An article appearing last month in the journal Haemophilia focused on disparities between countries in the reported prevalence of hemophilia A (per 100,000 males).
Prevalence was determined by each country using a straightforward formula: the total number of reported or identified cases of hemophilia A in the population at a given time divided by the total number of males in that population. The prevalence data referred to in the article came from the 106 countries that submitted annual global survey reports to the World Federation of Hemophilia (WFH) and from additional literature.
The authors discovered that the prevalence of hemophilia A “varied considerably,” even among the wealthiest nations. They also found that the reported hemophilia A prevalence in poorer countries is typically much lower than in higher income countries.
Data gleaned from WFH’s global survey also showed that prevalence does not remain static but instead can shift. In the early 1970s, the reported hemophilia A prevalence in the United Kingdom (UK) was approximately 10 per 100,000 males, while the U.S. reported a rate of approximately 20 per 100,000 males. Three decades later, the reported data show a near reversal: for 2006 the U.S. reported prevalence of 8 per 100,000 males, while the UK reported 20.7 per 100,000. In fact, within countries, survey data showed a clear trend of rising prevalence over time, with Canada increasing from 10.2 in 1989 to 14.2 in 2008 and the UK increasing from 9.3 in 1974 to 21.6 in 2006.
The authors also highlighted the problem of “under-reporting,” such as in Africa and Asia. Citing prior research, they pointed to such likely causes as: (1) lack of diagnostic capability to identify patients; (2) little or no access to care; (3) no economic means; and (4) little to no available factor VIII (FVIII) replacement therapies.
“In addition, the reporting procedures in many countries have not accurately identified people with haemophilia A. Countries with marginal economies typically do not provide resources (both personnel and treatment products) for treating rare, chronic, and expensive conditions (e.g. haemophilia) since they focus their limited resources on public health issues that affect larger portions of the population, e.g. lack of sanitation, malnutrition, combating infectious diseases,” explained the authors.
While the literature suggests that hemophilia A and B incidence is the same for all populations and racial groups – estimated to be 20 per 100,000 male births – several examples (from other studies) of below average prevalence numbers in Africa and Asia seem to support the authors’ explanations. Individuals with hemophilia registered by the Haemophilia Federation of India account for only about 10% of what is expected, while hemophilia patient registry data in Malaysia and South Africa account for less than 50% of expected cases. Only five of 11 countries in Africa reported data on the number of people with hemophilia A; of those, the prevalence ranged from 1.7 to 6.5 per 100,000 males. Only four of nine countries in South America reported data; of those, the prevalence ranged from 3.0 to 9.3 per 100,000 males. Just three of 10 countries in Asia reported data; of those, prevalence ranged from 2.9 to 3.6 per 100,000 males.
While establishing the existing and formidable obstacles to accurate reporting, the authors ended on an optimistic note, citing the likelihood of improved reporting in the future and the accompanying benefits.
The article, “A Study of Variations in the Reported Haemophilia A Prevalence Around the World,” was published online October 21, 2009 by Haemophilia.