Cause of death in people living with HIV who initiated antiretroviral therapy after enrolling to the Thai National AIDS Program from 2008 to 2021

Background Widespread access to antiretroviral therapy (ART) has led to near-normal life expectancies for people living with HIV (PLHIV), shifting the leading cause of death (COD) from AIDS-related to non-AIDS-related mortality. We assessed trends in COD among PLHIV who initiated ART in Thai National AIDS Program (NAP). Methods We analysed NAP data from PLHIV aged >= 15 at ART initiation, who started ART under Thailand's universal health coverage from 2008 to 2021. Individual data was linked with the National Death Registration system, and a rule-based algorithm applied text mining to classify COD as AIDS-related, non-AIDS-related and uncertain. Competing risk models examined associations between demographic and clinical characteristics and COD. Standardized mortality ratios (SMR) were calculated using mortality rate from the general Thai population. Findings Among 398,182 PLHIV (37.1% females) enrolled, the median (IQR) age was 35 (28-43) years, 43.6% commenced ART with CD4 counts <200 cells/mm3. Over 2,631,435 person years of follow-up, 73,768 (18.5%) deaths occurred: 56% AIDS-related, 40% non-AIDS-related and 4% uncertain. The cumulative incidence of AIDS-related mortality at 14 years was 14.74%, non-AIDS-related 12.04% and all-cause mortality 27.93%. AIDS-related deaths declined from 60% to 50% over the study period. Low CD4 counts, permanently loss to care and treatment at non-capital city were significantly associated with higher AIDS-related mortality. The SMR was higher in females [9.08 (95% CI 8.97-9.20] compared to males [5.83 (95% CI 5.78-5.88). Interpretation AIDS-related mortality decreased over time, but continued efforts are needed to improve earlier diagnosis, and equitable outcomes for women and those residing outside major cities.