Impact of COVID-19 pandemic on treatment outcomes among people living with HIV in Thailand: A nested case-control study

Background: The COVID-19 pandemic disrupted global healthcare systems, significantly affecting HIV service delivery and outcomes. This study evaluated the pandemic’s impact on HIV care among people living with HIV (PLWH). Methods: A nested case-control study was conducted within a cohort of PLWH attending an infectious disease clinic. Participants were included if medical records were available from January 2021 to December 2022. The primary outcome was achieving an undetectable HIV viral load. Participants were categorized into “missed appointment” and “non-missed appointment” groups. Results: Among 615 PLWH, 304 were in the missed appointment group and 311 in the non-missed group. Those who missed appointments were younger (mean age 46 vs. 49 years, p < 0.001) and had a higher prevalence of opportunistic infections (47% vs. 36%, p < 0.001). They also reported more missed antiretroviral doses (5.3% vs. 0%, p < 0.001), greater reliance on telemedicine (17.4% vs. 4.5%, p < 0.001), and greater impacts from COVID-19 on healthcare access, family circumstances, daily activities, and finances (p < 0.001). Post-pandemic, this group had a lower rate of viral suppression (92.4% vs. 97.1%, p = 0.009), although no significant difference was observed in opportunistic infection incidence (1.7% vs. 0.3%, p = 0.089). Factors associated with missed appointments included prior opportunistic infections (OR 2.04, 95% CI 1.42–2.92), reduced healthcare accessibility (OR 3.32, 95% CI 2.18–5.04), family-related challenges (OR 1.97, 95% CI 1.37–2.84), and telemedicine use (OR 3.65, 95% CI 1.88–7.09). Older age was associated with fewer missed appointments (OR 0.80, 95% CI 0.69–0.93). Conclusions: The COVID-19 pandemic disrupted HIV care in Thailand, leading to reduced viral suppression, particularly among younger individuals and those with prior opportunistic infections. Adaptive strategies are needed to maintain continuity of HIV care during public health crises.