Purpose: To assess factors associated with adherence, particularly pill burden, to combination antiretroviral therapy (cART) using multivariate models.
Method: A cross-sectional survey of US adults with a self-reported diagnosis of HIV/AIDS was conducted between April and May 2007. Respondents on a cART regimen of at least 2 nucleoside reverse transcriptase inhibitors plus at least 1 protease inhibitor or non-nucleoside reverse transcriptase inhibitor (n = 461) were included in the analytic sample. Multiple logistic regression models determined independent predictors of complete adherence (defined as never missing or skipping an antiretroviral dose).
Results: Fifty-four percent of respondents reported complete adherence to cART. Adherent respondents reported a lower percentage of hospitalizations (11% vs 28%; P < .0001) and emergency room visits (26% vs 34%; P < .09). Respondents taking the single tablet efavirenz/emtricitabine/tenofovir fixed-dose regimen were significantly more likely to have complete adherence than respondents taking other cART regimens (odds ratio [OR] 2.1, P < .05), and higher imputed daily HIV pill count was associated with lower likelihood of complete adherence (OR 0.93, P < .05).
Conclusion: This study shows the negative impact of higher pill burden on medication adherence, an important factor associated with treatment outcomes in patients with HIV/AIDS.