The burden of anemia among Chinese HIV-infected patients following the initiation of antiretroviral therapy in the treat-all era: a nationwide cohort study

Background To assess the prevalence of anemia before and after antiretroviral therapy (ART) initiation and to identify impact of anemia on mortality among HIV-infected patients in China during the Treat-All era.Methods All HIV-infected patients who newly initiated ART between January 1, 2017 and December 31, 2020 were enrolled and followed up to December 31, 2021 in China. We analyzed the prevalence of anemia before and after ART initiation. Generalized estimating equations were fitted to determine factors associated with anemia after ART. Time-dependent cox proportional hazards models were performed to estimate the effect of anemia on death.Results Of 436,658 patients at the baseline of ART initiation, the overall prevalence of anemia was 28.6%. During a median 2.65 (IQR: 1.80-3.51) years of follow-up after ART initiation, 376,325 (86.2%) patients had at least one Hb measurement (a total of 955,300 hemoglobin measurements). The annual prevalence of anemia after ART was 17.0%, 14.1%, 13.4%, 12.6% and 12.7%, respectively. Being anemic at the baseline of ART initiation (adjusted odds ratio, aOR = 6.80, 95% confidence interval (CI): 6.67-6.92) was the strongest factor associated with anemia after ART. Anemia status after ART showed a strong association with death after multivariable adjustment (mild anemia: adjusted hazard ratio (aHR) = 2.65, 95% CI: 2.55-2.76; moderate anemia: aHR = 4.60; 95% CI:4.40-4.81; severe anemia: aHR = 6.41; 95% CI:5.94-6.91).Conclusions In the era of ART universal access, pre-ART anemia was common among HIV-infected patients. Notably, a certain proportion of anemia still persisted after ART, and was significantly associated with death. We recommend strengthening the monitoring of patients at risk of anemia, especially in patients with baseline anemia or during the first year of ART, and timely treatment for correcting anemia.