How Has Living With Severe Hemophilia Changed in the Last 50 Years? An Analysis of a Large National Database

In an analysis of data from nearly 5,000 men with severe hemophilia collected over the last half century, researchers have illustrated the experience of living with this disease – and how the advances and setbacks in the treatment of hemophilia have affected patients’ clinical outcomes.

Marshall A. Mazepa, MD, from the Department of Pathology and Laboratory Medicine at the University of North Carolina at Chapel Hill, and colleagues, used data from a national health surveillance program launched by the Centers for Disease Control and Prevention and the U.S. Hemophilia Treatment Center Network (HTCN), a federally funded national network of hemophilia diagnostic and treatment centers.

“Over approximately the last five decades, the experience of men and boys with hemophilia has been characterized by remarkable progress in drug therapies and the delivery of multidisciplinary care, interrupted by tragic setbacks from transfusion-transmitted infections,” Dr. Mazepa and co-authors wrote. “Incremental improvements in the standards and access to care as well as setbacks related to treatment complications have naturally created ‘eras’ of care affecting successive birth cohorts of men with severe hemophilia.”

The researchers examined demographics, complications of hemophilia and its treatment, and mortality among patients in each of these eras, to provide a descriptive analysis of how outcomes have changed over time.

A total of 7,486 men were included in the study: 4,899 men (65.4%) had severe factor VIII and IX deficiency and 2,587 men (34.6%) had mild hemophilia. Hemophilia severity was classified based on the plasma level of baseline factor activity: Patients with severe hemophilia had levels <1 percent of normal and patients with mild hemophilia had levels of >5-50 percent of normal.

Patients were categorized into four birth cohorts:

  • Era A: born before 1958
  • Era B: born between 1958-1975
  • Era C: born between 1976-1982
  • Era D: born between 1983-1992

A majority of these patients had hemophilia A (6,094 or 81.4%); 1,392 patients (18.6%) had hemophilia B.

Severely affected men in each birth cohort were compared with the corresponding “mild” hemophilia birth cohorts (2,587 men total) to control for outcomes that might be attributable to aging and environmental factors independent of severely defective hemostasis.

While the first three eras (A-C) contained “roughly similar” numbers of men with severe hemophilia, Dr. Mazepa and colleagues wrote, the number of men with severe hemophilia compared with mild hemophilia increased within each birth cohort in the later eras, to the tune of 2.0 to 2.9 times more severe hemophilia cases in eras B-D. Only in era A did men surviving with mild hemophilia outnumber men with severe hemophilia.

Compared with men in era A, those in era D reported starting treatment in the home earlier in their lives: 45 percent started before the age of six, versus just 2 percent in era A. Similarly, the number of patients visiting a hemophilia treatment center before the age of two increased nearly 10-fold (7.3% in era A vs. 69.1% in era D).

Patients with severe hemophilia were twice as likely to have Medicaid and/or Medicare, compared with patients with mild hemophilia. “Despite this, individuals in the two youngest cohorts [eras C and D] were also more likely to be uninsured, a pattern that was true regardless of severity of hemophilia,” noted Dr. Mazepa and colleagues.

The authors observed several encouraging trends through the eras, due to the advances in treatment, including the proportion of participants reporting frequent bleeds decreasing with each successive era. However, frequent bleeds were still common even in era D, when contemporary therapies were available; more than one in three participants with severe hemophilia in this era reported experiencing more than five bleeds in six months, and 25 percent reported a target joint with recurrent hemorrhage.

Physical functioning capacity was lowest in era A, though those with severe hemophilia across all eras were approximately three times more likely to report activity limitations and twice as likely to report intermittent use of assistive devices for mobility and ambulation than those in the comparative mild hemophilia cohorts.

“As expected, we observed infrequent bleeding in men with mild hemophilia consistently across all eras,” the authors reported, and, though “men with mild hemophilia reported low levels of disability or limitations of activity in the youngest era, these limitations were incrementally more prevalent in each subsequently older birth cohort.” These observations suggest that the recorded limitations in overall activity represent the effect of aging in combination with the infrequent bleeding events.

Despite the advances in treatments over the decades, infections continued to remain a concern among this patient population, as 95 percent of men with severe disease in eras A and B, 90 percent in era C, and 35 percent in era D had been diagnosed with HBV (hepatitis B), HCV (hepatitis C), HIV (human immunodeficiency virus), or a combination of these. However, there were no new infections of HBV, HCV, or HIV attributable to plasma-derived or recombinant coagulation factor therapy since 1992. The highest prevalence of HIV infection occurred among men born during era B, and the prevalence declined in each successive era – to 1 percent in era D.

(See TABLE 1 and TABLE 2 for more details on disease- and treatment-related complications for each birth cohort.)

A total of 551 deaths were reported during the study period, with era A and era B accounting for 82 percent of deaths in the severe hemophilia population and 96 percent of deaths in the mild cohort. Liver failure was the most commonly reported cause of death overall for both severe (33%) and mild (26%) disease.

“If hemophilia treatment and access to treatment for men with severe hemophilia had improved markedly over the last several decades, then we would expect health outcomes disparities to narrow over time,” said Dr. Mazepa and co-authors. “Despite improved access to comprehensive care and to pathogen-free clotting factor for those born in recent decades, the gap between severe and mild has not narrowed either for target joints or for the use of assistive devices for mobility. These “disappointing” observations indicate that there is a need for continued improvement in strategies for prevention and treatment of hemophilia-associated hemorrhage.

One limitation of this large registry data analysis is that patients had to survive until 1998 to be included in the analysis; evaluating only survivors could underestimate the adverse outcomes in severe disease and in the older eras. Interpretation of some data is limited by the lack of historical data and treatment data, for example, whether a patient had past inhibitors or the details of secondary or primary prophylaxis.


Reference
Mazepa MA, Monahan PE, Baker JR, et al. Men with severe hemophilia in the United States: Birth cohort analysis of a large national database. Blood. 2016 March 16. [Epub ahead of print]

TABLE 1. Disease-Related Complications
  Era A Era B Era C Era D
  <1958 1958-1975 1976-1982 1983-1992
  Severe Mild Severe Mild Severe Mild Severe Mild
Total number of patients 688 843 1,542 787 1,121 427 1,548 530
Employment and Disability Status
Disabled 45.9% 12.9% 37.8% 14.7% 15.9% 3.5% 5.8% 1.9%
Employed/
Student
31.2% 49.5% 53.1% 74.5% 68.6% 86.4% 79.6% 87.6%
Retired 18.3% 31.7% 0.4% 0.5% 0% 0% 0% 0%
Other 3.5% 5.9% 8.6% 10.3% 15.5% 10.1% 14.5% 10.6%
Physical Function
Limitation to overall activity level 68.8% 21.1% 49.4% 16.3% 25.9% 6.6% 14.9% 4.3%
School/work absenteeism (>10 days missed) 6.9% 2.6% 8.5% 5.2% 10% 5.6% 5.6% 3%
Assistive devices: intermittent 39.8% 16% 35.1% 15.4% 28.8% 13.6% 22.9% 11.3%
Assistive devices: always 18.5% 4.6% 6.6% 1.5% 1.7% 0% 1.4% 0.8%
Bleeding Complications
≤2 joint bleeds in last six months 45.8% 97.2% 38.1% 92.9% 41.3% 92% 51.7% 94.7%
≥5 joint bleeds in last six months 42.6% 1.7% 48.8% 4.3% 46.6% 3.8% 35.5% 3%
Target joint 32.6% 3.2% 36.2% 7.2% 35.6% 5.8% 24.9% 2.3%

TABLE 2. Treatment-Related Complications
Era A Era B Era C Era D
<1958 1958-1975 1976-1982 1983-1992
Severe Mild Severe Mild Severe Mild Severe Mild
Total number of patients 688 843 1,542 787 1,121 427 1,548 530
Viral Infections
HBV 70.5% 33% 71.7% 34.4% 38.4% 9.1% 5.2% 2.4%
HCV 92.3% 54.2% 93% 60.6% 84.4% 33.3% 32.6% 6.2%
HBV and HCV co-infection 69.2% 27.9% 61.2% 31.5% 34.2% 6.1% 3.7% 0.4%
HIV 42.9% 4.7% 61% 11.9% 26.2% 4% 1% 0.2%
HIV and HCV co-infection 42.2% 4.2% 59% 10.8% 23.3% 3.7% 0.7% 0%
Not infected with HIV, HBV, or HCV 5.5% 40.7% 4.1% 35.8% 10.4% 63.7% 65.4% 91.5%
Inhibitor Development
Any inhibitor recorded 17% 3.3% 13.6% 3.6% 11.5% 2.8% 15.6% 2.8%
HBV = hepatitis B virus; HCV = hepatitis C virus; HIV = human immunodeficiency virus

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