``We're really falling behind other nations," said Dr. Steffie Woolhandler, an associate professor of medicine at Harvard and a co-author of the new study.
Canada's national health insurance program is at least part of the reason for the differences found in the study, said Woolhandler, an advocate for such a program in the United States. Universal coverage makes it easier for more Canadians to get disease-preventing health services, she said.
James Smith, a RAND Corporation researcher who co-authored the American-English study, said, however, that his research found that England's national health insurance program did not explain the difference in disease rates, because even Americans with insurance were in worse health.
``To me, that's unlikely," he said of the idea that universal coverage explains international differences.
Woolhandler said her findings were different in at least one important respect: In the Canadian study, insured Americans and Canadians overall had about the same rates of disease. It was the uninsured Americans who made the overall US figures worse, she said.
The study, released yesterday, is being published in the American Journal of Public Health. It is based on a telephone survey of about 3,500 Canadians and 5,200 US residents conducted by government agencies in 2002-03. Those surveyed were 18 or older.
The new study found that 6.7 percent of Americans and 4.7 percent of Canadians reported having diabetes; 18.3 percent and 13.9 percent, respectively, reported having high blood pressure; and 17.9 percent and 16.0 percent said they had arthritis. The Americans also reported more heart disease and major depression, but those difference were too small to be statistically significant.
About 21 percent of Americans said they were obese, compared with 15 percent of Canadians. And about 13.5 percent of the Americans admitted to a sedentary lifestyle, versus 6.5 percent of Canadians. However, more Canadians were smokers -- 19 percent, compared with about 17 percent of Americans.