Measuring Adherence Jonathan Shuter, M.D. Treatment Adherence Network Meeting 2/27/01.
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Transcript of Measuring Adherence Jonathan Shuter, M.D. Treatment Adherence Network Meeting 2/27/01.
Measuring Adherence
Jonathan Shuter, M.D.
Treatment Adherence Network Meeting 2/27/01
Measuring Adherence--One Extreme
• “I firmly believe that if the whole materia medica as now used could be sunk to the bottom of the sea, it would be all the better for mankind--and all the worse for the fishes.”
1860: Oliver Wendell Holmes to the Massachusetts Medical Society
Measuring Adherence--The Other Extreme
D.O.T.
Measuring Adherence--The Middle Ground
• Methods that quantify missed and taken doses
• Methods that measure physiologic effects
• Methods that assess systemic blood levels of drug
Self-Report
• Cheap• Correlated with
virologic outcomes (report of non-adherence is more reliable than report of adherence)
• Overestimates adherence
Pro’s Con’s
Clinician-Estimated Adherence
• Cheap • Most poorly correlated of all measures with actual adherence
Pro’s Con’s
PROVIDERS ARE TERRIBLE JUDGES OF ACTUAL ADHERENCE AND OF THEIR PATIENTS’ ABILITY TO ADHERE!
Pill Counts
• Cheap• Useful adjunct to self-
report
• Overestimates adherence– “Pill dumping”
• Time consuming• Casts provider in role
of medication monitor, not ally/advocate
Pro’s Con’s
Pharmacy Records
• Cheap• Useful adjunct to self-
report
• Cannot stand alone as adherence measurement method– One patient may use many
pharmacies
– Picking up prescriptions does not equate with taking medications
– Patients may have other sources of medications
Pro’s Con’s
Electronic Monitoring
• Best correlation with virologic outcomes
• Data is available in a computer accessible format
• Allows more detailed view of non-adherence patterns (weekends, nighttime, etc.)
• Expensive• Poor patient acceptance• Not infallible (patients can
open bottle and not take pill)
• Not compatible with pillbox
• Usually only measures one medication
Pro’s Con’s
Measuring Adherence--The Middle Ground
• Methods that quantify missed and taken doses
• Methods that measure physiologic effects
• Methods that assess systemic blood levels of drug
Indirect Laboratory Markers
• AZT=========> Increased MCV
• ddI==========> Increased uric acid
• Indinavir======> Increased bilirubin
Laboratory Markers
• Viral load
• CD4
• Genotypic/phenotypic resistance
Measuring Adherence--The Middle Ground
• Methods that quantify missed and taken doses
• Methods that measure physiologic effects
• Methods that assess systemic blood levels of drug
Plasma Levels
• Correlates with virologic outcomes
• Only method that ensures that the patient actually ingested the drug
• May allow insight into absorption or drug interaction problems
• Very expensive• Levels are extremely
variable• Only provides information
about the last dose
Pro’s Con’s
Montefiore Data
020406080
100120140
Nev
er
Rar
ely
Som
etim
es
Oft
en
Alw
ays
How often do you miss doses of your HIV medications?
Montefiore Data
• 30/106 (28.3%) patients prescribed ART responded “Never” [miss medications], every time they were interviewed.
• These patients are not distinguished by any specific characteristic measured in the study. There are trends toward underrepresentation of females and IDUs in this group.
• Analyzed variables include age, gender, ethnicity, HIV risk behavior, AIDS, adverse effects, and depression score.
Conclusions
• There is no perfect method or combination of methods available to measure adherence
• Nevertheless, numerous methods of measurement correlate with virologic outcomes, and thus provide useful information
• Some method of adherence measurement should be used for all patients, but decisions regarding which method/s should be individualized
For more HIV-related resources, please visit www.hivguidelines.org