Assessing the effects of a novel intervention for antiretroviral medication adherence

Abstract

The use of antiretroviral therapy (ART) has led to substantial declines in morbidity and mortality in patients with HIV, however the benefits of ART are largely dependent on strict adherence. Effective interventions have been developed to improve adherence that include the use of cognitive behavioral treatment techniques or external supports such as modified directly observed therapy (mDOT). Project MOTIV8 assessed whether a novel intervention combining motivational interviewing based cognitive behavioral therapy (MI-CBT) counseling with modified directly observed therapy (mDOT) was more effective than MI-CBT counseling alone or standard care (SC) for increasing ART adherence (Goggin et al., 2013). The results demonstrated an interaction effect such that the combined MI-CBT/mDOT group had its greatest effect at week 12 of the intervention, and then adherence rates declined more rapidly than the SC and MI-CBT groups as the intervention concluded. The aim of this study was to enhance our understanding of the intervention effects found in Project MOTIV8 by identifying how mediator variables were impacted by treatment throughout the course of the study. Treatment was based primarily on the Information-Motivation-Behavioral Skills Model and included variables that measured participants’ adherence information (knowledge about ART), adherence motivation (personal and perceptions of significant others’ attitudes and beliefs that impact patients’ motivation), and adherence behavioral skills (e.g., acquiring medications and social support for adherence). Data for this secondary data analysis comes from Project MOTIV8 and was collected at baseline, week 24, and week 48. Participants were recruited from six outpatient clinics and stratified by ART experience and clinic. Data from 204 participants were available for analysis. Participants were on average 40 years old, 76% were male, and 57% were African American. A total of 14 mediator variables were measured throughout the course of the intervention. A principal components analysis (PCA) was used to reduce the number of variables and structural equation modeling (SEM) was used to determine which mediator variables were impacted by treatment and which mediator variables predicted adherence. The results of the PCA identified three latent IMB constructs which included 11 of the 14 mediator variables. The results of a SEM analysis revealed that mDOT significantly decreased participants’ adherence information and increased adherence motivation at the end of treatment. However these effects weren’t found during the 6-month follow-up. There were no significant effects found between MI-CBT and any of the IMB constructs. Only adherence motivation had a significant positive effect on adherence at the 6-month follow-up. These findings provide direction for improving treatment and advancing treatment research.