As the gap in wealth among Americans continues to widen, so does the divide in health insurance and access to health services.

A new study released Feb. 7 finds that adults in low- and moderate-income families are more likely to be uninsured, to lack a regular source of healthcare, and to struggle to get necessary health services compared to individuals in higher-income families.

"We expect to see a widening gap in healthcare over the next several years,” Sarah Collins, vice president for Affordable Health Insurance at the Commonwealth Fund, said during a Feb. 6 media briefing.

Nearly three of five – or 57 percent – of those in families earning less than 133 percent of the federal poverty level were uninsured for a time in 2011 while two out of five were uninsured for one or more years, according to the first Commonwealth Fund Health Insurance Tracking Survey of U.S. Adults. More than one-third – or 36 percent – of adults in moderate-income families – those earning between $29,726 and $55,875 for a family of four – were uninsured during the year, and 18 percent had been uninsured for two years or more.

Low- and moderate-income adults who were uninsured during the year were much less likely to have a regular source of healthcare than people in the same income range who were insured all year. In addition, uninsured lower-income adults were more likely than insured adults in the same income group to cite factors other than medical emergencies as reasons for going to the emergency room. These included needing a prescription drug, not having a regular doctor, or saying that other places cost too much.

In contrast, just 12 percent of adults in families with incomes at or above $89,400 for a family of four were uninsured during the year, and only 3 percent were uninsured for two years or more.

"The urgency for looking at this group is underscored by the widening income divide in the U.S. as a whole,” Collins said. "Because lower income adults are more likely to lack health insurance coverage they are also disproportionately likely to lack access to care.”

Lack of health insurance coverage, as well as income, had a significant impact on how often individuals accessed care, such as recommended preventive services. Just 10 percent of low-income uninsured adults age 50 and over had received screening for colon cancer, compared with 50 percent of those in the same income range who had health insurance, and 56 percent of higher-income adults. Only about one-third – or 32 percent – of low-income uninsured women ages 40 to 64 had received a mammogram, compared with two-thirds – or 66 percent – of low-income women with health insurance and three-fourths – or 74 percent – of higher-income women.

Karen Davis, president of the Commonwealth Fund, said during the media briefing that these statistics are concerning, considering detection of breast and colon cancer at an early stage can make a significant difference in mortality.

Low- and moderate-income adults without insurance were also more likely than those in the same income bracket with health coverage to visit the emergency room because they needed a prescription – 50 percent versus 35 percent – and because they did not have a regular doctor – 41 percent versus 16 percent. Forty percent of uninsured low- and moderate income adults also said they visited the ER because other options were unaffordable.