Fewer HIV infections and better care may explain the higher prevalence of hemophilia in male patients in Indiana between 2011 and 2013 than previously reported in six other states, according to a new study.
The findings also revealed a higher utilization of Hemophilia Treatment Centers (HTCs) by this patient population.
The research was published in a study, “Population‐based surveillance of haemophilia and patient outcomes in Indiana using multiple data sources,” in the journal Haemophilia.
The most comprehensive study of hemophilia patients in the U.S. was done more than 20 years ago, when the Centers for Disease Control and Prevention (CDC) collaborated with the health departments in Colorado, Georgia, Louisiana, Massachusetts, New York, and Oklahoma. Among other findings, this study, published in 2000, showed that HTCs helped reduce mortality in this patient population by 40% and reduced the use of healthcare resources and the cost of care.
Modeled after that study, the Indiana Haemophilia Surveillance System intended to identify all hemophilia patients living in Indiana between 2011–2013, including those not served by an HTC. This subsequent study resulted from a collaboration between the CDC, the Indiana State Department of Health, and the Indiana Hemophilia and Thrombosis Center.
Medical records were obtained from hospitals in contact with potential hemophilia cases, as well as from hematologists/oncologists, primary care physicians, and administrative claims records, among other sources.
The study identified 704 males with hemophilia (median age was 25 years). The study population was younger than the overall population in Indiana (35.9 years) and the U.S. (36.1 years), with higher proportions of patients 5-34 and lower proportions of patients who were older than 35. Adult patients numbered 453, representing 64.3% of the cases.
A total of 456 (64.8%) patients had factor VIII deficiency, which means hemophilia A, and 248 (35.2%) had factor IX deficiency — hemophilia B. Among the 685 patients with known disease severity, 233 (34%) were severe, 185 (27%) were moderate, and 267 (39%) were mild.
Although accounting for 7% of the study population, Amish patients represented 17.7% of all hemophilia B cases. Most patients (85.5%) were non‐Hispanic white, 8.5% were non‐Hispanic Black, and 1.7% were Hispanic.
Overall, 575 patients (81.7%) visited an HTC at least once during the study period. Among the 129 who did not, most (27.9%, or 36) received care primarily from an emergency department, while 23.3% (30) were seen by a private hematologist. The vast majority of the severe cases (95.1%) were seen at an HTC.
The data further showed that 75% of the patients with severe hemophilia were on prophylaxis (preventive) therapy at some point during the study period. The proportion of such patients seen at an HTC was 30% higher than those seen outside the HTC network.
Sixteen (2.3%) patients developed inhibitor antibodies against their clotting factors, most (81%) of whom were seen within the HTC network. Thirty‐eight (5.4%) experienced an intracranial hemorrhage, 28 (4.1%) had a HIV infection, and 134 (19%) had hepatitis C.
Most people with hemophilia (89.2%) had insurance. Private insurance was the most common (39.3%), followed by Medicaid (27.2%), Medicare (13.1%), and state-sponsored insurance (2.2%). In addition, 57% of the patients without insurance were Amish, and 94.7% of all hemophilia patients without insurance were cared for at an HTC.
Of all patients receiving care at an HTC, 17.6% required emergency department services compared with 33.3% of non‐HTC patients.
The estimated 2013 hemophilia prevalence in Indiana was 19.4 cases per 100,000 males, 45% higher than previously reported in the U.S.
Among other explanations for this difference, the researchers mentioned “the dramatic reduction in HIV infections in younger cohorts and the impact of HIV treatments in decreasing mortality.” Improved care was a further reason, “including the widespread adoption of prophylaxis, which contributed to increased longevity,” they added.
Patients older than 35 had severe hemophilia less commonly than mild and moderate disease. Also, the prevalence of hemophilia in men aged 65 and older was 9.8 per 100,000 compared with approximately five per 100,000 males in previous data, thereby reflecting that patients are living longer.
As for disease types, the prevalence of hemophilia A was 12.7 per 100,000 while hemophilia B’s prevalence was 6.7 per 100,000. Disease incidence in Indiana over the 10 years prior to 2011 was 30.1 per 100,000 or 1:3,688 live male births.
Twenty‐four patients (3.4%) died during the three-year period, all but one of them were adults. The median age of death was 57.5 years, younger than that of males in the U.S. (79 years). Most patients who died (20) had mild or moderate hemophilia. Hemophilia‐related causes such as non‐traumatic intracranial hemorrhage were among the primary causes of death, as were non‐hemophilia‐related causes such as cirrhosis, cancer, heart disease, and respiratory failure.
Overall, “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,” the scientists wrote.
“This type of surveillance, while time consuming, may be one of the better ways to collect population‐level data on patients with haemophilia so as to track the impact of new therapies for haemophilia and give a more complete estimate of disease frequency,” they concluded.