Burden of congenital hemophilia A requiring treatment in Japan: The HIKOBOSHI study

BACKGROUND: Treatment of congenital hemophilia A (HA) in Japan has greatly improved with the widespread adoption of prophylactic factor (F)VIII concentrates. However, it is unknown if this has translated into a real‐world reduction in disease and treatment burden. OBJECTIVES: To describe HA disease burden in Japan based on information from two medical information databases, JMDC and Real World Data Co., Ltd. (RWD). METHODS: Eligible individuals were diagnosed with congenital HA and prescribed FVIII concentrates, bypassing agents, or emicizumab. Treatment patterns and disease burden data were derived from health insurance claims and electronic medical records. RESULTS: Data on 459 people with HA were retrospectively collected from 2005 to 2020 in the JMDC database (median [min, max] of 37 [2, 186] months of available records), and 229 people with HA from 1985 to 2020 in the RWD database (median [min, max] of 154 [0, 409] months of available records). Mean (standard deviation) ages at the time of the first record were 25.0 (16.8) years (JMDC) and 19.2 (20.3) years (RWD). In the JMDC database, mean monthly FVIII dose increased from 2201 IU in 2005 to 8239 IU in 2013 to 11,377 IU in 2019; HA‐related drug costs increased accordingly. Mean (95% confidence interval) annual outpatient and out‐of‐hours visits decreased slightly between 2013 and 2019 (outpatient visits: from 22.9 [16.8–29.0] to 14.3 [12.6–16.1] per person; out‐of‐hours visits: from 1.3 [0.2–2.5] to 0.6 [0–1.4]). There was no change in mean number of hospitalizations. CONCLUSIONS: Challenges remain in HA, including treatment burden, outpatient visits, and hospitalizations.