Population-based surveillance of haemophilia and patient outcomes in Indiana using multiple data sources

Abstract

Introduction: Epidemiological surveillance of haemophilia through linkage of medical records within a US state has not been conducted in 20 years. Aim: The Indiana Haemophilia Surveillance Project aims to identify all persons with haemophilia who resided in Indiana in 2011-2013 and to determine the percentage of patients in Indiana cared for at a federally recognized haemophilia treatment centre (HTC). Methods: A retrospective review of medical charts was conducted to identify haemophilia cases during the surveillance years. Case-finding methods involved a variety of medical care resources including hospitals, administrative claims data and haematology/oncology clinic reports. Results: In Indiana, 704 unique haemophilia cases were identified. Of those cases, 456 (64.8%) had factor VIII and 248 (35.2%) had factor IX deficiency. Among those with known severity levels (n = 685), 233 (34%) were severe, 185 (27%) were moderate, and 267 (39%) were mild. Overall, 81.7% of the haemophilia patients identified visited an HTC at least once during the three-year study period, which was the requirement for being considered an HTC patient. Age-adjusted prevalence for 2013 was 19.4 haemophilia cases per 100 000 males, 12.7 per 100 000 for factor VIII and 6.7 per 100 000 for factor IX. Incidence of haemophilia over the 10 years prior to the surveillance years was 1:3688 live male births in Indiana. During the surveillance years, 24 cases (3.4%) died. Conclusion: We observed higher incidence and prevalence of haemophilia in Indiana compared to previous national estimates, as well as higher HTC utilization among persons with haemophilia.