MONDAY, Aug. 29 (HealthDay News) -- Although older Americans have many Medicare options to choose from, they may not be making good decisions about their coverage, according to a new study.

Some seniors -- particularly those with impaired brain function -- can become overwhelmed by the variety of complex Medicare Advantage plans available to them, preventing them from finding the best plan to fit their needs, according to researchers from Harvard Medical School's department of health care policy.

"We are providing the most complex insurance choices to the very population that is least equipped to make these high-stakes decisions," said Dr. J. Michael McWilliams, assistant professor of health care policy and medicine at Harvard Medical School and a general internist at Brigham and Women's Hospital, in a university news release.

"Most other Americans choose from just a few health plans, but elderly Medicare beneficiaries often have to sift through dozens of options," McWilliams said.

The Medicare Modernization Act of 2003 increased the number of private plans participating in the Medicare Advantage program, which purports to usher in more competition, lower premiums and result in better benefits, including prescription drug coverage.

In assessing how these changes affected enrollment in Medicare Advantage compared to traditional Medicare, researchers examined nearly 22,000 enrollment decisions made by more than 6,600 participants over the course of four years, taking into account their mental status and the plans available to them.

The study, published online and in the September print issue of Health Affairs, found that enrollment in Medicare Advantage increased when the number of Medicare Advantage plans available to seniors was fewer than 15.

When there were more than 30 plans available, however, enrollment dropped. The researchers pointed out that 25 percent of U.S. counties offer more than 30 Medicare Advantage options.

Elderly people with impaired brain function were much less likely to understand and take advantage of the wide array of benefits offered by Medicare Advantage plans and instead were more likely to choose the traditional Medicare program by default, according to the report.

Given the increasing numbers of older Americans with Alzheimer's and other forms of dementia, the findings should prompt policymakers to establish better ways to assist seniors in making the right choice for them, researchers said. That could include offering fewer choices or helping them make better decisions based on those options.

"Efforts to limit choice and guide seniors to the most valuable options could especially benefit those with cognitive impairments, who without more help appear to be leaving money on the table," said McWilliams. "Better enrollment decisions could in turn strengthen competition by rewarding high-value plans with more enrollees."

Not all experts would agree that the seniors who chose Medicare over Medicare Advantage were making the wrong choice, however.

Medicare Advantage plans have serious drawbacks compared to the original Medicare, according to the Medicare Rights Center (MRC), a non-profit consumer advocacy group.

Among the problems with Medicare Advantage the MRC cites are higher costs for skilled nursing care, home health care and in-patient hospital costs; unstable private plans that may suddenly stop coverage; restrictions in the choice of doctors, hospitals and other providers members can choose; and problems getting urgent or emergency care.

More information

The U.S. National Institutes of Health provides more information on Medicare.