Warm autoimmune haemolytic anaemia in Taiwan: A population‐based study of epidemiology, treatment patterns, survival and healthcare utilisation (2017–2022)

Summary To describe the epidemiology, treatment patterns, overall survival (OS) and healthcare resource use among patients with warm autoimmune haemolytic anaemia (wAIHA) in Taiwan, adult patients with ≥1 diagnosis code for autoimmune haemolytic anaemia (AIHA) with record of wAIHA‐related treatments between 2017 and 2022 were retrospectively identified from Taiwan's National Health Insurance Research Database linked with the National Death Registry and Taiwan Cancer Registry. The wAIHA incidence was 1.27 per 100 000 person‐years, and the 2022 prevalence was 4.58 per 100 000 persons. Corticosteroid monotherapy was the most common treatment across all lines, with 30.2% of patients remaining on corticosteroids 2 years after diagnosis. Blood transfusions were common in the first year following diagnosis, with 52.5% of patients receiving at least one emergency transfusion. The 5‐year OS probability, estimated using Kaplan–Meier analysis, was 67.1%. The median annualised medical cost was NT$ (New Taiwan dollar) 106 464 (interquartile range [IQR]: 49 088–285 856) or US$ (US dollar) 3327 (IQR: 1534–8933). Intensive care unit admissions were the primary cost driver (adjusted exponentiated coefficient: 2.76 [95% confidence interval: 2.26–3.36]), determined using a generalised linear model with a gamma distribution and log link function. Overall, significant unmet medical needs remain for wAIHA management in Taiwan, including addressing prolonged reliance on corticosteroids, sub‐optimal OS outcomes and high medical service use.