OBJECTIVE: The aim of the study was to determine how well self-reported adherence fares compared to therapeutic drug monitoring in monitoring HAART adherence.
METHODS: We administered a validated self-reported adherence (SRA) questionnaire to 925 HIV patients on HAART in a large Malaysian hospital from 2010 to 11. We also performed Therapeutic Drug monitoring (TDM) by concurrently collecting and testing blood samples for Efavirenz, Nevirapine and Lamivudine using Liquid Chromatography/Mass Spectrometry. We compared the SRA against the TDM results. Sensitivity, specificity, positive (PPV) and negative predictive (NPV) and diagnostic accuracy values were computed for each drug.
RESULTS: Self-reported adherence (SRA) over-estimates adherence by between 6 and 10percentage points compared to therapeutic drug monitoring (TDM). SRA is highly sensitive with sensitivity exceeding 0.90 but is not very specific (0.56-0.63). PPV for SRA ranged between 0.76 (Lamivudine) and 0.84 (Efavirenz) while NPV ranged between 0.78 (Lamivudine) and 0.81 (Efavirenz). Overall diagnostic accuracy ranged between 0.76 (Lamivudine) and 0.84 (Nevirapine).
CONCLUSION: Self-reported adherence is a surprisingly accurate instrument for measuring HAART adherence compared to TDM and can be reliably used in practice in resource-poor settings. Copyright © 2013 Elsevier Inc. All rights reserved.