““Dietary advice given by a Dietary advice given by a dietitian versus other healthdietitian versus other health

professional or self-help professional or self-help resources to reduce blood resources to reduce blood

cholesterol”cholesterol”(Review Article)(Review Article)

Thompson RL, Summerbell CD, Hooper L, Higgins Thompson RL, Summerbell CD, Hooper L, Higgins JPT, Little P, Talbot D, Ebrahim SJPT, Little P, Talbot D, Ebrahim S

The Cochrane LibraryThe Cochrane Library2009, Issue 42009, Issue 4

Presented by Samira Jones-BHS intern

6/29/10

OverviewOverviewAbstractBackground/IntroductionLiterature ReviewMethodologyResultsDiscussion/Application of ResultsConclusionReferences

AbstractAbstractBackground The average level of blood cholesterol is an important determinant of the risk of

coronary heart disease. Blood cholesterol can be reduced by dietary means. Although registered dietitians (RDs) are trained to provide dietary advice, for practical reasons it may be given by other health professionals or using self-help resources.

Objectives To assess the effects of dietary advice given by a RD compared with another

health professional, or the use of self-help resources, in reducing blood cholesterol in adults.

Search strategy Electronic databases- EPOC, EMBASE, CINAHL, and The Cochrane Library Hand searches- Conference proceedings Discussions with experts about their researchSelection criteria Randomized trials of dietary advice given by a RD compared with another health

professional or self-help resources. The main outcome was difference in blood cholesterol between RD groups compared with other intervention groups.

Data collection and analysis Two reviewers independently extracted the data and assessed study quality.

Abstract cont’d.Abstract cont’d.Main Results Total of 12 studies- 13 comparisons included in the review Participants receiving advice from RDs experienced a greater

reduction in blood cholesterol than those receiving advice only from MDs (-0.25 mmol/L (95% CI -0.37, -0.12 mmol/L)).

No statistically significant difference in change in blood cholesterol between RDs and self-help resources (-0.10 mmol/L (95% CI -0.22, 0.03 mmol/L)) was found.

No statistically significant differences were detected for secondary outcome measures between any of the comparisons with the exception of RD vs. Nurse for HDL-c, where the RD group showed a greater reduction (-0.06 mmol/L (95% CI -0.11, -0.01)) and RD versus Counselor for body weight, where the RD group showed a greater reduction (-5.80 kg (95% CI -8.91, -2.69 kg)).

Conclusions RDs were better than MDs at lowering blood cholesterol in the

short to medium term, but there was no evidence that they were better than self-help resources.

There was no evidence that RDs provided better outcomes than Nurses. The results should be interpreted with caution as the studies were not of good quality and the analysis was based on a limited number of trials.

BackgroundBackgroundCardiovascular disease (CVD) is the

leading cause of death in the U.S. ◦ Common forms are coronary heart disease (CHD) or

atherosclerosis◦ In 2006, CVD accounted for 831,000 deaths—34

percent of all deaths in the United States; main form of deaths were CHD, which caused 425,000 deaths

◦ The projected economic cost in 2010 for these diseases is expected to be $705 billion, 23 percent of the total economic costs of illness, injuries, and death.

◦ Certain population groups have higher prevalence of CVD than others including women and minorities.

BackgroundBackgroundRisk Factors contributing to CVD

◦Heredity (Genetics & Family history)◦Age

45 yrs. for men and 55 yrs. for women◦Environment & Lifestyle Behaviors

Diet* Physical inactivity Smoking Presence of other health conditions (i.e.

type 2 diabetes)

IntroductionIntroductionFramingham Heart Study

◦ Longitudinal cohort study that began in 1942 and established that high blood cholesterol is a risk factor for CHD. Results showed that the higher the cholesterol level, the greater the CHD risk. However, CHD is uncommon at total cholesterol levels below 150 milligrams per deciliter (mg/dL) according to the evidence.

Lipid Research Clinics-Coronary Primary Prevention Trial◦ In 1984, a direct link between high blood cholesterol and CHD was confirmed

which showed that lowering total and LDL ("bad") cholesterol levels significantly reduces CHD.

◦ More recent trials of cholesterol lowering drugs using statins have demonstrated conclusively that decreasing total cholesterol and LDL-cholesterol reduces the chance of having a heart attack, needing bypass surgery or angioplasty, and dying of CHD-related causes.

Dietary Prevention research for CVD ◦ In 2002, a review of studies found diets high in nonhydrogenated unsaturated

fats, whole grains, an abundance of fruits and vegetables, and adequate omega-3

fatty acids can offer significant protection against CHD.

IntroductionIntroductionGenerally speaking…

◦RDs are experts in food and health promotion and provide dietary and nutrition advice

◦Nurses provide care, treatment, and education regarding health and disease management

◦MDs diagnose, treat, and provide advice on healthy lifestyle maintenance and disease management under restrictive time constraints

Research Question?Research Question?What is the relative efficacy of

dietary advice given by a dietitian compared to other health professional, or using self-help resources in reducing blood cholesterol levels?

Other Research ObjectivesOther Research ObjectivesTo determine the effect of other

factors on the effectiveness of reducing blood cholesterol such as...

1. Participants at high risk vs. low risk of CHD 2. Dietary intervention use only or multiple

lifestyle interventions (i.e. smoking cessation + DI, physical activity + DI)

3. Length of follow-up 4. Setting for dietary advice 5. Contact time with the health professional 6. Concurrent use of lipid-lowering drugs

Literature ReviewLiterature ReviewWhat is a meta-analysis?

◦ The systematic, organized, and structured review and evaluation of a problem of interest using aggregated data from the literature of comparable studies.

◦ Used most in epidemiological and biomedical sciences

What is comparative effectiveness research (CER)? ◦ The comparison of existing interventions to

determine which poses the greatest benefits and harms for which patients/participants.

Literature ReviewLiterature ReviewLimited research comparing dietary

advice in adopting healthy eating habits to reduce blood cholesterol levels among general population

Study listed in the review paper◦Neil et al. conducted a British trial

comparing the effects of dietary advice given by a nurse, RD, or self-help leaflet Results: Regression to the mean effects

reduced the fall in blood cholesterol to 1.5% for all comparison groups.

Literature ReviewLiterature ReviewSchryver and Smith published a 2006

paper in Public Health Nutrition that reviewed qualitative data from the focus groups of 74 adults, 18-91 yrs. about their perceptions regarding dietary advice from MDs vs. RDs ◦Results: Participants believed MDs are not

qualified to give dietary advice and would not likely comply unless coming from a RD

◦No biomarkers used in study, solely anectdotal

MethodologyMethodologyRandomized controlled trials (RCT)Age: 18yrs and upGender: Males and FemalesNo pre-existing heart disease conditionsSetting: free-living, non-hospitalized or

institutionalizedTypes of Interventions: All dietary advice

to reduce blood cholesterol given by an RD or nutritionist compared to MD, nurse, other health care professional, or self-help resource

MethodologyMethodologyStudies where meals were provided were

excludedTwo reviewers assessed inclusion criteria

using the Effective Practice and Organization of Care (EPOC) review checklist◦ Kappa= 0.68 agreement between reviewers

Search strategy◦ Electronic Databases

The Cochrane Library (to Issue 3 2002) • EPOC trial register (October 2002) MEDLINE (1966 to September 2002) • EMBASE (1980 to September 2002) Cinahl (1982 to August 2002) • Human Nutrition (1991 to 1998) Science Citation Index • Social Sciences Citation Index

MethodologyMethodology◦ Hand searches- Conference proceedings on

nutrition and heart disease◦ Contacted experts in the field, first authors

of studiesOutcome measures:

◦1) Difference in blood cholesterol levels between RD group and other groups

◦2) Change in LDL-c, HDL-c, BMI, and blood pressure from baseline to follow up

MethodologyMethodologyData Collection

◦ Number of subjects◦ Baseline and final values◦ Mean (S.D.) change for both intervention &

control groupsData analysis

◦ Continuous variables were measured- total blood cholesterol, LDL-c, HDL-c, BMI, and blood pressure

◦ Random effects model was used to calculate un-standardized mean differences

◦ Chi-square X² tests for differences overall effects

ResultsResultsTwelve (12) studies met inclusion

criteria were used Studies were carried out in the U.S., UK,

Canada, or Australia for 6 wks-104 wks◦Settings: General practice, Workplace,

ClinicsThirteen (13) comparisons

◦ Four (4) RD vs. MD◦ Seven (7) RD vs. self-help◦ One RD vs. nurse ◦ One RD vs. counselor

ResultsResultsOutcomes of the interventions:

◦4 trials measured HDL-c◦4 trials measured blood pressure◦6 trials measured body weight

Compared data from follow-ups of ≤ 6 mos. to follow-ups of up to one yearStatistical significance p-value of

0.01 and 0.1

Results for Blood Results for Blood CholesterolCholesterolRD vs. MD

◦ Random effects analyses= -0.25 mmol/L, (95% CI -0.37, -0.12)*

◦ Equivalent to -9.67 mg/dL decrease

RD vs. self-help resources◦ Random effects analyses= -0.10 mmol/L, 95% CI -

0.22, 0.03◦ Equivalent to -3.87 mg/dL decrease◦ No statistical significance

*statistical significance

Results for Blood Results for Blood CholesterolCholesterolRDs vs. All other groups

◦Random effects= -0.14 mmol/L, (95% CI -0.23, -0.05)*

◦Equivalent to -5.14 mg/dLFollow up 6 mos. or less

compared to one year showed statistical significance for RD vs. self-help but values skewed at beginning of study

Results for Results for HDL-c, Blood Press, HDL-c, Blood Press, BWBWRD vs. Nurse (HDL-c)

◦Random effects = -0.06 mmol/L (95% CI -0.11, -0.01)*

◦Equivalent to 2.3 mg/dL in favor of the nurseRD vs. self-help (Diastolic Blood Press)

◦Random effects = -1.8 mmHg (95% CI -4.4, 0.9)*

RD vs. counselor (Body weight)◦Random effects= -5.8 kg (95% CI -8.91, -

2.69)*◦Equivalent to -12.8 lbs.

Results for LDL-c, Pt. Results for LDL-c, Pt. SatisfactionSatisfactionNo statistical significance found

for the pooled effects of these studies

Studies were not of the best quality to demonstrate a statistical difference

Discussion/ApplicationDiscussion/ApplicationRD vs. MD

◦Overall effect for blood chol was small (< 4%)

◦Most studies were of strong quality but for short duration (< 9 wks.), no evidence of long term effects

◦More time was generally spent with RD than MD which may have accounted for positive result

◦All studies for this group occurred in the U.S. or Canada so generalizability is limited

Discussion/ApplicationDiscussion/ApplicationRD vs. self-help resources

◦Overall effect for blood chol was small (< 2%)◦Quality of studies varied and depended highly

on motivation level of the participant using the self-help leaflet

RD vs. Nurse◦One study showed a statistically significant diff

result in lowering HDL-c in favor of the nurses◦Further studies are warranted for this

comparison because nurses often provide dietary advice because they have more pt. contact

Discussion/ApplicationDiscussion/ApplicationRD vs. Counselor

◦Small study sample but significant result in overall wt. loss for RD group

◦More studies are needed to fully explore the effects of this comparison

Pt. satisfaction◦Future studies should include this as part

of their intervention as it may improve compliance and study quality

Overall there is a need to produce better quality studies making all of these comparisons

Discussion QuestionsDiscussion QuestionsAuthor’s questions

◦For the outcomes assessed, what was the effect of… Type of patient? Setting? Length of follow-up? Intervention was diet-alone or multiple

lifestyle interventions?

Discussion QuestionsDiscussion QuestionsMy questions

◦What were other demographic and environmental factors that could have effected the study results?

◦How did the dietary advice differ per ethnicity and per health condition when comparing RDs and others?

◦What effect would the level of nurse (i.e. ARNP, RN, LVNs) and physician assistants have on dietary advice compared to an RD?

ConclusionConclusion The best way to manage raised blood

cholesterol in the short-term may be for RDs to train all members of the health team to provide appropriate advice.

Use of self-help resources are more cost-effective than individual dietary counseling advice

Patient education should always include maintaining long term behavior change for health sustainability

References References Whitney E, DeBruyne LK, Pinna K, and Rolfes SR. Nutrition for Health and

Health Care. 3rd ed. Thomson Wadsworth Corporation Belmont, CA: Thomsen Learning Inc.; 2007.

Clancy CM. The Promise and Future of Comparative Effectiveness Research. Journal of Nursing Care Quality 2010; 25: 1;1-4.

Neil HA, Brown J. Randomised trial of lipid lowering dietary advice in general practice: the effects on serum lipids, lipoproteins, and antioxidants. BMJ March 1995: 310: 569-573.

Schryver T, Smith C, and Wall M. Participants’ willingness to consume soy foods for lowering cholesterol and receive counseling on cardiovascular disease by a nutrition professional. Public Health Nutrition, 2006; 9:886-874.

Shakiba B. Heterogeneity. Systematic Reviews. http://ssrc.tums.ac.ir/Systematic Review/Heterogeneity.asp. Accessed June 28, 2010.

National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III) Final Report. National Cholesterol Education Program, National Heart, Lung, and Blood Institute- National Institutes of Health. NIH Publication No. 02-5215; September 2002