Incidence and correlates of chronic anemia in people living with HIV Initiating ART: An exploratory five-year retrospective cohort of patients retained in care

Chronic anemia remains a common and clinically important complication among people living with HIV (PLWH) receiving antiretroviral therapy (ART), contributing to increased morbidity and mortality, particularly in persistent or severe cases. This study estimated the incidence and correlates of chronic anemia among PLWH initiating ART in Zambia. A five-year retrospective cohort study was conducted among 243 adults who initiated ART between February 2015 and December 2020. Chronic anemia was defined as hemoglobin levels <13 g/dL for men and <12 g/dL for women persisting for more than six months. Hemoglobin levels were assessed at ART initiation and at least every six months thereafter. Participants were stratified by anemia status at baseline and followed for up to 60 months. Kaplan-Meier analysis was used to estimate anemia-free survival, and Cox proportional hazards models were used to identify exploratory correlates. Over five years, 125 participants (51.4%; 95% CI: 45.0%-57.9%) developed chronic anemia, with an overall incidence rate of 10.3 per 100 person-years. Among participants without anemia at baseline, the incidence rate was 2.91 per 100 person-years, while those with baseline anemia had a higher incidence of 15.31 per 100 person-years. Those with anemia at baseline, female sex (AHR 2.28; 95% CI: 1.12-4.62), severe anemia (AHR 8.06; 95% CI: 2.84-22.92), moderate anemia (AHR 5.72; 95% CI: 2.51-13.03), mild anemia (AHR 5.29; 95% CI: 2.15-12.99), and microcytosis (AHR 5.19; 95% CI: 1.19-22.74) were significantly associated with chronic anemia. Among participants without baseline anemia, zidovudine-containing regimens were independently associated with chronic anemia (AHR 4.43; 95% CI: 1.02-19.34). Chronic anemia remains a substantial clinical problem among PLWH receiving ART, particularly among those with baseline anemia and specific hematologic risk factors. These findings highlight the importance of early identification and monitoring of individuals at risk of persistent anemia during ART.