review was conducted to evaluate the evidence on effectivenessof home-based, multi-trigger, multicomponent interventions with an environmental focus toimprove asthma-related morbidity outcomes. The literature search identifıed over 10,800 cita-tions. Of these, 23 studies met intervention and quality criteria for inclusion in the fınal analysis.

Evidence synthesis: In the 20 studies targeting children and adolescents, the number of days withasthma symptoms (symptom-days) was reduced by 0.8 days per 2 weeks, which is equivalent to 21.0symptom-days per year (range of values: reduction of 0.6 to 2.3 days per year); school days missedwere reduced by 12.3 days per year (range of values: reduction of 3.4 to 31.2 days per year); and thenumber of asthma acute care visits were reduced by 0.57 visits per year (interquartile interval:reduction of 0.33 to 1.71 visits per year). Only three studies reported outcomes among adults withasthma, fınding inconsistent results.

Conclusions: Home-based, multi-trigger, multicomponent interventions with an environmentalfocus are effective in improving overall quality of life and productivity in children and adolescentswith asthma. The effectiveness of these interventions in adults is inconclusive due to the smallnumber of studies and inconsistent results. Additional studies are needed to (1) evaluate theeffectiveness of these interventions in adults and (2) determine the individual contributions of thevarious intervention components.(Am J Prev Med 2011;41(2S1):S5–S32) Published by Elsevier Inc. on behalf of American Journal of PreventiveMedicine

From the Air Pollution and Respiratory Health Branch, Division ofEnvironmental Hazards and Health Effects, National Center for Envi-ronmental Health (Crocker, Kinyota, Dumitru, Ligon, Herman), theCommunity Guide Branch, the Epidemiology and Analysis ProgramOffıce, the Offıce of Surveillance, Epidemiology and Laboratory Ser-vices (Hopkins, Lawrence, Sipe), the Influenza Division, National Cen-ter for Immunization and Respiratory Diseases (Ferdinands), CDC,Atlanta, Georgia

Author affıliation is shown for the time research was conducted.

The names and affıliations of the Task Force members are listed at thefront of this supplement and at www.thecommunityguide.org/about/task-force-members.html.

Address correspondence to: Gema Dumitru, MD, MPH, CommunityGuide Branch, Epidemiology and Analysis Program Offıce, the Offıce ofSurveillance, Epidemiology and Laboratory Services, CDC, 1600 CliftonRoad, MS E-69, Atlanta GA 30333. E-mail: ggd7@cdc.gov.

0749-3797/$17.00doi: 10.1016/j.amepre.2011.05.012

Published by Elsevier Inc. on behalf of American Journal of Preventive Medicine Am J Prev Med 2011;41(2S1):S5–S32 S5

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Context

Asthma is a common chronic respiratory diseaseand a major source of morbidity in the U.S. Itaffects more than 20million Americans and can

ubstantially reduce quality of life, and its prevalence hasore than doubled since 1980.1 Asthma is also a major

cause of hospital use, resulting in approximately 500,000hospitalizations, 1.8 million emergency department vis-its, and 12.3 million physician offıce visits annually.1

Asthma further results in very high direct and indirectcosts, with over $32.7 billion in healthcare costs spentannually when adjusted to 2007 U.S. dollars.2 In 2001asthma was ranked the 25th leading cause of disability-adjusted life-years (DALYs) lost worldwide, with an esti-mated 15 million DALYs lost.3 Finally, asthma is a lead-ng cause of school absences for U.S. children, with anstimated 12.8 million school days missed for the year003.4

Relationship Between the Home Environmentand AsthmaThe home environment is inextricably linked with thehealth of its occupants. This is especially true for diseasessuch as asthma. Numerous studies confırm that sensiti-zation among genetically susceptible populations to cer-tain indoor allergens such as house dust mite, animaldander, and cockroach is a risk for developing asthma inchildren.5–11 Studies have shown that poor housing qual-ity is strongly associated with poor asthma control evenafter controlling for potentially confounding factors suchas income, smoking, overcrowding, and unemploy-ment.12 To treat asthma properly, conditions in the homeenvironment must be addressed.13–15

Exposure to allergens and irritants within the homeenvironment can trigger or exacerbate episodes ofasthma.5,6Moisture from leaky plumbing, high humidity,nd cracks in floors and walls can contribute to moldrowth; provide water for cockroaches, mice, and dustites; and provide avenues through which cockroachesnd mice can enter the home.

Common Asthma Triggers and Strategies toReduce TriggersThe most common asthma triggers within the home in-clude allergens from house dust mites, pets, cockroaches,rodents, and mold as well as irritants such as environ-mental tobacco smoke (ETS) and indoor air pollutants.6,7

Reducing these asthma triggers in the home can be ac-complished throughmultiple strategies, such as environ-mental remediation to fıx physical problems within thehome and environmental education to address behaviors

such as smoking and failing to seal food. Briefly, the s

existing evidence for individual strategies to reduce themost common asthma triggers is as follows:

Dust mites. The house dust mite is one of the mostcommonly implicated asthma triggers.10,11,16,17 The linkbetween house dust mites and asthma symptoms hasbeen well established. Numerous well-designed studieshave demonstrated that asthma symptoms, pulmonaryfunction, and need for medication in dust mite–sensitiveasthma patients correlate with the level of exposure tohouse dust mite.9–11,16,17 There is conflicting evidence aso whether reducing exposure to house dust mite alonean improve asthma symptoms and reduce medicationsage.18–20 This asthma trigger can be removed by usingllergen-impermeable pillow and mattress covers, wash-ng bedding in hot water �130°F, removing old carpet,educing home humidity to �60%, and washing stuffednimals weekly.8,14,21,22

Pets. Pet allergens, particularly dog and cat, are well-recognized asthma triggers in sensitized individuals.23–25

A prospective controlled study of 554 HMO memberswith asthma found those with a dog in the home whowere sensitized to dog allergen had a 49% increase in therisk of needing acute asthma care each year even afteradjusting for other risk factors.26 Removing pets from thehome is the most effective method to reduce exposure topet dander in sensitized patients.27 Alternately, keepingpets out of bedrooms can reduce airborne pet danderallergen levels fıvefold.28

Cockroaches. Cockroach allergen is a common causeof asthma exacerbations in urban environments. In theNational Cooperative Inner-City Asthma Study (NCI-CAS), children sensitized and exposed to high levels ofcockroach allergen showed increasing asthma severity asthe level of cockroach allergen exposure increased.29 Al-though hard to eliminate, cockroach allergen can be re-duced using “integrated pest management” strategies.These include teaching residents to remove food andwater sources, clean surfaces and floors, seal trash con-tainers, store food carefully, use gel baits to exterminateroaches, and seal cracks and small holes in the residenceto keep roaches out.30

Mice and rats. Mouse and rat allergen exposure is com-mon in inner-city homes. In the NCICAS study, 95% ofthe 608 homes tested had detectable mouse allergen in atleast one room of the home, with highest levels in thekitchen.31 However, the link between mouse allergen ex-osure and asthma symptoms is not as clear.32 Integratedest management techniques can also help reducemousend rat allergen. These include fılling holes, vacuuming,leaning, using low-toxicity pesticide, placing traps, and

toring food carefully.33

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Mold. There is a strong link between asthma and mold.The IOM’s “Report on Damp Indoor Spaces” found suf-fıcient evidence of an association between mold andasthma symptoms in sensitized individuals.34 A subse-uent analysis estimated that exposure to dampness andold account for 21% of current asthma in the U.S.35

Mold-sensitive people can be protected by removingmold from hard, nonporous surfaces; discarding mold-contaminated materials (e.g., carpet, ceiling tiles); andaddressing the source(s) ofmoisture responsible formoldgrowth.34

Environmental tobacco smoke. Environmental to-bacco smoke (ETS) has been linked to increased risk ofdeveloping asthma36,37 as well as increased severity andrequency of exacerbations in children with asthma.38,39

Interventions to reduce ETS exposure focus on counsel-ing/treatments to encourage smoking cessation, and air-fıltration methods to reduce the presence of tobaccosmoke in the air.13 Smoking-cessation interventions di-rected toward parents of children with asthma haveshown some success in reducing parental smoking andreducing the number of cigarettes smoked in thehome.40,41

Current asthma guidelines emphasize smoking-cessation counseling as part of treatment for smokerswith asthma, or smokers with children who haveasthma.14 Complete smoking bans in the home have beenshown to have a small but noteworthy reduction in ETSexposure in caregivers who are unwilling to stop smok-ing.42,43 Although studies have found that air fılters andentilation can reduce the indoor concentration of ETSarticles in the air,44 overall there is little research on the

effıcacy of air fılters and ventilation in improving asthmaoutcomes.13

Indoor pollutants. Although often a trigger for asthmaexacerbations, indoor pollutants are rarely the focus ofhome environmental interventions. Such pollutants in-clude, but are not limited to nitrogen dioxide, particulatematter (resulting from biomass combustion products),and bacterial endotoxins.45–47 Use of gas stoves andood-burning appliances or fıreplaces have been associ-ted with increased wheezing in schoolchildren andsthma exacerbations.48,49 However, data from a recentmeta-analysis did not fınd any association between theuse of solid biomass fuels and asthma in children orwomen.50

More comprehensive lists of indoor asthma triggersand recommendations to remove asthma triggers fromthe indoor environment are provided in the 2007 Na-tional Asthma Education and Prevention Program Ex-pert Panel Report 3, Section 314 at www.nhlbi.nih.gov/

guidelines/asthma/06_sec3_comp3.pdf (pdf p. 24, Figure h

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3-20) , and the Environmental Protection Agency (EPA)list of publications and resources.44,51,52

In summary, a variety of triggers in the home canworsen asthma symptoms. Although several studies doc-ument effectiveness of interventions aimed at singleasthma triggers in reducing allergen levels,33,53,54 otherecent studies suggest that single-component interven-ions or those that address a single asthma triggermaynote as effective as interventions that address multiple trig-ers using multiple intervention components.14,55,56

Focus for This ReviewFor several reasons, the systematic review develop-ment team (see Methods), with the approval of theTask Force on Community Preventive Services (TaskForce), decided to evaluate the effectiveness of home-based environmental interventions for improvingasthma morbidity outcomes. The main research ques-tion was, “Do multi-trigger, multicomponent, home-based environmental interventions improve asthmamorbidity?”First, this review focused on approaches addressing

multiple asthma triggers, which are more likely to beeffective at a population level because more than half ofindividuals with asthma are sensitive to multiple aller-gens.57–59 Second, there is evidence that using multipleapproaches to address environmental triggers, specifı-cally approaches that use both education and remedia-tion, could be more effective than interventions that useeither alone.60,61 Third, because of limitations in trans-ortation,money, and time, traditional asthma educationrograms set in clinic or school settings often have diffı-ulty attracting and retaining participants.62

This review focused on environmental interventionsconducted primarily in the home setting, which mayaddress many of the limitations found in other settings.In these interventions, home visitors educate participantsin a familiar setting that requires no travel or time awayfrom work, which may increase participation and re-tention. In addition, after visually assessing home en-vironmental conditions, a trained home visitor canprovide a more accurate assessment of asthma triggersin the home than could a survey completed by homeresidents and administered in a clinic setting. Ideallyand most importantly, home visitors attempt to buildtrusting relationships with clients, thereby enhancingthe visitors’ effectiveness in motivating behavioralchanges.62 These qualities suggest that home-basednvironmental interventions for asthma are distinctrom andmay be more effective than traditional clinic-ased asthma programs.Although environmental interventions for asthma

ave been evaluated in several publications, there has

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been no recent systematic review of the literature thatfocuses primarily on home-based environmental inter-ventions for children and adults with asthma.Most of theliterature on home-based, multi-trigger, multicompo-nent interventions with an environmental focus has beenpublished in the last 4 years. Therefore, a comprehensive,up-to-date systematic review was needed to compile andsummarize the evidence on effectiveness of these inter-ventions in improving asthma morbidity.

Clinical Basis for This ReviewThe National Asthma Education and Prevention Pro-gram (NAEPP) Expert Panel Report 3, “Guidelines forthe Diagnosis and Management of Asthma,”14 forms theclinical basis for this systematic review. This report,the most widely used clinical practice guidelines forasthma in theU.S., outlines evidence-based guidelines forthe treatment of asthma, including pharmaceutic man-agement, educational activities, and environmental con-trols. This review examines interventions highlighted inthe NAEPP guidelines that have been found to be effec-tive in clinical practice at a population level.

Intervention DescriptionTo be considered for inclusion in this review of home-based, multi-trigger, and multicomponent interventionswith an environmental component (hereafter referred toas “home-based environmental interventions”), inter-ventions had to: include at least one home visit; targetmore than one asthma trigger; and includemore than oneintervention component, at least one of which is an envi-ronmental component. Other accepted standard prac-tices for asthma treatment identifıed in several of theincluded studies (e.g., general asthma education, self-management education, social services, or coordinatedcare) were not required components of the intervention.The intervention characteristics and components, alongwith defınitions for each, are listed in Table 1.

Composition of Multi-Trigger,Multicomponent, Home-BasedEnvironmental InterventionsHome-based environmental interventions can vary con-siderably in cost, time, and effort. Some interventionsprovide more intense environmental remediation andhave a smaller education component, whereas other in-terventionsmay provide less remediation and focusmoreon environmental and self-management education.In the asthma fıeld, the term “remediation” has typi-

cally been used to indicate structural changes in the hometo reduce environmental triggers; in contrast, a variety ofterms has been used to describe nonstructural changes.

For the purposes of this review, any changes in the

home—structural or nonstructural—designed to reduceasthma triggers were defıned as remediation. Nonstruc-tural changes to the home were classifıed as either minorormoderate remediation. Providing low-cost items, suchas an allergen-impermeable cover, to reduce asthma trig-gers constituted minor remediation. The active involve-ment of a home visitor and the provision ofmultiple low-

Table 1. Intervention characteristics and components ofhome-based, multi-trigger, multicomponent interventionswith an environmental focus to reduce asthmamorbiditya

Interventioncharacteristics Definition

Home visit Some effort to change the homeenvironment

AssessRemediateEducate

Conducted by someone with training orexperience

Community health workersPest control professionalsClinicians or healthcare providers

Multi-trigger Activities that reduce exposure to two ormore environmental triggers thatexacerbate asthma

Multicomponent More than one of the seven identifiedintervention components, includingat least one component directedtoward home environment

Interventioncomponents

Environmentalassessment

In-home written assessment ofenvironmental triggers

Environmentalremediation

Actions conducted or financed to reducetriggers in the home

Environmentaleducation

Patient education regarding actions toreduce triggers in the home

Self-managementeducation

Patient education on monitoringsymptoms and taking action tomodify treatment

Asthmaeducation

General education on asthma without aself-management educationcomponent

Social services Services to improve access to medicalcare or to advocate forenvironmental remediation

Coordinatedcare

Services to improve coordination of carebetween healthcare providers andhome health workers

aAt least one environmental component is necessary for each ofthese interventions. The three environmental components are envi-ronmental assessment (EA), and environmental remediation (ER),and environmental education (EE).

or moderate-cost materials to reduce triggers, such as in

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integrated pest management constitutedmoderate reme-diation. Any substantial structural changes to the homeconstitutedmajor remediation. (Full defınitions ofmajor,moderate, and minor environmental remediation areprovided in Appendix A.)Education efforts varied in type and intensity. Some

education-oriented interventions focused primarily oneducation to reduce environmental triggers (environ-mental education), whereas others placedmore emphasison asthma self-management education. The educationcomponent could also vary in intensity depending on thenumber of home visits, the amount and breadth of edu-cation given at each home visit, and the training of thehome visitor. Some interventions used multiple detailedmodules over several home visits to teach clients trigger-reduction and asthma-management behaviors, whereasother interventions provided less-detailed education overone or two home visits. The home visitors could be med-ical professionals, such as physicians, nurses, social work-ers, and respiratory therapists, or people from within thecommunity where the interventionwas conducted (com-munity health workers [CHWs]). Most of the CHWswere notmedical professionals but were given specializedtraining to conduct home environmental assessmentsand to provide environmental and self-managementeducation.One of the challenges of characterizing home-based

environmental interventions is that various terminol-ogies are used in the literature to describe the aspects ofthis intervention here termed “multi-trigger” and“multicomponent.” These aspects are most oftenlumped under the terms “multifaceted” or “compre-hensive,” which are often not specifıcally defıned.14,57

The term “multifaceted” has been used to describeinterventions directed toward more than one asthmatrigger or interventions with more than one compo-nent. In this review, to highlight the importance ofconsidering both multiple triggers and components,the choice was made to use the more-specifıc terms“multi-trigger” and “multicomponent.” For additionalinformation about terms and defınitions used in thisarticle, please refer to the Glossary (Appendix A).

Evidence AcquisitionThe general methods used to conduct systematic reviewsfor the Community Guide are described in detail else-where.63,64 The methods for conducting this specifıc re-view, including forming a systematic reviewdevelopmentteam (review team), creating a conceptual approach, de-veloping a search strategy, selecting intervention criteria,

conducting abstraction and evaluation of studies,making

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outcome determinations, and defıning the interventionare presented below.

The Systematic Review Development TeamThe review team included three subgroups:

● the coordination team, which drafted the analyticframework for reviews; managed the data collectionand review process; and drafted evidence tables, sum-maries of evidence, and reports;

● the consultation team, which reviewed and com-mented on materials developed by the coordinationteam and set priorities for this review;

● the abstraction team, which collected and recordeddata from studies for possible inclusion in the system-atic review.The names and affıliations of team members are pre-

sented in Appendix B.

Conceptual ApproachThe analytic framework (Figure 1) shows the conceptualapproach that guided the review process. This fıgure por-trays the relationships among people with asthma, theirhouseholds, and conditions in the physical environment,and shows the pathways along which an intervention ishypothesized to work to improve asthma outcomes. Theframework indicates that home-based, multi-trigger,multicomponent interventions with an environmentalfocus are thought to reduce asthma morbidity throughtwo different but intersecting pathways. One pathwayruns through environmental assessment and remedia-tion to change the physical environment (in this case thehome). The second pathway runs through education in-tended to change behavior of people with asthma andtheir household members.Along the environmental pathway, interventions that

incorporate environmental assessment and remediationtarget characteristics of the physical environment andlead to reduced levels of asthma triggers in the home.Along the education pathway, interventions that incor-porate environmental education, self-management edu-cation, or general asthma education, target all membersof the household.These efforts are intended to improve asthma

knowledge, attitudes, and skills of household mem-bers, which should translate into improved asthmamanagement behaviors. These asthma-managementbehaviors (AMBs) include more frequent use ofasthma controller medications, better recognition ofasthma symptoms, and use of peak flow meters.14

AMBs could also include reducing asthma triggers byusing integrated pest management to decrease both the

number of insect and rodent pests65 and by washing

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bedding in hot water to reduce dust mites. As depictedin Figure 1, the education pathway feeds back into theenvironmental pathway by educating about behaviorsto reduce asthma triggers (trigger-reduction behaviorsor TRBs).Both of these pathways are thought to result in im-

proved asthma control, asmeasured by outcomes includ-ing reduced use of rescue medications and reducedasthma exacerbations.14 Improved asthma control haseen shown ultimately to result in improvements inownstream outcomes of asthma morbidity such as de-reased healthcare use (fewer hospitalizations, emer-ency department visits, and unscheduled offıce visits),mprovedproductivity (fewer school orwork daysmissednd improved academic performance or work productiv-ty), improved quality of life (fewer symptom-days, fewerctivity limitations, and improved quality-of-life [QOL]cores), and improved physiologic measures (better pul-onary function test scores and changes in immune

Figure 1. Analytic framework that guided the systematic rED, emergency department; ETS, environmental tobacco smoke; Qo

esponse).

Search for Evidence

Study inclusion criteria. To be included in this review,a study had to meet the following criteria: (1) representprimary research published in a peer-reviewed journal,technical report, or government report, or unpublishedresearch between January 1966 and February 2008; (2)meet Community Guideminimum research quality stan-dards for study design and execution; (3) evaluate inter-ventions with at least one home visit; (4) focus on reduc-ing multiple environmental asthma triggers in the home;(5) include more than one intervention component; and(6) evaluate at least one health outcome. Studies thatevaluated primary prevention of asthma or occupationalasthma were excluded because those topics were beyondthe scope of this review.

Search strategy. The literature search consisted of asystematic search of multiple databases, reviews of bibli-ographic reference lists, and consultationswith experts in

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the fıeld who were part of the review team (Appendix B).

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The following electronic databases were searched:MEDLINE, EMBASE, ERIC, PsycINFO,Web of Science,Cochrane Library, Sociological Abstracts, and CINAHL.Only English language articles were included in thesearch. The initial literature search on the topic was con-ducted in July 2007, and a second search was conductedin February 2008.

Abstraction and Evaluation of StudiesEach study that met the inclusion criteria was evaluatedfor suitability of study design and study execution by twoindependent abstractors using the standardizedCommu-nity Guide abstraction form.63 Differences in ratings be-tween the abstractors were resolved by consensus of theentire abstraction team. The suitability of each study de-sign was rated as “greatest,” “moderate,” or “least,” de-pending on the degree to which the design protectedagainst threats to validity. The execution of each studywas rated as “good,” “fair,” or “limited,” based on severalpredetermined factors that could potentially limit astudy’s utility for assessing effectiveness. Only those stud-ies in which quality of execution was rated as “good” or“fair” were included in the review. From the data in thoseincluded (or qualifying) studies, the team calculated ef-fect sizes for study outcomes whenever suffıcient infor-mation was available to do so. The team considered non-qualifying studies as sources of relevant backgroundinformation to help conceptualize the review and to pro-vide information on potential barriers to implementationand other benefıts or harms. The nonqualifying studies,however, were not included in analyses.

Outcomes evaluated: primary outcomes. The pri-mary outcomes evaluated in this review were quality oflife (symptom-days, QOL scores); healthcare utilization(hospitalizations, emergency department visits, and un-scheduled offıce visits); productivity (school orwork daysmissed); and physiologic outcomes (changes in pulmo-nary function). All primary outcomes were analyzed forthe client with asthma. The studies in this review mea-sured these outcomes using a variety of effect measuresfor each outcome category. The team attempted toconsolidate and compare outcomes when appropriate.The outcome categories and associated effect measuresfor each outcome are listed in Table 2.

Outcomes evaluated: additional outcomes. Besidesthe four primary outcomes noted above, many studiesreported additional important outcomes, such as changesin indicators of asthma triggers (e.g., allergen levels, coti-nine levels), behaviors to manage asthma (e.g., asthmaself-management skills, use of preventive medication),TRBs (e.g., washing bedding, sealing food), and asthma

control (e.g., reducing the number of asthma exacerba-

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tions, needing less rescue medication). Most of these ad-ditional outcomes listed above were reported using het-erogeneous measures, which were not comparable;therefore, the effectiveness was reported by summarizingthe number of studies in which intervention groupsshowed improvement compared to baseline and to thecomparison group. The one exception is ETS exposure,which had enough comparable measures to allow quan-titative summary.

Summary Effect EstimatesCommunity Guide systematic reviews consider data fromall available studies of suffıcient quality that compareoutcomes in a group exposed to an intervention withoutcomes in a group either concurrently or historicallyunexposed (or less exposed) to the intervention.63,64

Consistent with the practices of many groups that focuson population-based or public health interventions,66

this approach is broadly inclusive of a range of studydesigns. Studies with least-suitable study designs wereincluded in the current analyses because they did provideuseful information. The team recognized, however, thatstudies of least suitable study design could overestimateeffects because of the lack of a comparison group, sodifferences in study design were considered when inter-preting results across the body of evidence. A more de-tailed explanation of themethods used for this systematicreview is presented in Appendix C.The outcomes of interest in each study were generally

ascertained from record reviews, client self-reports, orobjective measures. Self-report data included dichoto-mous reports over a given time period or Likert-scalemeasures that reflected the frequency of the outcome.Intervention effectiveness was evaluated by assessingbefore–after changes in relevant outcomes in the inter-vention group and adjusting for concurrent changes inthe comparison group when one was available. To facili-tate comparison across studies, estimated interventioneffects were expressed in common units that were appro-priate to each outcome of interest.63,64 Effect estimatesfor continuous data (e.g., symptom-free days, hospitalvisits) were expressed either as groupmean differences orrelative percentage changes (%), and those for dichoto-mous data (e.g., proportion of children with asthmasymptoms) were expressed as absolute percentage pointchanges. Medians with interquartile intervals (IQI) wereused as summary effectmeasures except when the samplesize was less than 7 studies, inwhich case a range of valueswas provided. Studies with results that could not be con-verted to mean differences, percentage point changes, orrelative percentage changes could not be included in the

summary effect measures. These results were reported

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separately, however, to reflect the complete evidence baseand to assess consistency across all studies.

Evidence SynthesisThe search identifıed 32 studies or study arms (here-after collectively referred to as “studies”)30,57,67–96

evaluating the effectiveness of home-based, multi-trigger, multicomponent interventions. Twenty-threestudies57,68–72,74,75,78–82,85–94 met the quality criteriafor inclusion in this review. The other nine studieswere excluded due to limited quality of execution.Details of the 23 qualifying studies are provided on theCommunity Guide website at www.thecommunityguide.org/asthma/supportingmaterials/SET_multicomponent.pdf.Appendix D provides a summary of the characteristics ofeach study evaluated. Twenty-nine papers12,97–124 pro-

Table 2. Systematic review outcomes and associated me

Outcome of interest Outcome categories

Quality of life Symptom-days

Quality-of-life or symptom score

Healthcare utilization Hospitalizations (H)

Emergency department visits (ED)

Unscheduled office visits (UO)

Combined acute care visits

Productivity School days missed

Physiologic outcomes FEV1, FVC, FEV1/FVC, VC

Asthma triggerindicators

Allergen levels, cotinine levels

Asthma-managementbehaviors

Use of controller medications, use ofasthma action plans

TRBs Washing sheets in hot water, eliminatinor reducing smoking behaviors, use ointegrated pest managementstrategies

Asthma control Asthma exacerbations, use of rescuemedications, use of oralcorticosteroids

FEV1, forced expiratory volume in 1 second; FVC, forced vital capac

ided additional information on the qualifying studies. T

Study and Intervention CharacteristicsThe 23 qualifying studies that evaluated the home-based,multi-trigger, multicomponent interventions used a va-riety of research designs, of varying quality of execution(Table 3).The number of participants in the studies ranged from

18 to 1033, with a median number of 104 participants(interquartile interval [IQI]: 64–274). Follow-up periodsranged from 1 month to 48 months, with a medianfollow-up period of 12 months (IQI: 12–18 months).Attrition (drop-out) rates were obtained for 21 of the 23studies57,68–72,75,78–82,85–88,90–94 and ranged from 0% to78% at the follow-up time used for the current analysis(6–15 months). The study85 with a 78% attrition rate is aeast-suitability study and stated that the high attritionas due primarily to participants moving from the area.

es

Effect measure

ean difference in number of symptom-days/yearbsolute percentage change in children with �1 symptom-dayper time period

elative percentage change in quality-of-life or symptom score

ean difference in number of visits

ean difference in number of visits

ean difference in number of visits

ean difference in number of visits combined (H � ED � UO)ercentage of participants with �1 visit

ean number of daysercentage of children with �1 school day missed per year

predicted FEV1 or FEV 0.5iters/minute FEV1 or FEV 0.5predicted peak flow

iters/minute peak flow

ercentage change trigger levelean change in trigger concentration

ercentage change in participants using controllermedications

ercentage change in participants using controllermedications dailyean number of days of controller useean dose of controller medication

ercentage change in people conducting TRBsbsolute number of people conducting TRBsR of conducting more TRBs

ercentage change in asthma exacerbationsbsolute number of asthma exacerbationsean amount of controller medicationbsolute number of oral corticosteroid regimensean British Thoracic Society step scoreercentage of participants in asthma severity categories

RB, trigger-reduction behavior; VC, vital capacity

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28%) for the 21 studies. Twelve studies57,68–70,75,78,80,81,86,88,91,109

provided information on attrition rates for both interven-tion and comparison groups. The intervention group hada median attrition rate of 16% (IQI: 7%–19.8%), and thecomparison group had an attrition rate of 14% (IQI:9%–24%).The content and components of the intervention var-

ied considerably among the studies reviewed, and arelisted in detail in Appendix D. In summary, 21 of the 23tudies (91%) conducted an environmental assessment;f these, 17 (74%) also included environmental remedia-ion activities (minor [three studies; 18%], moderate [tentudies; 59%], or major [four studies; 23%]). Another1 studies (91%) also included some form of educationsix studies [29%] included education without remedia-ion). Education focus ranged from primarily environ-ental education to primarily asthma self-managementducation, including monitoring asthma symptoms andhe use of asthma management plans.Most studies focused equally on both environmental

nd self-management education. Two studies (9%) fo-used only on remediation and did not have an educa-ional component. Of the 23 studies, 14 were tailoredased on exposure to asthma triggers in the home; ofhese, seven also included specifıc allergen sensitivities inailoring the intervention. Number of home visits wasne (three studies), two to seven (15 studies), and eight orore than eight (fıve studies). In the 23 studies, homeisits were made exclusively by CHWs (six studies),urses (fıve studies), respiratory therapists (two studies),hysicians (two studies), social workers (one study),ousing offıcers (one study), environmental educators

Table 3. Design and quality of studies included in systeminterventions to reduce asthma morbidity

Quality of execution

Suitability o

Greatest; n � 14

Good (0–1limitations)

Individual RCTMorgan 200457

Fair (2–4 limitations) Group RCTBarton 200768

Individual RCTsBrown 2006,69 Carter 2001,70

Eggleston 2005,71 Evans 1999Hughes 1991,75 Kercsmar2006,78 Klinnert 2005,79 Krieg2005,80 Krieger 2008,81 Parke2007,88 Smith 200591

Before-and-after, concurrentcomparison groupNishioka 200686

Limited (�5limitations)

—

one study), and trained sanitarians (one study). In four p

ugust 2011

of the studies, mixed teams of CHWs and nurses (twostudies), social worker, nurse, and respiratory therapist(one study), and research assistant and pest control pro-fessional (one study) conducted the home visits. In 22 ofthe studies, information on asthma severity was included,and the results are indicated inAppendixD. Finally, 20 ofthe studies evaluated interventions targeting homes inwhich only children or adolescents had asthma; one studyexclusively targeted adults; and two studies targeted chil-dren and adults (results of these last two studies wereincluded both in the child and adult analyses).

Outcomes in Children and Adolescents

Outcomes related to quality of life. Sixteen stud-ies57,68,71,72,74,78–82,85,87–89,92,94 measured changes inquality of life among children or adolescents with asthma.These studies showed overall improvements in the numberof asthma symptom-days, the proportion of children oradolescents with asthma symptoms, and in scores fromsymptom or QOL surveys. Six studies57,72,78,80,81,94 evalu-ted changes in the number of symptom-days and showedn overall median reduction of 0.8 symptom-days/2-weekeriod (range of values: 0.6 to 2.3 symptom-days/2-weekseduction)or21.0 fewer symptom-days/year (Figure2).Theedian reduction in symptom-days/2-week period was 0.7ymptom-days in the subset of controlled trials and 2.3ymptom-days in the subset of uncontrolled studies.Four studies71,82,85,109 evaluated changes in the pro-ortion of children or adolescentswith any asthma symp-oms on follow-up and found a median absolute reduc-ion of 15.4 percentage points (range of values: 1.7

review of home-based, multi-trigger, multicomponent

dy design; N � 23 qualifying studies

Moderate Least; n � 9

— —

— Before-and-after, no concurrentcomparisonLevy 2006,82 Nicholas 2005,85

Primomo 2006,89 Shelledy 2005,90

Somerville 2000,92 Stout 1998,93

Thyne 2006,94 Hasan 2003,74

Oatman 200787

— —

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crease). There was amedian absolute re-duction of 5.2 per-centage points in theproportion of partici-pants with asthmasymptoms in the sub-set of controlled trialsand a 27.4 percentagepoint median absolutereduction in the pro-portion of partici-pants with asthmasymptoms for uncon-trolled trials (Figure3).There was a median

relative improvementof 16.5% (IQI: 1.8% to25% improvement) insymptom or QOLscores from the ninestudies68,71,79–82,87,89,92 that measured this outcome. Theimprovement in QOL scores was much smaller in thesubset of controlled trials (3%) than in the subset ofuncontrolled studies (25%) (Figure 4).An examination was alsomade of the subset of studies that

specifıcally used the Juniper Quality of Life Score (six studies:fourcontrolled trials andtwouncontrolled trials) tohelpdeter-mine clinical signifıcance of improvements in quality of life.TheJuniperQualityofLife(QOL)scoreisavalidatedquestion-naire that measures symp-toms, activity limitation,andemotional functionona7-point scale and has beenshowntocorrelatewithclin-ical symptoms.125 An in-rease of 0.5 pts or more isonsidered clinically signifı-ant. The overall medianmprovement in the JuniperOL score using all of thetudies was 0.4 pts (range ofalues: 0.02 pts to 1.41 pts),hich is not consideredlinically signifıcant. Theedianimprovement intheontrolled studies was 0.13ts (range of values: 0.02 ptso0.6pts) and1.1pts (rangef values: 0.8 pts to 1.41 pts)n the uncontrolled studies

Figure 2. Quality of life: meaNote: Gray box represents interquabe calculated.

Figure 3. Quality of life: peNote: Gray box represents intercould be calculated.

Figure 5). pct pts, percentage points

Several studies measured QOL outcomes using mea-ures different from those reported above and werehus analyzed separately. One study88 measured indi-vidual instead of combined symptom scores and foundimprovement in two of six scores. Several studies mea-sured quality of life using days of limitation on activity,with inconsistent results. One study74 found a reduc-ion of 22.0 percentage points in the proportion ofhildren or adolescents with 8 or more days in whichctivity was limited per year (p�0.001). Another

mptom-daysnterval or range; CIs were added to graph if reported in study or could

tage of children with symptom-daysile interval or range; CIs were added to graph if reported in study or

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study71 found a reduction of 7.7 percentage points inhe proportion of children with 1 or more days ofctivity limitation between the intervention and con-rol group, which was not signifıcant.A study by Krieger et al. in 200580 found a signifıcant

reduction in the number of days with activity limitationbetween the intervention and the control group. A laterstudy by the same author81 found a signifıcant reductionn days of activity limitation frombaseline in the interven-

Figure 4. Quality of life: relative % change in symptom/quNote: Gray box represents IQI or range; CIs were added to graph if repIQI, interquartile interval

Figure 5. Quality of life: Juniper quality-of-life scoreNote: Gray box represents interquartile interval or range; CIs were adcould be calculated.

pct pts, percentage points; pts, points

ugust 2011

tiongroupbutnotbetweenthe intervention and thecontrol group. Anotherstudy57 reported a signifı-cant reduction in thenum-ber of days when the childhad to slow down or stopplay because of asthma inthe intervention groupcompared to the controlgroup, whereas a laterstudy85 found no improve-ment for this outcome. An-other study82 found a re-duction of 38.0 percentagepoints in the proportion ofchildren who had to slowdown or stop activities be-cause of asthma.

Outcomes related toproductivity. Ten studies57,69,74,75,80,81,85,87,90,92 mea-sured productivity outcomes in children or adolescentsand showed a decrease in the number of school daysmissed. Six studies74,75,80,81,85, 92 specifıcally mentionedhat school days missed were due to asthma. Four stud-es57,69 ,87,90 didnot saywhether school daysmissedweredueoasthmaorothercauses.Fivestudies57,75,87,90,92measuredthemean number of school daysmissed (Figure 6) and showed amedianabsolutereductionof12.3schooldaysmissedper year

(range of values: 3.4 to31.2 reduction in schooldays missed). The me-dian absolute reductionin school days missed was6.5 days for controlled trialsversus 18.2 days for un-controlled trials. Threestudies80,81,85 measuredchanges in the proportionof children or adolescentswho missed 1 or moredays of school and ob-served a median absolutereduction of 10.8 per-centage points (range ofvalues: 1.2 to 16.2 per-centage point reduction).The reduction in the pro-portion of children miss-ing school was 6 percent-age points for controlled

-of-life scorein study or could be calculated.

to graph if reported in study or

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points for uncontrolledtrials (Figure 7).Two studies measured

productivity outcomes dif-ferent from those reportedabove and thus could notbe included in the produc-tivityanalysis; these studiesfound inconsistent effects.One study69 combinedbothwork and school daysmissed as a measure ofproductivity and found a3% increase in the numberof children, adolescents, oradults missing at least 1day of work or school peryear but the increase wasnot signifıcant (p�0.62).Aecond study74 found a23.0 percentage-point re-duction in the proportionof children or adolescents missing 8 or more days of schoolper year (p�0.01).

Outcomes related to healthcare utilization. Eighteenstudies 57,69–72,74,75,78–82,85,87–90,93 measured changes inone ormore healthcare utilization outcomes. (Several stud-ies used more than one measure for each outcome. There-fore, the number of studies for each outcome may not addup to total number reported here.) Overall improvementswere small, with ten studies57,70,72,74,75,78,79,87,90,93 showingmedian reductionof 0.57isits per year (IQI: 0.33 to.71 visit per year reduc-ion) in the number ofcute care visits for asthmacontrolled trials: 0.37cute care visits per yeareduction; uncontrolledrials: 3.38 acute care visitser reduction) (Figure 8).he reduction in acute careisits included decreases of.40 hospitalizations perear (IQI: 0.10 to 1.45ospitalizations per yeareduction) from seventudies,70,74,75,79,87,90,93 de-rease of 0.2 emergencyoom visits per year (IQI:.11 to 0.5 visits per year re-uction) from eight stud-

Figure 6. Productivity: schNote: Gray box represents IQI orIQI, interquartile interval

Figure 7. Productivity: schoNote: Gray box represents intercould be calculated.

es,57,70,74,75,79,87,90,93 and pct pts, percentage points

decrease of 0.50 unscheduled offıce visits per year (rangeof values: 0.20 to 6.88 visits per reduction) from fourstudies.57,70,87,93

Eleven studies57,69,71,72,75,78,80,81,85,88,89 observed ame-ian absolute reduction of 5.4 percentage points (IQI: 1.6ercentage point increase to 19.2 percentage point de-rease) in the proportion of children or adolescents withne or more acute care visits for asthma in the past yearcontrolled trials: 5.4 percentage point reduction; uncon-rolled trials: 12.9 percentage point reduction) (Figure 9).

ays missed, mean number/yeare; CIs were added to graph if reported in study or could be calculated.

ays missed, % populationile interval or range; CIs were added to graph if reported in study or

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One study82 measured healthcare utilization outcomessing different measures than those reported above andhus could not be included in the analysis. This studyound no improvement in hospitalizations but did noteport specifıc data.

utcomes related to physiologic pulmonary func-ion. Seven studies57,68,71,75,88,94,109 measured physio-logic responses using pulmonary function testing.

Figure 8. Healthcare utilization: combined measure of acNote: Gray box represents IQI or range; CIs were added to graph if rep*Combined � sum of hospital, emergency department, and unscheIQI, interquartile interval

Figure 9. Healthcare utilization: percentage of children wiNote: Gray box represents interquartile interval or range; CIs were adcould be calculated.

IQI, interquartile interval; pct pts, percentage points

ugust 2011

Six studies57,68,71,75,88,109

were RCTs, and one94

was an uncontrolled be-fore-and-after study. Thestudies reported a varietyof pulmonary functionmeasures such as forcedexpiratory volume in 1second (FEV1), forced vi-tal capacity (FVC), andpeak flow. Two stud-ies75,88 showed signifıcantimprovement in pulmo-nary function testing. Onepaper88 found a 10.0 per-centage point absolute im-provement in percentagepredicted FEV1 and an 8.2percentage point absoluteimprovement in percent-age predicted peak flowcompared to control. Thesecond paper75 showed an

improvement in expiratory flowat 25%and50%vital capacityatendofinterventionbutdifferencesdisappearedby12-monthfollow-up. Five studies, however, found no overall improve-ment in pulmonary functionmeasures.

Outcomes in Adults with AsthmaThree68,69,91 of the 23 intervention studies included inhis review included adult participants. All three stud-

ies were RCTs.

Quality of life. Twostudies68,91 measured aQOL outcome. Onestudy68 found a 13% rela-tive improvement inquality-of-life or symp-tom scores (p�0.006).The other study found anonsignifıcant improve-ment in quality-of-life orsymptom scores of 5.3%(p�0.66).

Productivity. One study69

measured productivity andfound a 3% (p�0.62) non-signifıcant increase in theproportion of people whomissedmore than1workorschool day per year because

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Healthcare utilization. One study69 measured health-care utilization and found a nonsignifıcant 0.2 percentagepoint (p�0.85) decrease in the proportion of participantswith one or more acute care visits for asthma symptoms.

Additional Outcomes in Studies with Children,Adolescents, and Adults

Outcomes related to trigger levels. Eleven stud-ies57,70,71,78–80,82,86,88,102,118 measured the levels ofsthma triggers in the house before and after the inter-ention. Nine of those studies57,68,70,71,78–80,86,88,118

compared trigger levels with a control group, and twostudies82,102 used a before-and-after design. The mostcommon triggers measured were dust mite, cockroach,mold, mouse, cat, and dog allergens. Outcomes for irri-tants such as nitrogen dioxide and particulate matterwere also reported in two studies.71,82 Cotinine, a biolog-ical marker for ETS exposure, was measured in onestudy.79 Trigger levels decreased in the interventionrm compared to baseline in ten of 11 studies91%).57,70,71,79,80,82,86,88,102,118 However, in two ofthose studies82,102 the improvements in trigger levelsere not sustained over time. Four of the nine controlledtudies (44%)57,71,86,118 had a signifıcant decrease in ateast one asthma trigger compared to the control group.

utcomes related to trigger-reduction behav-ors. Twelve studies69,71,75,79–81,86,88,89,91,92,94 (nine con-trolled and three before-and-after studies) measuredchanges in TRBs. These are any behavior performed toreduce the level of asthma triggers in the home. Thebehaviors included washing bedding in hot water; us-ing allergen-impermeable mattress and pillow covers;following pest-management strategies such as cover-ing and sealing food; removing carpets; cleaning, vac-uuming, washing, or freezing stuffed animals; fıxingleaks and implementing other strategies for preventingor removing mold; and reducing exposure to ETS. All12 studies showed an improvement in TRBs comparedto before the intervention, and fıve69,80,81,86,88 of theine controlled studies showed improvement com-ared to the control group in at least one TRB. Use ofedding covers, ventilation, and household cleaningere the behaviors most often changed. Pet removalnd smoking cessation were the behaviors least oftenhanged.Twenty-one of the 23 studies included in this review pro-

ided some formof information related to smoking or ETS.f these, 1857,68,71,72,75,78–82,85–88,91–94 supplied informa-ion on the percentage of households with at least onemoker at baseline. Amedian of 45% of homes in the inter-entionarmof these studies containeda smoker (IQI: 38.2%

o 60.3%). Thirteen studies57,71,72,75,79–81,86,88–90,93,115 ex- i

plicitly indicated that smoking-cessation information,ETS counseling, or service referrals were provided as partof the intervention. Seven studies75,80,86,88,91,92,94 re-ported the percentage of caregivers that smoked or par-ticipants exposed to ETS before and after the interventionand found a median reduction of 7% (IQI: 5% to 13%reduction) for this outcome. Five of these stud-ies75,80,86,88,91 were controlled studies of whichour75,80,86,88 saw a decrease in the percentage of caregiv-rs smoking over the control group (range of values: 1%o 6.5% decrease) but none of the decreases were signifı-ant. Four71,80,86,89 of fıve studies71,80,81,86,89 that mea-ured changes in smoking behavior indicated that parentsr caregivers changed their smoking behaviors post-in-ervention by smoking outside the house, by reinforcinghat no smoking was permitted inside, or by providing amokefree room in the house. Two studies71,79 reportedbjective measures of ETS exposure before and after thentervention.One study79 measured urine cotinine levels before and

fter the intervention and found that the mean cotinineevel was reduced from 48.16 nanograms (ng)/mg creat-ine to 35.43 ng/mg creatnine in the intervention groupnd from 70.74 ng/mg creatnine to 53.82 ng/mg creat-ine in the control group. The reduction in mean coti-ine levels was not signifıcant between two groupsp�0.10) in the unadjusted regression model, but in thedjustedmodel the intervention group had a signifıcantlyreater reduction in mean cotinine levels from baselinep�0.02). Another study71 found that home ambient airparticulate levels, which have been associated with ETSexposure, decreased signifıcantly after the intervention.Five studies71,80,86,91,92 reported the number of parents

and caregivers of asthma sufferers who stopped smoking.Four of these studies71,80,86,91 specifıcally mentioned de-livery of ETS education during the home visit, and onetailored intervention86 provided extensive counseling onallergen avoidance. This same study,86 which reported aecrease in asthma exacerbations, speculated that theecrease was related to ETS avoidance because no otherllergen decrease was reported.

utcomes related to asthma management behav-ors. Ten studies69,75,79–82,85,88,89,94 (six RCT and fourefore-and-after) measured and reported outcomes forMBs. These are any behaviors aimed at monitoring andontrolling asthma. The most common AMBs reportedere: using an asthma controller medication, havingn asthma management plan, using a peak flow meter,egularly visiting a primary care physician, being pre-cribed controller medications by a physician, and us-ng a spacer with an asthma inhaler. Nine of ten stud-

es69,75,79,81,82,85,88,89,94 reported improvements in

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asthmamanagement behaviors compared to baseline val-ues. The one study80 that did not show an improvementid not include self-management training as part of thentervention. Four of six controlled studies75,79,81,88

(67%) showed a signifıcant improvement in at least oneAMB compared to the control group. Having an asthmamanagement plan, being prescribed controller medica-tions, and increasing use of controller medication weremore commonly improved behaviors. Increased use of apeak flow meter was less commonly improved.

Outcomes related to asthma control. Seven stud-ies,68,79–81,86,87,89 fıve of them controlled trials, reportedn asthma control outcomes. These outcomes includedrequency of rescue-medication use, frequency of asthmaxacerbations, asthma control or severity scores, and fre-uency of oral steroid use. Five of seven studies79–81,86,87

showed improvement compared to baseline values in atleast one asthma-control outcome. However, comparedto the control group, only one81 of fıve controlled studieshowed a signifıcant improvement in at least one asthma-ontrol outcome.

Subgroup Analyses

Number of home visits. A comparison wasmade of thestudieswith four ormore home visits and the studieswithless than four home visits in outcomes with at least onestudy in each category. Controlled studieswithmore thanfour home visits showed slightly greater improvement inQOL, healthcare utilization, and productivity outcomesthan controlled studies with less than four visits. For theuncontrolled studies, studies with four or more homevisits did not show any greater improvement over studieswith less than four visits in most of the outcomes thatcould be measured (percentage of children with morethan 1 symptom-days, quality-of-life scores, mean num-ber of acute care visits per year, and school days missed).However the number of studies within each category istoo small (one to two studies) to draw any overallconclusions.

Type of remediation. Also compared were the type ofenvironmental remediation (major, moderate, or minor)in outcomes with at least one study in each category. Interms of quality of life, the controlled studies with mod-erate remediation showed a greater reduction in symptom-days and quality-of-life score improvements comparedwith major and minor remediation studies. In terms ofhealthcare utilization, there was a greater reduction inacute care visits per year as remediation intensity in-creased, although this difference was very small. In theuncontrolled studies, the results showed a similar pattern

for the quality-of-life and healthcare utilization out-

ugust 2011

comes. There were not enough studies in the productivityoutcomes to make any direct comparisons.

Summary of OutcomesOf 23 studies, 22 included children or adolescents andthree included adults. In studies including children andadolescents, QOL outcomes demonstrated clinicallymeaningful improvement and consistent effects acrossthe body of evidence, except for QOL scores, whichshowed improvement that was not clinically meaningful.In healthcare utilization studies including children andadolescents, the team found a borderline reduction inacute visits that was consistent across the evidence. Pro-ductivity outcomes in children or adolescents showedconsistent meaningful improvements across the body ofevidence. Most of the studies reporting physiologic out-comes in children and adolescents showed no signifıcantimprovements. In studies including adults, althoughthere were borderline improvements in QOL outcomes,not enough studies showed improvements to draw anydefınitive conclusions on the effectiveness of these inter-ventions. Most studies measuring the additional out-comes (trigger levels, TRBs, AMBs, and asthma control)demonstrated substantial improvements compared tobaseline.

ApplicabilityEighteen of 23 studies57,69–72,74,78–82,85,87–90,93,94 wereconducted in the U.S., three68,91,92 in the United King-om, one75 in Canada, and one86 in Japan. The U.S.tudies all took place in urban, inner-city locations in 15ifferent states. Two studies57,72 were multiple-site stud-

ies, each in seven cities across the U.S. (NY, Chicago,Boston, Seattle, Dallas, Tucson, and Boston). Two stud-ies68,92 were conducted in rural areas, both in the UnitedKingdom.Minority groups were well represented in this body of

evidence. In eight studies70–72,74,78,80,88,93 African Amer-icans represented the largest percentage of participants;in six studies57,79,81,82,90,115 Hispanics represented thelargest percentage of participants; in two studies69,89

whites represented the largest group; one study94 re-ported equal numbers of African-American and His-panic participants; one study87 reported 80% minoritypopulations; and one study86 included only Asian partic-pants. The remaining four studies68,75,91,92 did not re-ort on race or ethnicity.Eighteen studies57,68,70–72,74,78–82,85,88,90–94 were con-

ducted in low-income populations. The other fıve stud-ies69,75,86,87,89 did not provide income information. Theinterventionswereconductedby trainedpersonnel inawiderange of organizations including academic institutions,

healthcare clinics or systems, state and local health depart-

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ments, and community-based organizations. Trained per-sonnel most commonly were CHWs80–82,85,88,89,93,94 butnurses,68,69,75,79,91 respiratory therapists,87,90 socialworkers,72andphysicians70,86 also implemented these inter-ventions. The majority of studies were directed toward ur-ban, inner-city minority child and adolescent populationswith low SES—a population considered more at risk forpoor asthma control. However, given the diversity of studyand participant characteristics in this body of evidence, thereview team concluded that these interventions should beapplicable across a broad range of settings and asthmapopulations.

Other Positive or Negative EffectsMultiple studies68,69,79–82,88,89,115 identifıed improvedcaregiver support and improved quality of life as an ad-ditional benefıt of these interventions. Other benefıtsmentioned included improved family relationships,68

improved energy effıciency,68 greater communicationbetween caregivers and physicians,88 and improved rela-ionships between healthcare providers and the commu-ity.82 Additional benefıts postulated by the team were

the health benefıts of smoking cessation for the caregiver,the health benefıts of reducing triggers in the home forparents and siblings of children in the study, and identi-fıcation of additional health concerns, such as lead paint,as part of the home assessment.Potential harms of these interventions postulated by

the team included the expense of remediation, particu-larly major remediation, to the participant (if not paid bythe study). Additionally, the team hypothesized that re-modeling may increase triggers such as dust and volatileorganic compounds and worsen asthma and allergies.However, neither of these issues was reported in any ofthe reviewed studies. Another potential harm postulatedby the teamwas the danger to healthcareworkers of goinginto the home. However, this has not been the case in thefıeld. One study80 reported that only two of 1400 homeshad incidents requiring withdrawal of services because ofsafety concerns (Dr. Jim Krieger, oral communication,February 2008). In another study,69 the mean physicalafety rating by the nurses conducting the study was 3.6,hich fell between somewhat safe (3) and very safe (4).

Economic EfficiencyAn economic analysis126 of home-based, multi-trigger,multicomponent interventions with an environmentalfocus was conducted after the initial effectiveness reviewand appears in this issue.126 The economic fındings,based on the results of 12 studies described in 13 pa-pers,57,68,71,77,78,80,83,87,89,90,92,106,121 all of which werealso included in the assessment of effectiveness, are

briefly summarized here. All numbers were converted to

2007 U.S. dollars. Study cost per participant ranged from$231–$14,858 (12 studies). Interventions with major en-vironmental remediation had signifıcantly higher studycosts (range: $3796–$14,858; three studies) compared tointerventions with minor or moderate remediation(range: $231–$1720; nine studies).Six studies (all minor or moderate remediation studies

with an educational component) provided full economicsummary measures. Three provided cost–benefıt esti-mates, and three provided cost-effectiveness estimates.The three cost–benefıt ratios ranged from $5.3–$14.0,which suggests that these interventions provide substan-tial returns on each dollar invested. The three cost-effectiveness studies reported costs ranging from $12–$57 per additional asthma symptom-free day. This rangeis lower than the standard cut-off used in the cost-effectiveness literature and indicates good value formoney invested.127

Barriers to Intervention ImplementationSeveral barriers to implementation of this interventionwerementioned in the body of evidence, including reluc-tance of families to accept home visits,94,96 inability tomaintain follow-up due to a transient population,96,115

diffıculty scheduling appointments,69,85,114 and poorompliancewith recommendations.69,93 The teampostu-lated other potential barriers such as cost of the interven-tion (particularly major remediation) and whether inter-vention benefıts are maintained over time. Althoughsome studies72,82 found that benefıts (particularly reduc-tions in allergen levels) decreased over time, other studiesfound intervention behaviors and health effects were sus-tained. One study87 found that intervention materialsrovided by the study were still in use in the homes 1 yearfter the study ended. Two other studies57,72 found thateductions in symptom-days and hospital visits were stillustained 1 year after the intervention ended. Anotherotential barrier postulated by the team was the ability ofnterventions to obtain enough funding (i.e., insuranceeimbursement) to sustain the intervention over time.owever, a recent report by the U.S. Environmental Pro-ection Agency (EPA) found that several home environ-ental interventions have been successful in obtainingeimbursement from insurance companies.128

Research Issues

Effectiveness. Findings of this review indicate thathome-based, multi-trigger, multicomponent interven-tions are effective in reducing asthma symptom-days andschool days missed by children. Important questions stillremain regarding the intervention composition and in-tensity as well as effectiveness in different settings and

populations. Some of these questions include:

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● What are the independent contributions of particularintervention components to overall intervention effec-tiveness? Which components are the most importantfor inclusion in this intervention?

● What is the required intensity (number of home visits,intensity of remediation, intensity of education) neededfor an effective home environmental intervention?

● What impact does ETS have on the effects of this inter-vention? Should smoking-cessation counseling be anecessary component of all home-based environmen-tal interventions for asthma?

Applicability. This intervention has been studiedmostly in low-income, urbanminority populations but ismost likely effective in most settings and populations.The following questions remain about the applicability ofthis intervention in various settings and populations.

● How effective is this intervention in adult populations?● Are there differences in intervention effectiveness be-tween children and adolescents?

● How effective is this intervention in rural populations?● Is this intervention more effective in participants withmore severe asthma symptoms?

● How does the type of dwelling (apartment, duplex,single-family home) affect the effectiveness of theintervention?

Implementation. This intervention has been imple-mented in a variety of ways. However, questions stillremain as to what is the most effective and cost-effectiveway to implement this intervention in a “real-world set-ting.” These questions include:

● How should these interventions be integrated in thehealthcare system to ensure appropriate access andsustainability?

● Which asthma patients should these interventionstarget?

● Who are the most effective intervention implementers(e.g., CHWs, nurses, respiratory therapists) and doesthis change depending on intervention setting?

● Which intervention components are most importantto include?

● Would a scaled-back version of these interventions beas effective?

ConclusionThe systematic review described in this article providedthe evidence on which the Task Force based its fındingson the effectiveness of multi-trigger, multicomponent,home-based environmental interventions for reducingasthma. The review found that home-based environmen-tal interventions that targetmore than one asthma triggerand employ more than one intervention component

might successfully reduce asthma symptom-days and

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school days missed by children. These results are consis-tent with those from previous reviews and advisory pan-els that have examined similar interventions.14,56,129,130

Home-based, multi-trigger, multicomponent inter-ventions with an environmental focus provide an effec-tive way to target two of the four components consideredessential to effective asthma management, according tothe NAEPP Expert Panel Report Guidelines for the Diag-nosis and Management of Asthma (EPR-3):14 (1) provi-sion of self-management education for a partnership inasthma care; and (2) reduced exposure to indoor environ-mental triggers.14 Further, the guidelines put forth byNAEPP support the results found in this systematic re-view, that “effective allergen avoidance requires a multi-faceted, comprehensive approach” and “individual stepsalone are generally ineffective.” Other organizations,such as the Center for Managing Chronic Disease withthe Asthma Health Outcomes Project (AHOP), theGlobal Initiative for Asthma with the GINA report, andthe National Center for Healthy Housing with the Hous-ing Interventions and Health review have recently pub-lished guidelines stating that multifaceted home-basedenvironmental interventions are effective and ready forimplementation.14,56,129,130

The median attrition rate for these interventions at12 months was relatively low at 18%, indicating a lowdrop-out rate for most studies. The differential attritionrate between intervention and control groups was small,indicating that the intervention probably did not affectstudy attrition. Most of the RCTs did not provide a com-parison of the severity of asthma, even at baseline, amongdropouts in the study groups. Most of the attrition wasdue to loss at follow-up, and although small, it could haveaffected results.The body of literature in this review suggests that the

home visit, without any other components, may be anintervention in itself. Home visits provide a source ofsocial support for people with asthma and their caretak-ers. The benefıcial effect of home visits may also be due inpart to the Hawthorne effect, whereby subjects improveor modify aspects of their behavior in response to beingstudied or measured. This may explain why, in severalstudies in the current review, both the intervention andcomparison groups improved signifıcantly.One study in the review by Carter and others43 ran-

domized participants into three groups: an interventiongroup that received the full home visit, environmentaleducation, and remediation; a placebo group that re-ceived a home visit and ineffective environmental educa-tion and remediation; and a control group that receivedno home visits or other types of interventions. Both theintervention and the placebo group that received home

visits had a signifıcant decrease in acute healthcare use

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S22 Crocker et al / Am J Prev Med 2011;41(2S1):S5–S32

compared to the control group that did not receive homevisits. The fact that there were similar results for theintervention and placebo group could be because partic-ipants who received home visits weremore likely to cleantheir homes prior to the visit, which reduced asthmatriggers, or could be a placebo effect from the sham envi-ronmental education and remediation. These effects il-lustrate how studies could underestimate the benefıts ofhome-based environmental interventions if both the in-tervention and comparison group receive home visits.Although the home visit is not identifıed here as an inter-vention component, it clearly confers some benefıt.This model has the potential for more comprehensive

health benefıts. Even though all home visits in this reviewfocused primarily on asthma, several home-based envi-ronmental interventions in the communitymay combineasthma-related interventions with other health interven-tions, such as teaching lead-poisoning prevention andoffering vaccinations during the home visit.56 However,here was some concern that taking the focus of the inter-ention away from asthma couldmake the primary inter-ention objective less effective. More evidence is neededn the effectiveness of comprehensive home-based inter-entions that combine asthma interventions with otherublic health interventions.Many of the studies in this review used CHWs toerform the intervention. The literature indicates that its benefıcial to hire and train CHWs to implement thisntervention for the purpose of reaching out to primarilyow-income, ethnicminority populations. CHWs play anssential role in the implementation of interventions,ridging the gaps between underserved populations andesearchers.131–133 Because they are usually from thesame community, CHWs can connect culturally withlocal populations and build trusting relationships withclients and their families. This trust often allows clients todisclose more health needs to CHWs.131

One study in this review mentioned the initial reluc-tance of families of children with asthma to accept homevisits and how this barrier was overcome by using CHWsto gain the trust of the community.94 Brief home visitsnable CHWs to establish a comfortable, ongoing inter-ction with community members who participate in thentervention. This relationship allows them to become aaluable source of asthma education for these populationroups and at the same time an important resource forhe evaluation of the home environment.134,135 Severalstudies in the review discussed the importance and ben-efıts of using CHWs in the implementation of asthmainterventions. One study80 found that CHWs played acrucial role in providing education and support to studyparticipants, resulting in a signifıcant reduction in

asthma morbidity and decrease in healthcare services

used. In addition, the outcomes of several other stud-ies81,88,89,93,94 have similarly suggested that CHWs orasthma outreach workers contribute to an increased ef-fectiveness of asthma interventions and provide substan-tial help for the families of asthma patients. CHWs mayalso be more economical than other trained personnelsuch as nurses or respiratory therapists. However, nursesand other healthcare professionalsmay be able to addresshealth needs in more detail and greater depth. All thesefactors should be considered when choosing what type ofhealthcare worker will implement the intervention.Environmental tobacco smoke is a key asthma trigger

and was reported in a high percentage of homes in thisreview, yet only 13 studies included an ETS componentas part of the intervention.57,71,72,75,79–81,86,88–90,93,115

These components came in the form of education onavoiding ETS, behavioral education to decrease exposure,smoking-cessation counseling, or referral to cessationprograms. Addressing numerous other home environ-mental triggers without addressing ETS could blunt theeffects of these interventions. Studies that addressed ETSwere more successful at changing smoking behaviorsthan at attaining smoking cessation in the targeted pop-ulation, although some studies did report successfulsmoking cessation as a result of the intervention.71,80,86

Few studies specifıcally reported results on smokingbehavior, which makes it diffıcult to assess the success ofthe intervention at reducing ETS exposure. Most studiesthat did evaluate smoking behaviors used surveys beforeand after the intervention. The use of more objectivemeasures of ETS such as cotinine testing may also beuseful because subjective measures such as before-and-after surveys may not accurately reflect changes insmoking practices. The literature strongly suggeststhat ETS be considered at the same level of importanceas other asthma triggers and be an integral part of thestandard environmental assessment, education, andevaluation components in home-based environmentalinterventions.Very few studies in this body of literature evaluate

interventions conducting major remediation, whichmakes it diffıcult to comparemajor,moderate, andminorremediation studies in terms of effectiveness. Studies ofmajor remediation efforts showed effectiveness in severaloutcomes, but they did not clearly show a greater effectthan interventions conducting moderate and minor re-mediation. In fact, inmost of the quality-of-life outcomesstudies with moderate remediation showed the greatesteffect sizes. Implementers must weigh the potential ben-efıts of increased remediation intensity against the addedcost. The review team is aware of and awaits the results of

several ongoing major remediation studies.

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Despite strong evidence of effectiveness in quality-of-lifeand productivity outcomes, the team found no signifıcantimprovement in physiologic measures (only two of sevenstudies showed any signifıcant improvement in pulmonaryfunction testing).Pulmonary function testing isused inclin-ical practice and is recommended by theNAEPP guidelinesto guide asthma diagnosis and treatment decisions for indi-viduals. Fuhlbrigge and colleagues136 demonstrated that aow absolute value of %FEV1 in pediatric patients does pre-ict the occurrence of ED visits and hospitalizations forsthma in the 4-month period following spirometry. How-ver, several studies have shown very little correlation be-ween changes in pulmonary function testing on a popula-ion level and any of the other measures of asthmatatus.137,138 Therefore, the absolute values in FEV1may bemore predictive than changes in FEV1 at a population levelin predicting clinical outcomes. In addition, most childrenin these studies had a percentage predicted FEV1 that wasrelatively normal at baseline, which is often the case inasymptomatic children with mild or moderate persistentasthma.When FEV1 is normal or shows onlymild obstruc-tion at baseline, the amount of improvementwill be smaller,thus, making it more diffıcult to reach signifıcance.Most interventions in this review were tailored to cli-

ent exposure to asthma triggers in the home, the client’sallergen sensitivities by skin testing or specifıc immuno-globin E (IgE) levels, or both. Interventions tailored toexposure or sensitivity may be more costly and time-consuming initially, due to the additional efforts neededto assess the client’s trigger exposure and allergen sensi-tivity, butmay ultimately be less costly and time-consum-ing because clients are given only necessary educationand remediation. Not enough studies within each out-comewere identifıed in this review tomake any defınitiveconclusions or recommendations about how tailoringhome environmental interventions to client exposure orallergen sensitivity affects outcomes. Implementersshould consider these benefıts with other factors, such ascost and time, when deciding if tailoring is worthwhile.Five studies evaluating interventions targeted at in-

door asthma triggers and with similar components to theones used in the 23 studies included in this review werepublished after the literature search period ended.139–143

The fındings reported in these fıve studies agree in sizeand direction with the fındings of this review. A recentlypublished systematic review on home-based interven-tions for childrenwith asthma reports fındings consistentwith those of the current review.144 That review focusedsolely on interventions conducted by CHWs, whereasthis review includes interventions conducted by severaltypes of trained personnel. In addition, that review in-cluded only interventions targeting children or adoles-

cents, whereas this review includes interventions target-

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ing children or adolescents and adults. Four of sevenstudies included in that review are also included in thissystematic review. Three studies included in that reviewwere excluded from this review for several reasons: onewas published after the search dates; one was excludedbecause it did not include health outcomes; and one wasexcluded because it did not meet Community Guidequality-of-execution criteria.This review has some limitations. The home-based,

multi-trigger,multicomponent, environmental interven-tions in this review were extremely heterogeneous. Theoutcomes and effect measures varied among studies.Some outcomemeasures, such as emergency room visits,hospitalizations, and unscheduled outpatient visits weresimilar enough to combine. Other outcomes, however(e.g., symptom-days, QOL scores), were too disparate tocombine. Additionally, effect measures differed amongstudies: some studies reported in percentages and othersin mean numbers, and these measures could not be com-bined. Because the data were too heterogeneous, the teamopted to summarize data using descriptive statisticsrather than meta-analysis.Another challenge to evaluating multicomponent in-

terventions is the diffıculty in isolating the effect of onecomponent from those of other components. Further, thestudies included various combinations of componentsand targeted various types of asthma triggers, which addsto the diffıculty when using these fındings to implementinterventions. In this review, the team was largely unableto assess the specifıc benefıt of each component in theintervention because not enough studies with similarcomponents measured comparable outcomes. Most ofthe studies in this review did not blind participants orimplementers to group assignment because the nature ofthe intervention made blinding diffıcult. Four stud-ies57,70,71,79 were able to conduct some form of blinding.he lack of blinding inmost studies could produce biasedesults. Finally, systematic reviews are prone to publica-ion bias. The team attempted to minimize this bias byonsidering unpublished studies, such as government re-orts and unpublished manuscripts, in addition to pub-ished data sources. One study included in the fınal re-iew87 is an unpublished government report. Anotherstudy81 in the review had not been published at the timeof inclusion but was published later in 2009.62

Based on Community Guide methods,64 this reviewidentifıed evidence that multi-trigger, multicomponent,home-based environmental interventions were effectivein reducing the number of symptom-days and schooldays missed because of asthma among children and ado-lescents. These interventions also resulted in a modestreduction in asthma-related healthcare utilization. The

review team found insuffıcient evidence to determine

S24 Crocker et al / Am J Prev Med 2011;41(2S1):S5–S32

the effectiveness of this intervention in adults because ofthe small number of and inconsistent results from quali-fying studies. Additional research is needed on the useand impact of these interventions for adults with asthma.The effectiveness of these interventions may vary fordifferent asthma populations. Implementers will need toadapt these interventions to meet their available re-sources and the individual needs of their community.

The authorswould like to thank theCoordination andConsult-ing teams for their valuable contribution to this paper. Thenames and affıliations of the Coordination and ConsultingTeams are listed in Appendix B.Points of view are those of the Task Force on Community

Preventive Services and do not necessarily reflect those of theCDC.The work of Stella Kinyota, Gema Dumitru, and Briana

Lawrence was supported with funds from the Oak Ridge Insti-tute for Scientifıc Education (ORISE).Publication of this article was supported by the Centers for

Disease Control and Prevention through a Cooperative Agree-ment with the Association for Prevention Teaching and Re-search award # 07-NCHM-03.No fınancial disclosures were reported by the authors of this

paper.

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107. Kattan M, Crain E, Steinbach S, et al. A randomized clinical trial ofclinician feedback to improve quality of care for inner-city childrenwith asthma. Pediatrics 2006;117(6):1095–103.

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109. Klinnert MD, Liu AH, Pearson MR, et al. Outcome of a randomizedmultifaceted intervention with low-income families of wheezing in-fants. Arch Pediatr Adolesc Med 2007;161(8):783–90.

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111. Leung R, Koenig J, Simcox N, van Belle G, Fenske R, Gilbert S.Behavioral changes following participation in a home health promo-tional program in King County, Washington. Environ Health Per-

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117. Parker E, Baldwin G, Israel B, Salinas M. Application of health pro-motion theories and models for environmental health. Health EducBehav 2004;31(4):491–509.

118. RichardsonG, BartonA, BashamM, Foy C, Eick S, SomervilleM. TheWatcombe housing study: the short-term effect of improving housingconditions on the indoor environment. Sci Total Environ 2006;361(1–3):73–80.

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123. Takaro T, Krieger J, Song L. Effect of environmental interventions toreduce exposure to asthma triggers in homes of low-income childrenin Seattle. J Expo Anal Environ Epidemiol 2004;14(1S):S133–S143.

124. Vesper S, McKinstry C, Yang C, et al. Specifıc molds associated withasthma in water-damaged homes. J Occup Environ Med 2006;48(8):852–8.

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126. Nurmagambetov TA, Barnett SBL, Jacob V, et al. Economic value ofhome-based, multi-trigger, multicomponent interventions with anenvironmental focus for reducing asthma morbidity: a CommunityGuide systematic review. Am J Prev Med 2011;41(2S1):S33–S47.

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Appendix A: Glossary and Abbreviations

Allergen An antigen that causes allergic disease1Asthma control The degree to which the manifestations of

sthma (symptoms, functional impairments, and risks of untowardvents) are minimized and the goals of therapy are met14Asthma educationGeneral education on asthma without a self-anagement componentAsthma-management behaviors (AMB) Use of asthma controlleredications, use of asthma action plans, use of peak flow meters anddditional behaviors aimed atmonitoring and controlling asthmaAsthmatriggersAllergensandirritants that induceasthmasymptomsComponent A primary element of an intervention delivered toroduce a desired outcome; for example, environmental educationo reduce asthma morbidityCommunityHealthWorker (CHW)Members of the communityho, byperformingpreventivemedical services,monitoring the com-unity’s health, and identifying patients at particular risk, act as liai-ons between the community and the health system, interpret theocial climate, provide basic curative services, and enhance the out-each and effectiveness of health services to underserved populationsith the specifıc mission of reducing the impact of a single illness2,3Coordinated care Services to improve coordination of care be-

tween healthcare providers and home health workers

us

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S28 Crocker et al / Am J Prev Med 2011;41(2S1):S5–S32

Environmental education Patient education regarding actionsto reduce triggers in the homeEnvironmental remediation Actions conducted or fınanced to

reduce triggers in the homeEnvironmental remediation, major Major structural im-

provements to the home, which may include some combination ofcarpet removal, replacement of ventilation systems, or extensiverepairs to restore structural integrity (e.g., to roof, walls, floors)

Environmental remediation, moderate Providing multiplelow-cost materials with the active involvement of the trained homevisitor(s); activities in this category may include providing andfıtting mattress and pillows with allergen-impermeable covers, in-stalling small air fılters and dehumidifıers, integrated pest manage-ment, professional cleaning services or equipment, and minor re-pairs of structural integrity (e.g., patching holes)

Environmental remediation, minor Minor changes to thehome, which at a minimum include providing advice on recom-mended environmental changes to be performed by the membersof the household andmay include providing low-cost items such asmattress and pillow allergen-impermeable coversEnvironmental assessment In-home written assessment of en-

vironmental triggersEnvironmental tobacco smoke (ETS) Smoke from other peo-

ple’s tobacco products that may be involuntarily inhaledHome visitVisit to the home by a trained or experienced person

or people with the purpose of changing the home environment toreduce asthma triggersMajor environmental remediation See Environmental reme-

diation, majorModerate environmental remediation See Environmental re-

mediation, moderateMinor environmental remediation See Environmental reme-

diation, minorMultifaceted interventionComprehensive intervention that, in

this systematic review, focuses on more than one asthma triggerMulti-trigger Activities that reduce exposure to two or more

environmental triggers that exacerbate asthmaMulticomponent intervention Intervention that includesmore

than one componentSelf-management education (SM) Teaches problem-solving

skills that allow patients to identify their health problems, andprovides techniques to help themmake decisions, take appropriateactions, and modify these actions as needed as they encounterchanges in circumstances or disease4Social services Services to improve access to medical care or to

advocate for environmental remediation

Tailored environmental intervention Intervention with ed-cation and remediation efforts that accommodates the client’specifıc allergen sensitivities and environmental exposuresTrigger-reduction behaviors (TRB) application of behavioral

trategies for preventing and/or reducing asthma triggers in theome (e.g., washing bedding in hot water, using allergen-imper-eable mattress and pillow covers, counseling for smokingessation)

Abbreviations

AA African AmericanAC Asthma controlAE Asthma educationAMB Asthma-management behaviorsCC Coordinated careCHW Community health workerEA Environmental assessmentEE Environmental educationER Environmental remediationETS Environmental tobacco smoke (also called “secondhand

smoke”)HCU Healthcare utilizationIQI Interquartile intervalNR Not reportedPHYS Physiologic outcomesPRO ProductivityQOL Quality of lifeSM Self-managementSS Social servicesTRIG Asthma trigger indicatorsTRB Trigger-reduction behaviorsVOC Volatile organic compounds

References for Appendix A

1. Johansson S, Bieber T, Dahl R, et al. Revised nomenclature forallergy for global use: report of the Nomenclature Review Com-mittee of the World Allergy Organization, October 2003. J Al-lergy Clin Immunol 2004;113(5):832–6.

2. U.S. Health Resources and Services Administration, Bureau ofHealth Professions. Community health workers national work-force study. Rockville MD: HRSA, 2007. http://bhpr.hrsa.gov/healthworkforce/reports/chwbiblio07.pdf.

3. International Medical Volunteers Association. www.imva.org/Pages/chws.htm.

4. Bodenheimer T, Lorig K, Holman H, Grumbach K. Patient self-management of chronic disease in primary care. JAMA 2002;288(19):2469–75.

www.ajpmonline.org

Crocker et al / Am J Prev Med 2011;41(2S1):S5–S32 S29

A

Appendix B: Systematic Review Development Team

Coordination Team

CDC

Deidre Crocker, MD ............................................................ Air Pollution and Respiratory Health Branch, National Centerfor Environmental Health (APRHB)

Stella Kinyota, MD, MPH..................................................... APRHB

Gema Dumitru, MD, MPH.................................................... APRHB

Colin Ligon, CDC experience fellow...................................... APRHB

Elizabeth Herman, MD ........................................................ APRHB

Tursynbek Nurmagambetov, PhD ......................................... APRHB

David Hopkins, MD, MPH.................................................... Community Guide Branch, Epidemiology and AnalysisProgram Office (Community Guide)

Briana Lawrence, MPH, PhD candidate ................................ Community Guide

Sarah Merkle, MPH ............................................................ Division of Adolescent and Student Health, National Centerfor Chronic Disease Prevention and Health Promotion

External Partners

Denise Dougherty, PhD ....................................................... Agency for Healthcare Research and Quality

Katherine Pruitt, PhD .......................................................... American Lung Association

Alisa Smith, PhD ................................................................ U.S. Environmental Protection Agency

Kurt Elward, MD ................................................................. American Academy of Family Physicians

Task Force Member

Ned Calonge, MD ............................................................... Colorado Department of Public Health

Consulting Team

James Krieger, MD, MPH .................................................... Clinical Professor of Medicine and Health Sciences, Chief,Chronic Disease and Injury Prevention Section, PublicHealth—Seattle and King County

Megan Sandel, MD, MPH.................................................... Assistant Professor of Pediatrics, Boston University Schoolof Medicine

David Jacobs, PhD.............................................................. Director of Research, National Center for Healthy Housing

Darryl C. Zeldin, MD ........................................................... Molecular & Cellular Biology Group Respiratory &Cardiovascular Diseases, National Institute onEnvironmental Health Sciences (NIEHS)

Abstraction Team

Deidre Crocker, MD ............................................................ CDC/APRHB

Stella Kinyota, MD, MPH..................................................... CDC/APRHB

Gema Dumitru, MD, MPH.................................................... CDC/APRHB

Elizabeth Herman, MD ........................................................ CDC/APRHB

Sheri Disler, MS................................................................. CDC/APRHB

Colin Ligon, MD.................................................................. CDC/APRHB

ugust 2011

iIfCiCfBi

rstmcs

wocjelo

aipfggshAw

S30 Crocker et al / Am J Prev Med 2011;41(2S1):S5–S32

Appendix C: MethodsResults of each study were represented as change in quality of life,healthcare utilization, productivity, and physiologic measures at-tributable to the intervention and presented separately for childrenand adults; where possible, percentage point (i.e., absolute) changefrombaseline or comparison value in children or adults or bothwasused as the measure of effect. Percentage point changes and base-line rates were calculated as follows:For studieswith before-and-aftermeasurements and concurrent

comparison groups:(Ipost – Ipre) – (Cpost – Cpre); baseline: IpreFor studies with post-onlymeasurements and concurrent compar-ison groups:(Ipost – Cpost); baseline: CpostFor studies with before-and-after measurements and no concur-rent comparison groups:(Ipost – Ipre); baseline: IpreWhere:

Ipost Last reported percentage of intervention group afterntervention;pre Reported percentage of intervention group, immediately be-ore intervention;post Last reported percentage of comparison group afterntervention;pre Reported percentage of comparison group, immediately be-ore intervention; andaseline Estimated study population in the absence of or prior tontervention.When the effect was reported as an OR or a percentage (i.e.,

elative) change from baseline or comparison value, the teamought to convert the estimate to percentage point change. Ifhis was not possible, the outcome was excluded from the sum-ary effect measure but reported separately to reflect theomplete evidence base and to assess consistency across alltudies.Studies withmultiple effect estimates were handled in one of twoays. First, when there was more than one estimate for a singleutcome in a single study arm, consistent rules were applied tohoose the most appropriate estimate. For example, estimates ad-usted for confounding were selected over crude estimates; whenstimates were taken at multiple follow-up points, the estimate atongest follow-up was selected over those measured earlier. Sec-

nd, when estimates within a study differed in terms of population

nd intervention and therefore provided relatively independentnformation on effectiveness, they were treated as separate dataoints in the analyses. This approachwas usedwhenmore than oneorm of the intervention of interest was evaluated in separate studyroups or when the same intervention was evaluated in distincteographic areas or subpopulations. These estimates were usedeparately because they enhanced our ability to assess for effecteterogeneity by intervention characteristics or by setting context.s a result, the number of effect estimates reported in the reviewsas often greater than the number of studies.

Summarizing Effectiveness Evidence andTranslating into Recommendations

For each review, effect estimates across all related studies were sum-marized using the median as the descriptive statistic. When seven ormore effect measures were available, interquartile intervals were usedas themeasure of variability; otherwise, a range of values is presented.The Community Guide characterizes evidence for determining in-

tervention effectiveness as insuffıcient, suffıcient, or strong on thebasis of the number of available studies, the suitability of study designfor evaluating effectiveness, the quality of execution, the overall con-sistency of results, and themagnitude of effect. Evidence is consideredsuffıcient or strong when the body of evidence is of suffıcient size andquality to support conclusions, when reported effects are consistentand in the favorable direction, andwhen themagnitude of effect is, inthe judgment of the Task Force, large enough to be of public healthimportance. If these conditions are not met, evidence is consideredinsuffıcient to determine effectiveness. Insuffıcient evidence shouldnot be interpreted as evidence of ineffectiveness but rather as anindication that additional research is needed.Task Force recommendations link directly to the strength of evi-

dence on effectiveness, as described elsewhere.1 In brief, a fınding ofstrong or suffıcient evidence of intervention effectiveness leads to aTask Force recommendation favoring use of the intervention. Insuf-fıcient evidence leads to a recommendation for additional research.

References for Appendix C

1. Briss P, Zaza S, Pappaioanou M, et al. Developing an evidence-based Guide to Community Preventive Services—methods.Task Force on Community Preventive Services. Am J PrevMed2000;18(1S):S35–S43. www.thecommunityguide.org/methods/

methods-ajpm-developing-guide.pdf.

www.ajpmonline.org

Appendix D: Summary of evaluated studies: demographics

StudyStudydesign Study location N Age range Race/ethnicity

l Educationalcomponent Home visits

Type of homevisitor

Barton200768

gRCT Watcombe (inTorquayUK)

126 0–65� yrs NR NR 1 Nurse

Brown200669

iRCT Grand RapidsMI

239 57% �18yrs; 43%�18 yrs

56% white; 30AA

EE, SM 1 Nurse

Carter200170

iRCT Atlanta GA 104 5–16 yrs 92% AA NR 4 Physician

Eggleston200571

iRCT Baltimore MD 100 6–11.9 yrs 98% AA EE, SM 3 Environmentaleducator

Evans199972

iRCT Multisite (8U.S. cities)

1033 5–11 yrs 76% AA; 17%Hispanic

NR NR; 1 pest-controlvisit

Social worker

Hasan200374

Before-and-after

Flint MI 142 2–10 yrs 54% AA; 43%white

EE, SM 4 (and one schoolvisit; follow-upphone calls)

Social worker,nurse,respiratorytherapist

Hughes199175

iRCT Nova ScotiaCanada

95 6–10 and11–16yrs

NR EE, SM 2 Nurse

Kercsmar200678

iRCT Cleveland OH 62 2–17 yrs 82% AA; 17%white

EE, SM 4 Trainedsanitarians

Klinnert200579

iRCT Denver CO 181 9 mos to 4yrs

55% Hispanic33% AA; 23white

EE, SM 15 visits (avg) Nurse

Krieger200580

iRCT Seattle WA 274 4–12 yrs 31% AA; 25%Vietnamese17%Hispanic;12% white

EE 5–9 CHW

Krieger200881

iRCT Seattle WA 309 3–13 yrs 49% Hispanic14% AA; 13Vietnamese9% white

NR 1–5 home; 4 clinic CHW andnurse

(continued on next page)

Crockeretal/Am

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2011;41(2S1):S5–S32S31

August2011

and characteristics

SES TailoredAsthmaseveritya

Interventioncomponents

Type ofenvironmentaremediation

Low SES No Mild EA, ER Major

% NR No All severitytypes

AE, EA, EE,SM

None

Low SES No NR EA, EE, ER Moderate

NR Yes: exposureandsensitivity

Mild EA, EE, ER Moderate

Low SES Yes: exposureandsensitivity

Moderate tosevere

EA, EE, ER,SM, SS

Minor

Low SES No Moderate tosevere

CC, EE, SM None

NR Yes: exposureandsensitivity

All severitytypes

EA, EE, SM None

Low SES No Mildpersistent

EA, ER, EE,SM

Major

;%

Low SES Yes: exposure Wheezingnoasthmadiagnosis

EA, EE, ER,SM, SS

Moderate

;Low SES Yes: exposure Persistent EA, EE, ER,

SSModerate

;%;

Low SES Yes: exposureandsensitivity

Persistent CC, EA, EE,ER, SM,SS

Moderate

Appendix D: Summary of evaluated studies: demographic

StudyStudydesign Study location N Age range Race/ eth

Levy200682

Before-and-after

Boston MA 58 4–17 yrs 70% Hisp28% AA

Morgan200457

iRCT Multisite (7U.S. cities)

937 5–11 yrs 40% Hisp37% AA

Nicholas200585

Before-and-after

Harlem (NewYork City)NY

314 0–12 yrs 43% whiteLatino;black/L28% AA

Nishioka200686

CT Japan 36 2–7 yrs Japanese

Oatman200787

Before-and-after

MinneapolisMN

64 �18 yrs 80% mino

Parker200788

iRCT Detroit MI 298 7–11 yrs 83% AA; 1Hispani

Primomo200689

Before-and-after

Tacoma WA 71 �18 yrs 68% whiteAA

Shelledy200590

Before-and-after

Little Rock AR 18 3–18 yrs 50% Hisp27% wh

Smith200591

iRCT Norfolk andSuffolk UK

92 Adults NR

Somerville200092

Before-and-after

Cornwall UK 114 �3 to �16yrs

NR

Stout199893

Before-and-after

Seattle WA 23 1–9 yrs 87% AA

Thyne200694

Before-and-after

San FranciscoCA

65 0–12� yrs 43% Hisp43% AAAsian

aAsthma severity is based on a majority of asthma clients in that category as rAA, African American; AE, asthma education; avg, average; CC, coordinated careremediation; gRCT, group RCT; iRCT, individual RCT; mos, months; NR, not rep

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s and characteristics (continued)

nicity SES TailoredAsthmaseveritya

Interventioncomponents

Type ofenvironmentalremediation

Educationalcomponent Home visits

Type of homevisitor

anic; Low SES No Moderatepersistent

EA, EE, ER,SM, SS

Major EE, SM 2–6 CHW andnurse

anic; Low SES Yes: exposureandsensitivity

Moderate tosevere

EA, EE, ER Moderate EE 5–7 Researchassistantand pestcontrolprofessional

39%atino;

Low SES Yes: exposure All severitytypes

EA, EE, ER,SM, SS

Moderate EE, SM 6 CHW

NR No Mild tomoderate

EA EE, ER Moderate orminor

EE 12 Physician

rity Low SES Yes: exposureandsensitivity

Moderatepersistent

AE, EA, EE,ER

Moderate EE, SM 3 Respiratorytherapist

1%c

Low SES Yes: exposureandsensitivity

Moderate toseverepersistent

AE, EA, EE,ER, SS

Moderate EE 9 CHW

; 19% NR Yes: exposure All severitytypes

EA, EE, ER,SM

Minor EE, SM 2 CHW

anic;ite

Low SES Yes: exposure Moderate tosevere

CC, EA, EE,ER, SM

Minor EE, SM 8 Respiratorytherapist

Low SES No Severe AE, EE, SM,SS

None EE (minor),SM

4 Nurse

Low SES Yes: exposure Moderate tosevere

EA, ER Major NR 2 Housingofficer

Low SES Yes: exposure Moderate tosevere

CC, EA, EE,SM, SS

None EE, SM(with AE)

8� CHW

anic;; 11%

Low SES No Persistent CC, EA, EE,SM, SS

None EE, SM 2–3 CHW

eported in the article; CHW, community healthcare worker; CT, controlled trial; EA, environmental assessment; EE, environmental education; ER, environmentalorted; SM, self-management; SS, social services; UK, United Kingdom; yrs, years

Crockeretal/Am

JPrevMed

2011;41(2S1):S5–S32