Impact of antiretroviral dosing frequency and pill burden on adherence among newly diagnosed, antiretroviral-naive HIV patients.

There are few data on the impact of antiretroviral therapy (ART) regimen factors on adherence in ART-naïve HIV patients on contemporary once- or twice-daily regimens. Ninety-nine newly diagnosed patients in a prospective observational cohort study completed a visual analogue scale to assess their ART adherence. Adherence by type of ART and dosing frequency were compared by Brown-Mood median tests. Participants taking once-daily regimens had higher adherence (n = 70, 99.5%) compared with participants taking twice-daily regimens (n = 29, 94%; P = 0.01). Adherence of participants taking the fixed dose combination efavirenz-emtricitabine-tenofovir (n = 34, 100%) compared with those taking once-daily regimens of two or more pills was no different (n = 36, 99.3%; P = 0.34). Among a cohort of newly diagnosed ART-naïve patients, once-daily dosing of ART resulted in higher adherence than twice-daily dosing. Pill burden among once-daily regimens did not predict adherence, suggesting that factors other than pill burden should drive regimen selection.