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

Abstract

IntroductionEpidemiological surveillance of haemophilia through linkage of medical records within a US state has not been conducted in 20 years.AimThe 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).MethodsA 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.ResultsIn 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.ConclusionWe observed higher incidence and prevalence of haemophilia in Indiana compared to previous national estimates, as well as higher HTC utilization among persons with haemophilia.

Occurrence rates of haemophilia among males in the United States based on surveillance conducted in specialized haemophilia treatment centres

“…This finding was unexpected since the HSS provided more complete ascertainment in the states studied, and it is known that not all people with haemophilia in the United States receive care in these HTCs. While the exact proportion is unknown, estimates from a more recent study that used the same methodology as the HSS suggest that closer to 80% of the haemophilia population receive care in this HTC network versus the 67% measured in the HSS 1,2 . Based on the 21 748 patients we report in this study and our assumptions about the proportion of US haemophilia males who receive care in HTCs (between 67% and 80%), we estimate that a total of between 29 761 and 32 985 males with haemophilia live in the United States today.…”

“…At the time of the HSS, 67% of the identified population with haemophilia in the six‐state surveillance catchment area received some care in an HTC during a three‐year period 1 . A more recent population‐based study conducted in Indiana found that 81.7% of males with haemophilia identified in that state had visited an HTC during the period 2011‐2013 2 …”

<p>The Need for Comprehensive Care for Persons with Chronic Immune Thrombocytopenic Purpura</p>

“…45 In another CDC-sponsored study, HTCs were shown to reduce mortality among persons with hemophilia by 40% as well as decrease healthcare resource utilization. 45 , 46 Comprehensive care is one of the essential principles in the model for the development of a national healthcare program for patients with hemophilia. 31 HTCs have been established to guarantee patients and families access to all services essential for the management of their bleeding disorder.…”

“…45 More recently, in one US HTC, approximately 81.7% of persons with hemophilia receive care at least once a year. 46 Those that benefit from care at HTCs have a reduced rate of emergency department (ED) utilization and an increased rate of prophylaxis and self-infusion compared to those receiving care outside of the HTC network. 46 …”

Modelling future usage and cost of factor and emicizumab to treat haemophilia A for the US Western States Region IX haemophilia treatment centres

“…Table 7 shows that the average number of PWHA enrolled in the HTCs is estimated at 8 per 100,000 males with 54% being severe 6 whereas a recent US study reports 12.7 per 100,000 males (34% severe). 21…”