Health insurance co-payments deter mammography use

Jan 24 2008

When faced with even a modest health insurance co-payment for a mammogram, significantly fewer women receive these potentially life-saving breast cancer screenings, according to a new study by Brown University and Harvard Medical School researchers.

In this large-scale investigation of the relationship between health insurance co-payments and mammography rates, researchers found that screening rates were 8 percent lower among women with a co-payment than among women with full insurance coverage. Researchers at The Warren Alpert Medical School of Brown University, with a colleague from Harvard Medical School, publish their results in the current issue of the New England Journal of Medicine.

“The message is simple and it's startling – a small co-payment for a mammogram can lead to a sharp decrease in breast cancer screening rates,” said Amal Trivedi, M.D., lead author of the study and assistant professor in the Department of Community Health at Alpert Medical School. “Co-payments as low as $12 deter women from getting mammograms. Because mammograms are critical in the fight against breast cancer, the most common cancer among American women, our findings have important health policy implications.”

“Eliminating co-payments for mammograms in the Medicare program has the potential to save lives, because screening detects breast cancers at an earlier, more curable stage,” said John Ayanian, M.D., study co-author and professor of medicine and health care policy at Harvard Medical School and Brigham and Women's Hospital.

The effect of insurance co-payments, or consumer cost sharing, on health care use and spending is a topic of intense interest for health policy-makers and researchers. But recent long-term data on the consequences of cost sharing, like deductibles and co-pays are limited. For example, results of the RAND Health Insurance Experiment, a watershed study of cost sharing and its impact on health, were released in 1982.

Trivedi wanted to gather and analyze more recent data because cost sharing is on the rise. According to a 2006 survey by the Henry J. Kaiser Family Foundation and the Health Research and Educational Trust, the most common co-payment for a medical office visit has doubled since 2001 while deductibles have increased an average of 60 percent in employer-based plans.

Trivedi chose to study mammography because the benefits of these X-ray photographs of the breast are widely accepted. The American Cancer Society, for example, recommends that women over 40 get annual mammograms to increase the odds of early breast cancer detection and treatment. Trivedi chose Medicare managed-care health insurance plans for review because the team could study a large number of patients over time.

In their study, Trivedi and colleagues studied coverage for mammography within 174 Medicare managed-care plans from 2001 to 2004. The review included 366,475 women between the ages of 65 and 69 living in 38 states.

The team compared the rates of biennial breast cancer screening within plans requiring co-payments with screening rates for plans with full coverage. They also analyzed data from plans that introduced co-payments over the three-year study period in order to study how mammography rates would change compared to rates in plans without co-payments.

Trivedi and his team found that:

• biennial breast cancer screening rates were 8 to 11 percent lower in cost-sharing plans – a difference that persisted even when adjusting for possible differences due to income, education, race and other factors;
• from 2002 to 2004, screening rates decreased by 6 percent in plans that introduced co-payments while screening rates increased by 3 percent in matched control plans that retained full coverage;
• the number of plans with cost sharing for mammography grew from three to 21 between 2001 and 2004, affecting .5 percent of women in 2001 and 11 percent of women by 2004;
• in cost sharing plans, the range of co-payments for a mammogram was $12.50 to $35, with an average co-payment of $20.

“We've isolated the effect of co-payments on an important preventive health measure,” Trivedi said. “Mammograms are an essential service for older women, yet many women avoid that service when they are required to pay out-of-pocket. By eliminating co-payments for mammograms, we could get more women tested. More testing would mean earlier breast cancer treatment and improved chances for breast cancer survival.”