Substance use and HIV medication adherence among HIV positive older adults

INTRODUCTION: The CDC estimates that by 2015 more than half of HIV+ persons will be age 50 and older. Older adults have received little attention in HIV research, however, higher rates of alcohol and drug use have been identified. The link between substance use and HIV medication non-adherence is well established in samples of younger adults; this association is less understood among older adults. METHOD: HIV+ men and women over age 50 (n=540) completed telephone surveys that included demographic information, recent (past 30 days) HIV medication adherence, and drug and alcohol use. RESULTS: The majority (76%, n=413) reported substance use. Four use patterns were identified through Latent Class Analysis: 24% (n=99) were primarily marijuana users, 19% (n=79) were primarily crack users, 44% (n=181) were primarily alcohol users, and 13% (n=54) were poly-substance users. Although only 9% of non-users were less than 90% adherent, 40% of users were non-adherent, although adherence did not significantly differ across use patterns. Non-adherence, however, significantly varied with relationship status and substance use pattern. Having an HIV-negative partner was negatively associated with adherence among poly-substance users, but having an HIV+ partner was associated with better adherence among primary marijuana and primary alcohol users. CONCLUSIONS: Substance use is high among HIV+ older adults, and there is a strong relationship with non-adherence. Although being in a relationship is usually a source of social support and associated with positive effects on adherence, among HIV+ older adults who use substances, the associations are more complex.