Measuring Medication Adherence
Are Missed Doses Reported More Accurately Then Perfect Adherence?
Published in: AIDS Care, v. 12, no. 4, 2000, p. 405-408
Posted on RAND.org on December 31, 1999
Self-reports overestimate adherence compared to more objective measures such as electronic monitoring. However, self-report is the most feasible method for clinical settings; therefore, it is important to identify the context in which this method can provide an accurate assessment. To address whether self-reports are more accurate when missed doses are reported, the authors conducted a secondary analysis of data from a methodological study comparing multiple measures of adherence (including self-report and electronic monitoring to a two-week placebo regimen mimicking HAART among 30 HIV-positive patients not on HAART. Results indicated a mean adherence of 85% and 62%, as measured by se4f-report and electronic monitoring respectively. Self-report and electronic monitoring were not significantly correlated in the measurement of proportion of prescribed doses taken among the sub-group of 17 patients who reported missed doses (r = 0. 22), nor among those who reported no missed doses, or the group as a whole. Using electronic monitoring as the validity criterion, these findings indicate that self-reports overestimate adherence even among patients who report missed doses.