“At the time, the life expectancy for people with cystic fibrosis was about 17 years of age, so certainly now, being 31 years old, I’ve come a long way, but still see many good years left in my future hopefully.”
About 4,100 people in Canada have cystic fibrosis, compared with 30,000 in the U.S.
Researchers, including Dr. Anne Stephenson, a respirologist and cystic fibrosis researcher at St. Michael’s Hospital, identified three factors that seemed to account for the difference in survival rates between the two countries:
“When we realized there was a difference in survival rates between the two countries, we realized this is an opportunity to identify reasons for that gap, so we can then implement strategies to close the gap,” she said.
To eliminate the possibility that different techniques in processing data might change the results, researchers used a standard approach to study data from the five years 2009 to 2013. It showed Americans with cystic fibrosis lived to a median age of 40.6 years, compared with 50.9 years for Canadians.
“There are not many therapies that impact survival immediately, and lung transplant is one of those therapies,” Stephenson said.
‘In Canada … although the survival is very good, there are people who die every year at an early age of CF, so we can’t sit back on our laurels, we have to move survival forward.’ – Dr. Anne Stephenson, St. Michael’s Hospital in Toronto
Unlike Canada, the U.S. uses a “lung allocation score” to determine who gets priority for transplants. The scoring system looks at potential improvement and survival after a transplant, said Dr. Bruce Marshall, senior vice-president for clinical affairs at the CF Foundation in the U.S., who was one of the investigators on the study.
“The impact that it’s had is that it seems to be disadvantaging CF patients a little bit,” he said. “The Canadians have stayed with the same allocation system and it’s the front-line clinician that really knows the patients and helps prioritize who should get donor lungs when they become available.”
“The Canadians tried high fat diets, more calories, more palatable, and this really had an impact on the nutritional status, particularly with children, and that seems to set the trajectory for the disease,” he said.
The U.S. began adopting the high fat diet for cystic fibrosis patients in the 1980s, so its survival rates are still catching up.
But the biggest difference may be in the health-care systems of the two countries and equitable access to treatment.
“People who had private insurance in the U.S. had a similar risk of death compared to Canadians … whereas people in Canada had a 77 per cent lower risk of death compared with people in the U.S. with no insurance,” Stephenson said.
Socioeconomic status may also affect care for Canadian cystic fibrosis patients, especially if they do not live close to a clinic where the disease can be treated or cannot afford to take time off work for intensive therapies, Stephenson said.
Researchers say more study is needed to confirm why there is such a difference in survival rates between two countries, and to take into account factors such as air quality, differences in medication usage and in pulmonary function.
The goal is a fuller, longer life for those with cystic fibrosis.
The disease causes the body to produce a thick, sticky mucus that clogs the lungs and leads to life-threatening lung infections. One of the most common causes of death is progressive lung disease, but there also can be complications from the drugs taken for treatment and from other infections.
He’s holding out hope for a cure within his lifetime.
Stephenson agreed there’s still much to be learned about CF.
“In Canada … although the survival is very good, there are people who die every year at an early age of CF, so we can’t sit back on our laurels, we have to move survival forward.”