The changing prevalence of anemia and risk factors in people with HIV in North America who have initiated ART, 2007-2017

Objective: To characterize the prevalence of anemia and risk factors between 2007 and 2017 for moderate/severe anemia among people with HIV (PWH) in North America who have initiated antiretroviral therapy (ART).

Design: Observational study of participants in the North American AIDS Cohort Collaboration on Research and Design (NA-ACCORD).

Methods: We estimated the annual prevalence between 1 January 2007 and 31 December 2017 of mild (11.0-12.9 g/dl men, 11.0-11.9 g/dl women), moderate (8.0-10.9 g/dl regardless of sex) and severe (<8.0 g/dl regardless of sex) anemia. Poisson regression models with robust variance and general estimating equations estimated crude and adjusted prevalence ratios (aPR) with 95% confidence intervals ([-]) comparing risk factors for moderate/severe vs. no/mild anemia between 2007 and 2017.

Results: Among 73 898 PWH we observed 366 755 hemoglobin measurements following ART initiation, 37 301 (50%) had one or more measures of anemia during follow-up (mild = 17 743 [24%]; moderate = 13 383[18%]; severe = 6175 [8%]). Moderate/severe anemia was more prevalent among women, non-Hispanic Black and Hispanic PWH (vs. non-Hispanic white), those with underweight body mass index (<18.5 kg/m2) and with comorbidities and coinfections. Older age had increased prevalence of moderate/severe anemia among males and decreased prevalence among females. Prevalence of moderate/severe anemia was greater among those with lower CD4+ cell count (≤200 cells/μl) [aPR = 2.11 (2.06-2.17)] unsuppressed HIV viral load (>200 copies/ml) [aPR = 1.26 (1.23-1.29)] and within the first 6 months of ART initiation (vs. >1 year of ART) [aPR = 1.66 (1.61-1.72)].

Conclusion: The prevalence of anemia among PWH is reduced after ART initiation but remains high. Risk factors differ by sex and include comorbidities and HIV disease severity. The persistent, substantial prevalence of anemia among PWH merits further investigation, targeted screening, and clinical interventions.