Patient-reported nonadherence to HAART is related to protease inhibitor levels

Objective: To compare self-reported nonadherence with antiretroviral therap y (ART) with predose plasma levels of protease inhibitor (PI). Design: A cross-sectional study of consecutive patients from a university-b ased HIV clinic in Pome, Italy, was conducted. One hundred and forty HIV-in fected patients were prescribed regimens containing ritonavir or indinavir. A patient questionnaire assessing knowledge of treatment regimen, adherenc e behavior, reasons for taking and missing therapy, factors influencing adh erence, and health behaviors was administered. A predose PI plasma level wa s measured concurrently. Results: By patient report, 12% missed at least one dose "yesterday," and 2 4% missed doses in the last 3 days; 14% had a predose plasma concentration below the assay limit of quantitation (2 ritonavir and 18 indinavir samples ). Confusion, poor psychological well-being, longs office wait, running out of drugs between visits, having relatives to remind the patient to take me dication, children, and alteration of sense of taste were related to unquan tifiable predose levels of PI. In multivariable analysis, reported nonadher ence (odds ratio [OR], 15.8; 95% confidence interval [CI], 4.0-63.3) and co nfusion (OR, 9.9; 95% CI, 1.4-69.6) were related to unquantifiable predose levels of PI. Conclusion: Self-report of missing a dose of antiretroviral medication "yes terday" was related to an unmeasurable plasma PI level.