Canadians with cystic fibrosis, an inherited disease which attacks the lungs, tend to live a decade longer than Americans suffering from it, likely due to diet, medical insurance and the availability of transplants, researchers said Monday.
The median -- or midpoint -- age of survival for people with cystic fibrosis in Canada is 50.9 years compared to 40.6 years in the United States, said the report in the Annals of Internal Medicine.
Furthermore, people in Canada with CF faced a 34 percent lower risk of dying than their US counterparts, when researchers took account of factors such as age and the severity of the disease.
The study, funded by the US Cystic Fibrosis Foundation, compared records on more than 45,000 US patients to nearly 6,000 Canadian patients.
The lifespan findings focus on the last five years of data available, from 2009 to 2013.
"Survival has increased in both countries, but Canada began to see greater improvements than the United States starting in 1995, with an even more dramatic increase in the survival rate in Canada noted in 2005," said Anne Stephenson, cystic fibrosis researcher at St. Michael's Hospital in Toronto.
The study did not delve into the reasons for the difference, but experts say clues are available.
Beginning in the 1970s, Canadians with cystic fibrosis were exposed to a high fat diet, which has been shown to improve their survival and could have led to better lifespan rates by the mid-1990s.
The United States did not pick up on this trend until the 1980s.
Lung transplants -- one of the few treatments for cystic fibrosis that can boost survival -- are more common in Canada than in the United States.
When it came to health insurance, no difference was seen in survival when comparing US patients with private health care insurance compared to Canadians who have universal, publicly funded healthcare coverage.
"However, Canadians had a 44 percent lower risk for death than US patients receiving continuous Medicaid or Medicare," said the study, referring to US government funded healthcare programs for the poor and elderly.
Canadians had a 77 percent lower risk of dying compared to people with unknown or no health insurance.
Cystic fibrosis is a chronic disease caused by a faulty gene. It affects the lungs and digestive system, leading to thick mucus buildup in the lungs.