The finding comes from a huge survey of 5,006 Americans with health insurance and 2,227 Americans who were persistently or intermittently uninsured from ages 55 to 64.
J. Michael McWilliams, MD, of Brigham and Women's Hospital and Harvard University and colleagues rated participants' health in terms of general health, change in general health, mobility, agility, pain, and depressive symptoms. They also collected specific data on people with heart disease and on measures of blood-sugar control for people with diabetes.
The bottom line: If you don't have health insurance, your health gets worse and worse compared with people with health insurance. That changes at age 65, when universal Medicare health care coverage kicks in. Then you stop losing ground -- although you're not likely to become as healthy as someone who had health insurance all along.
"Providing earlier health insurance coverage for uninsured adults, particularly those with cardiovascular disease or diabetes, may have considerable social and economic value for the United States by improving health outcomes," McWilliams and colleagues conclude.
Their report appears in the Dec. 27 issue of The Journal of the American Medical Association.