Washington - Americans who spend years without medical insurance become healthier once they qualify for public health insurance provided for retirees, a study to be published Wednesday says. The report in the Journal of the American Medical Association (JAMA) appears at a time when 47 million people in the US - 15 per cent of the population - lack health insurance, a major issue on the presidential campaign that will be decided in November 2008.
The study tracked 7,233 people age 55 to 72 for 12 years, ending in 2004. The number included 2,227 people who were uninsured or only intermittently insured until they qualified for Medicare at age 65, according to a press release on Tuesday.
For every 100 uninsured people with heart disease or diabetes before age 65, the study found they had 10 fewer major cardiac problems such as heart attacks or heart failure, than expected by age 72, the study found.
"The study provides strong evidence about how health improves when people gain insurance coverage," said Dr. John Ayanian, senior author of the study and a professor at Harvard Medical School.
Dr J Michael McWilliams, a Harvard research associate, conceded the outcome seemed "self-evident" - but some people question "this assumption."
Earlier this year, the same authors published a study in the New England Journal of Medicine showing that uninsured adults who gain coverage from Medicare end up costing the system more compared to continuously insured people.
"Together, the two studies suggest that expanding health coverage is less costly than previously believed and slows declines in health as well," said Ayanian.