Hemophilia disease 3 times more prevalent than previously thought, study finds

The number of men living with hemophilia — an inherited bleeding disorder — is three times what was previously known, researchers at McMaster University say.

In a new study published Monday in the Annals of Internal Medicine, the researchers say more than 1,125,000 men around the world have hemophilia, and 418,000 of those have a severe version of the mostly undiagnosed disease.

Knowing how many patients are out there will enable health care systems to estimate the resources needed to treat the disease.- Dr. Alfonso Iorio

"This paper is a milestone in our journey to providing care for hemophilia patients worldwide," said Dr. Alfonso Iorio, lead author of the paper.

"Knowing how many patients are expected in each country, given its population, is an important measure of the efficiency of the health-care system. Knowing how many patients should be there, and how many less instead are reported to national and international registries is a measure of the work left to be done."  

Only 400,000 people globally were estimated to have the disorder, which is caused by a defect in the F8 or F9 gene, which encodes instructions for making the factor proteins that helps blood clot.

For those with hemophilia, lack of treatment leads to chronic and disabling joint disease, while bleeding into organs and brain hemorrhages can lead to disability and death.

Hemophilia, which is found almost only in men, is currently treated with infusions of factor to prevent or stop debilitating bleeds, but treatment is expensive and scarce in many countries.

The international research team arrived at its findings by analyzing data from countries around the world. The study was conducted over a two-year period starting in late 2017, and the researchers considered data from 1991 to 2015, with particular emphasis of data from the last 15 years.

The team was also able to calculate, for the first time, the prevalence of hemophilia among babies at birth, which enabled them to estimate life expectancy of those with hemophilia, particularly in lower-income countries where there is lack of treatment.

"Knowing how many patients are out there will enable health care systems to estimate the resources needed to treat the disease, and enable drug manufacturers to increase the investment in research to match the demand of a patient population three times larger than we previously thought," Iorio said.

Iorio is professor health research methods, evidence, and impact at McMaster University, and director of the Hamilton-Niagara hemophilia program at Hamilton Health Sciences.

2 main types of hemophilia

There are two main types of hemophilia. Hemophilia A has the factor 8 (F8) gene defect, and hemophilia B has a factor 9 (F9) gene defect.

The researchers found that, per 100,000 males, 21 will have hemophilia A or B, seven of them severely.

Among newborns, per 100,000 males, 29 will have hemophilia A or B, of whom 12 will have the severe form of disease.

Putting the numbers together, the 'life expectancy disadvantage' associated with hemophilia may be estimated and varies depending with the availability of care. For those born with hemophilia, the chances of living a life of normal duration and quality will be reduced by 64 per cent in upper-middle income countries, 77 per cent in middle income, and up to 93 per cent in low income countries.

For the World Federation of Hemophilia, Iorio assembled an international team of researchers from France, U.S. and U.K. to perform a meta-analysis of the registry data in countries with the most comprehensive registries of hemophilia, which were Australia, Canada, France, Italy, New Zealand and the U.K.

Almost 4,000 hemophilia patients in Canada

At the end of 2018, there were 3,006 hemophilia A patients and 665 hemophilia B patients in Canada. Of this number 370 are living in Hamilton — 154 of which have a severe form of the disease.

Noting that hemophilia is "a very expensive disease," Iorio says it costs between $300 and $400 million per year to treat all these patients.

"In Canada we capture them all but if you think of other, less developed countries, you get 10 per cent of them and all the others are just left untreated," Iorio told CBC Hamilton.

"Treatment is available. But if you don't treat them, they end in having severe joint problems, they end on wheelchairs, or they can bleed to death."

The Canadian hemophilia registry based at McMaster University is funded by the provinces and territories at a cost $500,000 per year.

"It has an enormous return because in countries like ours where we know exactly how many patients we have, we keep them controlled." He said in Canada it costs about one-third of what it costs in the U.S. to treat these patients.

"So yes, there is a cost to keep the registry up and to be able to collect the data and provide optimal care. But the return in terms of savings is humongous."

Hemophilia Ontario welcomes new data

Hemophilia Ontario, one of several such organizations in Canada, welcomes the new data. Executive director Byron James said he is not in the least surprised that there are far more cases of hemophilia than originally thought.

James, who started in the position nine months ago, says he has found it to be a real challenge even to get a proper breakdown of the number of people within his organization with hemophilia A or B. 

"You need to know who your population is in order to budget and in order to allocate resources, what types of education programs are needed. This is a disease that needs to be managed," James told CBC News.

"In order to manage it you need to know you have it, and we need to know the breakdown of the populations that are out there. How many of them are children that are going to be transitioning into adults and what's the process when they have to manage the disease totally on their own as opposed to maybe mom and dad helping them?

"I think the more data the better, for everybody," James added.