Lack of health coverage is keeping about 11 million chronically ill U.S. residents from getting needed medical care.

Researchers with the Cambridge Health Alliance, Cambridge, Mass., and at other organizations have published that finding, based on analysis of data from the National Center for Health Statistics, in the Annals of Internal Medicine, a medical journal.

Dr. Andrew Wilper, the lead author, who teaches at the University of Washington School of Medicine in Seattle, and the other researchers found that about 23% of working-age adults with 1 or more chronic illnesses had not seen a health professional within the previous year, and that about 7.1% of those uninsured adults got their standard health care in a hospital emergency room.

Only 6% of insured working-age adults with chronic illnesses had gone without seeing a doctor for more than a year, and only 1.1% of those insured adults got their standard care in emergency rooms.

The researchers have identified 11 million uninsured nonelderly adults in the U.S. with at least 1 chronic condition.

About 1.3 million have survived a heart attack or stroke, 5.9 million have high blood pressure, 1.4 million have diabetes, and 3.5 million have asthma or emphysema.

In total, they represent about one-third of the total number of uninsured U.S. residents between the ages of 18 and 64, the researchers estimate.