Canadians with cystic fibrosis survive, on average, more than 10 years longer than Americans with the same disease, largely because of differences in the two countries’ health insurance systems, a new study suggests.

Cystic fibrosis is an inherited disease that causes recurrent lung infections and other problems. The average lifespan for an American with the illness is 37 years. In Canada, it is 49.

Researchers studied records of 5,941 Canadian and 45,448 American cystic fibrosis patients between 1990 and 2013. After controlling for severity of disease, age and other factors, they found that overall death rates were 34 percent lower in Canada than in the United States.

There was no difference in death rates between Canadians and Americans with private health insurance. But Canada provides universal health care coverage under a single-payer system, so every Canadian has some kind of health insurance. The Canadian death rate was 44 percent lower than that of Americans on Medicaid or Medicare, and 77 percent lower than Americans without insurance.

The study, in Annals of Internal Medicine, found that 10.3 percent of Canadian patients received lung transplants, which can prolong survival, compared with 6.5 percent of Americans. The lead author, Dr. Anne L. Stephenson, a researcher at St. Michael’s Hospital in Toronto, said that that probably plays a role in the disparity.

But, she added, “It seems people with no insurance have the worst outcomes compared to Canadians. That was the largest difference seen.”