Number of daily pills, dosing schedule, self-reported adherence and health status in 2010: a large cross-sectional study of HIV-infected patients on antiretroviral therapy.

OBJECTIVES: The aim of the study was to assess whether pill burden is associated with self-reported adherence to current combination antiretroviral regimens and health status in a large sample of unselected and chronically treated HIV-infected patients.
METHODS: An adherence and health status questionnaire was offered to all patients collecting their drugs between March and May 2010 at our clinic; both parameters were primarily evaluated using a visual analogue scale. Linear correlations were evaluated using Spearman's correlation coefficient. Wilcoxon's rank-sum test and the χ(2) test were used to compare quantitative and qualitative variables. The generalized linear model was used in multivariable analyses.
RESULTS: Among 2763 subjects on treatment during the study period, 2114 (78.8% male; mean age 46.9 ± 8.84 years) were tested for adherence; 1803 (85.3%) had viral loads < 50 HIV-1 RNA copies/mL. After adjusting for age, gender, HIV risk factor, current CD4 count, pill burden and dosing interval, adherence was higher in patients with undetectable HIV RNA (P < 0.0001) and directly associated with current CD4 count (P = 0.029). After adjusting for the same variables, health status was better in patients with undetectable viraemia (P = 0.004) and in men who have sex with men (MSM) and heterosexuals compared with injecting drug users and those with other risk factors (P < 0.0001 for MSM and P = 0.008 for heterosexuals); it was also directly associated with current CD4 count (P < 0.0001) and inversely associated with age (P < 0.0001) and pill burden (P = 0.019).
CONCLUSIONS: In this highly adherent population, the number of daily pills was related to self-reported health status but not to self-reported adherence, whereas the dosing interval did not influence self-reported adherence or health status.