Association Between ART Initiation Timing and Treatment Outcomes in Older People Living With HIV: A Longitudinal Study from Baise, China

Background: The number of new HIV diagnoses among older people living with HIV (PLWH) is increasing in China. This population often faces delayed diagnosis, advanced disease, and polypharmacy, posing challenges for antiretroviral therapy (ART) management. Objectives: To evaluate the impact of ART initiation timing—based on baseline CD4+ T-cell count—on viral suppression, immune recovery, survival, and severe adverse drug reactions (SADRs) among older PLWH aged ≥50 years in Baise, Guangxi, under the “Test and Treat” strategy. We further aimed to identify factors associated with treatment outcomes to inform individualized management. Methods: This retrospective cohort study included 1,802 older people living with HIV (PLWH) aged ≥50 years who initiated antiretroviral therapy (ART) for the first time between January 2017 and June 2022 in Baise, Guangxi. Participants were categorized by baseline CD4+ T-cell count into delayed initiation (<350 cells/μL), standard initiation (350–500 cells/μL), and early initiation (>500 cells/μL). Generalized estimating equations (GEE) were used to assess viral suppression and CD4+ T-cell recovery over time. The Weibull accelerated failure time (AFT) model was applied to estimate time to all-cause mortality. Multivariable logistic regression was used to identify factors associated with severe adverse drug reactions (SADRs). Adjusted models accounted for age, gender, marital status, ethnicity, education level, and ART regimen. Results: Only 9.2% of older people living with HIV (PLWH) initiated ART early (>500 cells/μL), while 74.7% started in late HIV infection (≤350 cells/μL). There was no significant difference in viral suppression by treatment group. The early treatment group achieved significantly better CD4+ T-cell recovery compared to the other two groups (P < 0.001). The delayed treatment group had significantly shorter survival than the early treatment group (time ratio [TR] = 0.33, 95% CI: 0.14–0.78), but no significant survival difference was observed between the early and conventional treatment groups. Overall, 25.0% of participants experienced severe adverse drug reactions (SADRs); SADR incidence did not differ by treatment group. However, the 3TC+AZT+EFV regimen was associated with a higher risk of SADR than 3TC+TDF+EFV (adjusted odds ratio [aOR] = 3.50, 95% CI: 2.57–4.76). Women had better viral suppression and CD4+ T-cell recovery. Marital status, ethnicity, and ART regimen were also associated with survival outcomes. Conclusion： The implementation of China’s “Test and Treat” strategy has not met expectations. ART initiation timing did not affect viral suppression or SADR risk; however, delayed initiation impaired immune recovery and increased mortality risk. Clinically, ART should be initiated as early as possible for older PLWH, and individualized strategies should be developed based on their characteristics to optimize treatment outcomes.