To offset escalating health insurance costs, employers andinsurers have been steadily shifting the burden of paying formedical care to the patients themselves. Higher premiums combinedwith increasing out-of-pocket expenses have been the primarystrategies. The result: More people than ever who have healthinsurance are considered to be uninsured.

That’s the conclusion of an analysis of health plan data by theCommonwealth Fund. Its study, “The Problem of Underinsurance and How RisingDeductibles Will Make It Worse,” is an extraction from a largerpiece of research on health insurance in the U.S. The study isbased upon data gathered prior to the launch of Obamacareinsurance, so the data offers no comment on how reform actinsurance may have affected the numbers. Nonetheless, itsimplications for the general health of Americans aredisturbing.

The report compares those who were considered insured butuninsured in 2003 to those who fitthat definition in 2014. The definition is rather subjective;Commonwealth defines it this way:

“People are considered underinsured if they have had healthinsurance for a full year, but have high deductibles or out-of-pocketexpenses relative to their income.”

Essentially, it includes people who say they have insurance butreport that they are not using it. They tend not to use theircoverage for procedures, drugs, and checkups where there areco-pays, often only using it for a major medical event.

By this definition, the number of those in this category doubledbetween 2003 and 2010. That number — 31 million — has not changedsince 2010, Commonwealth said, presumably as more people were ableto afford insurance and afford to use it for medical care. As apercentage of those with insurance, the insured/uninsured rate rosefrom 12 percent in 2003 to 22 percent in 2010.

Fully 20 percent of those individuals or families who had health insurancethrough an employer sponsored plan fell into this category. That’sup from 10 percent in 2003. Of those who purchased insurance ontheir own, 37 percent were insured but realistically uninsured.

“The underinsured rates were higher among those working in smallfirms with health benefits through their jobs—27 percent wereunderinsured compared to 14 percent in firms with 100 or moreworkers,” the report said.