Incidence and treatment outcome of aplastic anemia in Taiwan-real-world data from single-institute experience and a nationwide population-based database.

Aplastic anemia (AA) is a rare disease characterized by pancytopenia and bone marrow failure. The incidence of AA tends to be higher in Asia than in the West, but real-world data about AA in Asia remain limited. We aimed to describe the basic data, treatment, and outcome of AA patients from our institute and evaluate the incidence of AA in Taiwan with a nationwide population-based cohort from National Health Insurance Research Database (NHIRD). We identified patients older than 2 years with AA in the Registry of Catastrophic Illness of NHIRD between 2001 and 2010 and excluded patients with any diagnosis suggestive of congenital or secondary bone marrow failure. With a total of 1270 patients, the overall incidence was 5.67 per million people per year, and there was a biphasic age distribution of incidence rate, highest in ≥ 70 years (19.83 per million people per year) and another peak at age 2-9 years (5.26 per million people per year). Overall, the 5-year survival was 60.0%. Hematopoietic stem cell transplantation (HSCT) and anti-thymocyte globulin-based immunosuppressive therapy (IST) were the major first-line treatments in patients younger than 40 years and were linked with good survival. In contrast, the majority of patients older than 60 years were treated with androgen, and the survival was poor. In multivariate analysis, "severe AA," "very severe AA," and "treatment other than HSCT, IST, or androgen" were independent risk factors for inferior survival. In conclusion, the incidence of AA in Taiwan is consistent with nearby Asian countries and is higher than in the West. Advanced age is associated with higher incidence and poorer outcome.