Self-efficacy as a mediator of patient navigation interventions to engage persons living with HIV and substance use

Background: People living with HIV who report substance use (PLWH-SU) face many barriers to care, resulting in an increased risk for poor health outcomes and the potential for ongoing disease transmission. This study evaluates the mechanisms by which Patient Navigation (PN) and Contingency Management (CM) interventions may work to address barriers to care and improve HIV outcomes in this population. Methods: Mediation analysis was conducted using data from a randomized, multi-site trial testing PN interventions to improve HIV care outcomes among 801 hospitalized PLHW-SU. Direct and indirect effects of PN and PN + CM were evaluated through five potential mediators—psychosocial conditions, healthcare avoidance, financial hardship, system barriers, and self-efficacy for HIV treatment adherence—on engagement in HIV care and viral suppression. Results: The PN + CM intervention had an indirect effect on improving engagement in HIV care at 6 months by increasing self-efficacy for HIV treatment adherence (β = 0.042, 95% CI = 0.008, 0.086). PN + CM also led to increases in viral suppression at 6 months (β = 0.090, 95% CI = 0.023, 0.168) and 12 months (β = 0.069, 95% CI = 0.009, 0.129) via increases in self-efficacy, although the direct effects were not significant. No mediating effects were observed for PN alone. Conclusion: PN + CM interventions for PLWH-SU can increase an individual's self-efficacy for HIV treatment adherence, which in turn improves engagement in care at 6 months and may contribute to viral suppression over 12 months. Building self-efficacy may be a key factor in the success of such interventions and should be considered as a primary goal of PN + CM in practice.