Anemia prevalence and treatment patterns in chronic kidney disease: a nationwide observational study using a Japanese primary care database (2018–2023)

BACKGROUND: Anemia in chronic kidney disease (CKD) is associated with poor outcomes, including CKD progression, mortality, and cardiovascular events. Standard treatments include iron supplements and injectable erythropoiesis-stimulating agents (ESAs). Oral hypoxia-inducible factor-prolyl hydroxylase inhibitors (HIF-PHIs) have recently emerged as a new treatment option, providing easier accessibility for general practitioners. METHODS: This real-world descriptive study used the Japan Medical Data Survey database to analyze the prevalence of anemia, anemia treatment, and treatment type in non-dialysis patients with CKD and treated in primary care clinics. Data from 1 January 2018 to 31 December 2023 were assessed and analyzed by subgroups (year, CKD stage, patient age, treatment setting, sex, and region). RESULTS: This study included 397,419 patients. Anemia treatment rates increased from 16.4% (2018) to 22.7% (2023), accompanied by an increased proportion of patients with hemoglobin levels ≥ 11 g/dL (78.8%-87.9%). From 2020, use of HIF-PHIs increased and use of ESAs decreased, with HIF-PHIs overtaking ESAs in 2022-2023. During 2022-2023 (N = 340,398), patients with more severe CKD stages had lower hemoglobin levels and an increased prevalence of anemia (11.6% [CKD G3a]-73.6% [CKD G5]). Older patients tended to have lower hemoglobin values, increased anemia prevalence, more severe CKD, and increased use of HIF-PHIs and ESAs. CONCLUSION: Use of HIF-PHIs in primary care settings in Japan is increasing, resulting in changes to anemia treatment received by patients with CKD.