The temporal relationship between alcohol consumption and HIV-medication adherence: a multilevel model of direct and moderating effects

Previous studies documenting an association between alcohol use and HIV medication nonadherence, have been unable to distinguish between-persons characteristics from within-person characteristics representing the temporally linked effects of alcohol. Hierarchical Linear Modeling (HLM) explored within- and between-person predictors of adherence during the past 14 days, as well as factors that moderate the event-level effects of alcohol consumption among 272 HIV-positive men and women with alcohol problems. On days in which participants drank, they had almost 9 times higher odds of medication nonadherence, with each drink increasing the odds by 20%. The cognitive and alcohol factors had significant between-person effects on adherence. Individuals with strong and rigid beliefs about the importance of strict medication adherence were significantly more affected by each dose of alcohol, while individuals with more alcohol use and problems were less affected by each drink. Regimen complexity increased the effects of having 1 or more drinks. These results highlight the importance of promoting medication adherence among alcohol-using adults, especially among patients with complex regimens or with high confidence and positive attitudes toward HIV medication.