Patterns and predictors of changes in adherence to highly active antiretroviral therapy: longitudinal study of men and women.

BACKGROUND Adherence to therapy is a dynamic behavior. However, few studies have identified factors associated with changes in adherence to highly active antiretroviral therapy (HAART) among men and women. METHODS From 1999 through 2004, self-reported adherence to HAART was recorded twice yearly as part of 2 prospective cohort studies. At each study visit, participants were categorized as being 100% adherent if they reported full adherence with their HAART regimen over the past 4 days (for men) and 3 days (for women). Repeated-measures logistic regression models were used to identify predictors for changes in adherence between consecutive visits. RESULTS Of the participants, 640 men and 1304 women contributed 2803 and 5972 visit-pairs, respectively. Among white men, the prevalence of 100% adherence decreased from 91% in 1998 to 80% in 2003. Among women and African American men, the prevalence of full adherence was lower (75% and 77% on average, respectively) and stable over time (P>.6). In both cohorts, the presence of clinical symptoms was independently associated with decreasing adherence (odds ratio [OR], 1.38 in men and 1.48 in women). Depression in men (OR, 1.44) and use of alcohol in women (OR, 1.81, 1.52, and 1.29, for binge drinking, moderate-to-heavy drinking, and low consumption, respectively) also predicted decreasing adherence. In addition, the use of drugs by men and women (OR, 0.61 and 0.58, respectively) and alcohol binging by women (OR, 0.41) were negatively associated with improving adherence. CONCLUSIONS Adherence to antiretroviral treatment is a dynamic process; modifiable risk factors are associated with increasing and decreasing adherence, suggesting specific interventions. Moreover, the association of these risk factors with changes in adherence may differ by sex.