Correlation between self-reported adherence to highly active antiretroviral therapy (HAART) and virologic outcome

The Patient Medication Adherence Questionnaire Version 1.0 (PMAQ-V1.0) is a patient-reported adherence instrument to assess medication-taking behavior s and identify barriers to adherence with antiretroviral therapy. To assess the correlation between adherence and virologic outcome, the PMAQ-V1.0 was administered to 194 antiretroviral-experienced adults with HIV infection e nrolled in a 16-week evaluation of protease inhibitor-containing regimens f eaturing a lamivudine/zidovudine combination tablet. At baseline, plasma HI V-1 RNA levels were less than 10,000 copies/mL and CD4+-cell counts were eq ual to or greater than 300 x 10(6)/L; patients had been receiving a convent ional regimen of lamivudine + zidovudine (separately) plus a protease inhib itor for at least 10 weeks immediately prior to the study. Forty-eight perc ent of patients who reported missing at least one dose of a nucleoside reve rse-transcriptase inhibitor (NRTI) during the study had detectable plasma H IV-1 RNA, compared with 26% of patients who reported no missed doses (P=.00 2). Patients who missed at least one dose of an NRTI or protease inhibitor were 2.5 times more likely to have quantifiable HIV-1 RNA than those who re ported no missed doses. Patients who reported fewer barriers and more motiv ators to adherence had better virologic outcomes (P=.001). Several dimensio ns of the PMAQ-V1.0 did not function as well as hypothesized. In this study , self-reported adherence derived from the PMAQ-V1.0 predicted virologic ou tcomes, but further refinement of the dimensions appears warranted.