Healthcare utilisation in people living with HIV: the role of substance use, mood/anxiety disorders and unsustained viral suppression - a retrospective cohort study in British Columbia, Canada, 2001-2019

Objective People living with HIV (PLWH) are disproportionately affected by substance use disorder (SUD) and mood/anxiety disorders, which are barriers to sustained viral suppression and can contribute to increased healthcare utilisations. This study examined the impact of SUD and mood/anxiety disorders on healthcare utilisation of PLWH with sustained and unsustained viral suppression. Design and participants This retrospective population-based cohort study used administrative data from 9757 antiretroviral-treated PLWH (83% men, median age 40 years). Eligible PLWH were >= 19 years of age, followed during 2001-2019, and achieved viral suppression at least once during follow-up. Setting This study was conducted in British Columbia, Canada. Measurements The exposure variable consisted of eight levels and included (1) sustained suppression, (2) SUD and mood/anxiety disorder diagnoses and the interaction between (1) and (2). Outcome variables included annual counts of primary care and specialist physician visits, laboratory visits, acute care hospitalisation, day surgery episodes and hospital length of stay (LOS). Statistical count models were used to determine the effect of exposure variables on each healthcare utilisation outcome while adjusting for socioeconomic confounders. Results In the presence of sustained suppression, having both disorders was significantly associated with over four times more acute-care hospitalisations (0.28 vs 0.05), three times longer LOS (9.1 vs 3.0 days) and almost double primary care physician (13.1 vs 6.9) and specialist (7.9 vs 4.0) visits. Overall, SUD alone was associated with increased use of all healthcare services (except day surgery). Regardless of disorder diagnoses, unsustained suppression was associated with higher healthcare utilisation (except day surgery). Conclusion In this study, SUD, mood/anxiety disorders and unsustained suppression, when combined, resulted in the highest healthcare utilisation among PLWH. The results suggest that providing comprehensive mental health and substance use services to PLWH and addressing barriers to sustained suppression could reduce the healthcare burden within this population.