Longitudinal trends in mortality and its causes among migrant HIV/AIDS patients undergoing antiretroviral therapy compared to their counterparts: a cohort study, 2016–2022

To assess the impact of immigration status and other risk factors on mortality among HIV/AIDS patients receiving antiretroviral therapy (ART). We conducted a cohort study (2016–2022) of 3,795 HIV/AIDS patients aged ≥ 18 years in Yunnan, China. The migrant population was defined as individuals whose household registration and current residence were located in different provinces. Mortality was analysed from patients inclusion to death or censored. Descriptive analysis results were obtained using chi-square tests, Fisher’s Exact test, t-tests, and Poisson regression models were conducted to estimate mortality outcomes( $$\:{\upalpha\:}=0.05$$ ). The total follow-up time for this cohort was 14,263.0 years, with an overall mortality rate of 7.7% (294/3,795). Target population was predominantly male (68.7%) aged 25–49 years (63.3%). After adjusting for demographic and clinical characteristics, there were several variables with significances by Poisson regression, and they were migrant status, age, gender, time to ART initiation, opportunistic infections, viral load, serum creatinine level, and CD4 cell count. It revealed that migrants had a lower risk for mortality (aIRR 0.64, 95% CI: 0.40–0.97), although those 25–49 (aIRR 2.53, 95% CI:1.21–6.49) and ≥ 50 years (aIRR 7.25, 95% CI:3.48–18.55) of age exhibited a higher mortality rate, and women were at lower risk than men (aIRR 0.43, 95% CI:0.31–0.58). Delayed initiation of ART > 30 days increased the risk for mortality (aIRR 1.31,95% CI:1.04–1.67). Mortality was higher among patients with opportunistic infections (aIRR 1.58, 95% CI:1.22–2.05), as well as those with viral load ≥ 50 copies/mL (aIRR 2.77, 95% CI:2.07–3.79) and abnormal serum creatinine levels (aIRR 1.58, 95% CI:1.08–2.26). CD4 cell count ≥ 200 cells/µL were associated with lower mortality ( aIRR 0.62, 95% CI:0.46–0.82). The causes of death were dominated by respiratory diseases, cardiovascular diseases, and other non-AIDS-related diseases. Being migrant was associated with a lower mortality as compared with local natives or other long-settled population. The main factors influencing the risk for mortality among HIV/AIDS patients were migrant status, age, gender, time to ART initiation, opportunistic infections, viral load, serum creatinine level, and CD4 cell count.