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The Measurement of Antiretroviral Adherence in HIV. Sharon Mannheimer, MD Harlem Hospital / Columbia University Treatment Adherence Services Quality Learning Network meeting May 3, 2007. Overview. Background on Adherence in HIV Adherence Measurement CASE Adherence Index - PowerPoint PPT Presentation
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The Measurement of Antiretroviral Adherence in HIV
Sharon Mannheimer, MD
Harlem Hospital / Columbia University
Treatment Adherence Services Quality Learning Network meeting
May 3, 2007
Overview
• Background on Adherence in HIV
• Adherence Measurement
• CASE Adherence Index
• Other Self-Report Measures
Importance of Adherence
Nonadherence associated with:
• Virologic failure
• Worse immunologic (CD4) outcomes
• Higher Hospitalization rates
• OIs / HIV disease progression
• Increased Mortality• Resistance (at some adherence levels)
Survival vs. Adherence
Progression to death among 847 initially ART-naïve HIV+ subjects with >12 mos. follow-up; adherence > 75% (circles) vs. adherence <75% (squares). Hogg, et al. AIDS 2002,16:1051-8.
How much adherence is enough?
Adherence to Antiretroviral Therapy and Virologic Failure
Paterson, Annals of Internal Medicine, 2000
0
20
40
60
80
100
% with virologic
failure
Adherence (by MEMS) significantly associated with virologic failure (P<0.001)
Adherence, %>95 90-94.9 80-89.9 70-79.9 <70
21.7
54.6
66.771.4
82.1
Adherence MeasurementAdherence Measurement
– No “gold standard”– Many methods are impractical in clinical
settings– Simple measures predictive of HIV
outcomes would be valuable
Classification of Adherence Measures:
• Direct
or
• Indirect
Direct Measures of Adherence:
• direct observation
• measuring levels of the drug in body fluids (“Therapeutic Drug Monitoring”)
• biologic markers
• monitoring clinic attendance
Indirect Measures of Adherence:
• self-report
• provider assessment
• electronic monitoring devices (MEMS)
• pill count
• medication refill rate (pharmacy)
• monitoring for an expected therapeutic outcome
Direct vs. Indirect Measures:
• In general, direct measures are more objective and yield more reliable assessments of adherence
• each method has limitations
Problems with direct measures:• Direct observation: usually not practical
• Therapeutic drug monitoring: costly, inconvenient, not widely available, reflects recent adherence only
• Biologic marker (e.g. HIV viral load): may not correlate 100% with adherence, factors other than adherence could effect marker
• Clinic attendance: does not necessarily correlate with medication adherence
Problems with indirect measures:• Self report: can overestimate adherence• Provider assessment: physicians poor at
predicting adherent behavior• Electronic monitoring devices (e.g. MEMS
caps): costly, bulky, for only 1 drug, measures only opening, interferes with pillbox use, inaccuracies can occur with improper use (e.g., pocketing doses)
• Pill count: ”pill dumping,” patient can forget to bring bottles, does not assess timing
• Refill rate: only practical if patients use same pharmacy, not 100% correlation
Benefits of Self-Report
• Easy to administer• Inexpensive• May reveal reasons for missed doses• Self-report of nonadherence very
reliable• Adherence measured by self-report
correlates with HIV laboratory and clinical outcomes
Self-Report Methods
• No gold standard• AACTG 3- or 4-day self-report format widely
used– Day-by-day, dose-by-dose recall of each ART
med. Over prior 3 or 4 days
• Other simpler formats available:– CPCRA 7-day self-report– Visual Analog Scale– CASE Adherence Index
The Case Adherence Index QuestionnaireThe Case Adherence Index QuestionnairePlease ask each question and circle the corresponding number next to the answer, then add up the numbers circled to calculate Index score.1. How often do you feel that you have difficulty taking your HIV medications on time? By “on time” we mean no more than two hours before or two hours after the time your doctor told you to take it. 4 Never
3 Rarely 2 Most of the time 1 All of the time
2. On average, how many days PER WEEK would you say that you missed at least one dose of your HIV medications?
1 Everyday2 4-6 days/week3 2-3 days/week4 Once a week5 Less than once a week6 Never
3.When was the last time you missed at least one dose of you HIV medications?
1 Within the past week2 1-2 weeks ago3 3-4 weeks ago4 Between 1 and 3 months ago5 More than 3 months ago6 Never
INDEX SCORE: ______ (> 10 = good adherence, < 10 = poor adherence)
Development of CASE Index
• Developed during a large Health Resources and Services Administration (HRSA)-funded evaluation study (1999-2003) of 12 US adherence support programs– Special Projects of National Significance (SPNS)
• Cross-site evaluation coordinated by the New York Academy of Medicine’s (NYAM) Center for Adherence Support Evaluation (CASE)
CASE Cross-Site Evaluation
• CASE insured uniform data collection:– Standardized core data elements– Uniform Instrument– Central interviewer and chart abstractor training– Uniform measurement periods
• Adherence questions:– Individual questions about adherence behavior – AACTG 3-day self-report
Adherence Intervention & Evaluation SitesAdherence Intervention & Evaluation Sites
Health Services Center, Inc., Hobson City, ALHealth Services Center, Inc., Hobson City, AL Chase Brexton Health Services, Inc., Baltimore, MDChase Brexton Health Services, Inc., Baltimore, MD Dimock Community Health Center, Roxbury, MADimock Community Health Center, Roxbury, MA Harlem Hospital Center, New York, NYHarlem Hospital Center, New York, NY Helena Hatch Special Care Center, Washington University, Helena Hatch Special Care Center, Washington University,
St. Louis, MOSt. Louis, MO Johns Hopkins University School of Medicine, Baltimore, Johns Hopkins University School of Medicine, Baltimore,
MDMD Mission Neighborhood Health Center, San Francisco, CAMission Neighborhood Health Center, San Francisco, CA Multnomah County Health Department, Portland, ORMultnomah County Health Department, Portland, OR SUNY Downstate Medical Center, Brooklyn, NYSUNY Downstate Medical Center, Brooklyn, NY St. Luke's Roosevelt Hospital Center, New York, NYSt. Luke's Roosevelt Hospital Center, New York, NY North Broward Hospital District, Ft. Lauderdale, FLNorth Broward Hospital District, Ft. Lauderdale, FL Urban Health Study, San Francisco, CAUrban Health Study, San Francisco, CA
Participants in Adherence Analysis
• 1,154 participants in HRSA/SPNS cross-site study: – enrolled between July 1, 2000 and July 1, 2003
• 524 cases included in adherence analyses:– Had at least 1 follow-up
– On ART at baseline and follow-up– had corresponding CD4 and HIV RNA data at the
first 3-month follow-up
Participant Characteristics%
Gender
Male 65
Female 34
Transgender 1
Race/Ethnicity
African American 66
Latino 5
White 26
Education
Not high school graduate 41
High school graduate or GED 36
Some college/technical school 23
Mean age, years 40.13 (SD = 8.6)
Participant Characteristics - 2%
Self-reported HIV risk behavior
Men reporting sex with men (MSM) 29
Injecting drug use 16
MSM and injected drugs 2
Heterosexual contact 45
Heterosexual contact and injected drugs
3
Blood transfusion, blood components, or tissue
3
Other 2
Mean CD4 count, cells/mm3(SD) 256 (251)
Median CD4 count, cells/mm3 193
Mean log10 HIV RNA level (SD) 3.99 (1.35)
Analysis of HRSA/SPNS Cross-Site Adherence Data:
Development of the CASE Index
• Principal component analysis performed:– Responses to 3 adherence questions
explained 69% of total variation in adherence, higher than any other combination of questions
– Responses to each of the 3 CASE questions carried approximately equal importance
Mannheimer, et al. AIDS Care 2006;18:853-861.
The Case Adherence IndexThe Case Adherence Index
3 adherence questions:– 1. Frequency of “difficulty taking HIV medication on
time (no more than two hours before or two hours after the time your doctor told you to take it)” –
• Response options: Never, Rarely, Most of the time, or All of the time
– 2. frequency of “average number of days per week at least one dose of HIV medications was missed”
• Response options: Everyday, 4-6 days per week, 2-3 days per week, Once a week, Less than once a week, or Never
– 3. “Last time missed at least one dose of HIV medications”
• Response options: Within the past week, 1-2 weeks ago, 3-4 weeks ago, 1 to 3 months ago, More than 3 months ago, or Never
The Case Adherence Index – The Case Adherence Index – Statistics / ScoringStatistics / Scoring
• Responses coded: – For #1 (reverse coded) - possible range of 1 to 4
points – For #2 and #3 - possible range of 1 to 6 points
• Composite score obtained by adding responses: – Range 3 to 16 – Higher scores indicate better adherence
The Case Adherence Index QuestionnaireThe Case Adherence Index QuestionnairePlease ask each question and circle the corresponding number next to the answer, then add up the numbers circled to calculate Index score.1. How often do you feel that you have difficulty taking your HIV medications on time? By “on time” we mean no more than two hours before or two hours after the time your doctor told you to take it. 4 Never
3 Rarely 2 Most of the time 1 All of the time
2. On average, how many days PER WEEK would you say that you missed at least one dose of your HIV medications?
1 Everyday2 4-6 days/week3 2-3 days/week4 Once a week5 Less than once a week6 Never
3.When was the last time you missed at least one dose of you HIV medications?
1 Within the past week2 1-2 weeks ago3 3-4 weeks ago4 Between 1 and 3 months ago5 More than 3 months ago6 Never
INDEX SCORE: ______ (> 10 = good adherence, < 10 = poor adherence)
CASE Index Compared to CASE Index Compared to AACTG 3-day Self ReportAACTG 3-day Self Report
• CASE Index’s sensitivity and specificity relative to 3-day self-report at cut-off of ≥ 95% was calculated
• Based on the analysis, CASE Index was recoded as a dichotomy where: – CASE Index scores > 10 indicated high adherence– CASE Index scores ≤ 10 indicated low adherence
Sensitivity and Specificity of CASE Adherence Index
vs. 3-day recall adherence self-report
CASE Index Score Sensitivity (%) Specificity (%)
5 99.28 8.00
6 98.32 18.00
7 96.64 30.00
8 92.57 52.00
9 84.65 77.00
1010 74.1074.10 99.0099.0011 62.83 99.00
12 55.64 100.00
13 48.20 100.00
14 38.61 100.00
15 25.42 100.00
CASE Index Concurrent Validity CASE Index Concurrent Validity with 3-day Self Reportwith 3-day Self Report
• Logistic regression showed strong correlation:– Odds of 3-day self-report > 95% was at least 60 times more
for patients with a CASE Index score > 10 compared to those with a CASE Index score ≤ 10 (p < 0.001) across four serial cross-section follow-up periods (3, 6, 9 and 12 months after enrollment)
• Receiver Operating Characteristic Curves (ROC) showed a very strong association between 3-day self-report at 95% and CASE Adherence Index Scores (>10 vs. < 10) across the four measurement quarters
Mannheimer, et al. AIDS Care 2006;18:853-861.
Relationships between Relationships between Self-reported Adherence Measures and HIV RNASelf-reported Adherence Measures and HIV RNA
• CASE Adherence Index was strongly associated with:– a 1 log decrease in HIV RNA levels (p ≤ 0.05)– achieving HIV RNA < 400 copies/ml (p ≤ 0.05)
• Association between 3-day self-report with HIV RNA was not as strong: – significance for a 1-log decrease from baseline
HIV only at 6-month follow-up – significance for HIV < 400 copies/ml also only at
6-month follow-up
Relationship between Self-reported Adherence Relationship between Self-reported Adherence and HIV RNAand HIV RNA
Adherence Measure Comparison
HIV RNAMeasure
Odds ratio estimates
3 Months 6 Months 9 Months 12 Months
3-Day Self-Report
> 95%vs. ≤
95%
1-log Decrease
1.23 2.26** 1.53 1.16
HIV RNA < 400
0.97 2.30** 1.66* 1.23
CASEAdherence
Index
> 10vs. ≤ 10
1-log Decrease
1.52* 1.90** 1.76** 2.13**
HIV RNA < 400
1.60** 1.68** 1.87** 1.60*
Note: * p < 0.10 ** p < 0.05
Relationships between Relationships between Self-reported Adherence Measures Self-reported Adherence Measures
and CD4 Land CD4 Lymphocyte Counts Counts
• A significant relationship between CASE Adherence Index and changes in CD4 lymphocyte counts from baseline only at 12 months
• There were no observed relationships between changes in CD4 and 3-day self-report
Limitations of HRSA/SPNS dataLimitations of HRSA/SPNS data• Only 524 of 1,154 individuals in local sites’
adherence programs were included in adherence analyses
• ART Naive and ART experienced but not currently receiving ART were excluded from the analyses
• High attrition rates• Social desirability of self-report• Adherence instruments administered in same
interview• Only self-reported adherence
CASE Index SummaryCASE Index Summary
• a new measure of self-reported ART adherence
• easy to administer and score
• high degree of sensitivity and specificity with the 3-day self-report (concurrent validity)
• a better predictor of HIV RNA changes over time than 3-day self-report
Other Self-Report Methods
• AACTG 3- or 4- day recall
• CPCRA 7-day recall
• Visual Analog Scale
AACTG 3-day recall
CPCRA 7-day recall
Virologic Outcome by Adherence*in two CPCRA Antiretroviral Trials
Mannheimer, et al. CID 2002
0
10
20
30
40
50
60
70
80
100%
80-99%
0-79%
% HIV RNA <50 copies/ml
) (n=922) (n=699) (n=531)Month 1 (n=1074)
Month 4 Month 8 Month 12
P < 0.005 for difference between categories at months 4,8,12*by adherence self-report C•P•C•R•A
Immunologic Outcome by Adherence*in two CPCRA Antiretroviral Trials
Mannheimer, et al. CID 2002
10
30
50
70
90
110
130
150
170
190
100%
80-99%
0-79%
Change in CD4 (cells/mm3) from baseline
(n=1074) (n=922) (n=699) (n=531)Month 1 Month 4 Month 8 Month 12
P < 0.05 for difference between categories at months 4,8,12 *by adherence self-report C•P•C•R•A
Visual Analog Scale
“Put a cross on the line below at the point showing your best guess about how much medication you have taken in the last month.
We would be surprised if this was 100% for most people, e.g. 0% means you have taken no medication; 50% means you have taken half your medication; 100% means you have taken every single dose of medication.”
_______________________________________________0 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
Walsh AIDS 2002, 16:269-277; Oyugi JAIDS 2004;36:1100–1102
Summary
• Adherence critical for successful HIV treatment
• Many methods available for measuring adherence
• CASE Index – easy to administer and score – correlates with HIV RNA outcomes