Even small co-pay deters mammogram use

Requiring even a small co-payment dramatically reduces the likelihood that women will get regular mammograms to detect breast cancer.

Screening rates from 2001 through 2004 were nearly 11 percent lower for women who had to contribute a co-pay as low as $12, compared with women whose breast X-rays were free, researchers from Brown and Harvard universities found.

They surveyed more than 366,000 women aged 65 to 69.

"It's a surprising result," said Dr. Amal Trivedi of Brown, who led the study. "Most people would consider $12 to be a rather modest sum. But when it came to this population, co-payments as low as $12 led to a very sharp decrease in the breast cancer screening rate."

Studies have suggested that mammograms may save lives by detecting breast cancers at an earlier stage. Breast cancer is more difficult -- and more expensive -- to treat at its later stages.

"It would make clinical sense, and probably economic sense, for a health plan to eliminate a co-payment for a mammogram," Trivedi said.

Breast cancer was diagnosed in 178,000 U.S. women in 2007, and killed more than 40,000, according to the American Cancer Society, which recommends regular mammograms for women over 40.

Researchers found that mammography rates were about 4 percent lower for women living in areas where the people were poor or poorly educated, if they were required to pay part of the cost. Most plans require a $20 co-payment.

In 2001 only one woman in 200 was required to make a co-pay for a mammogram. By 2004 the ratio was 1 in 9.

The researchers reported in the New England Journal of Medicine that when patients were suddenly required to foot part of the bill, screening rates declined by 5.5 percentage points even as the rates among women in plans that continued to pay the full cost increased by 3.4 percentage points.

Dr. Peter Bach of the Memorial Sloan-Kettering Cancer Center in New York said the study "tests a fundamental presumption of the high-deductible movement -- that a knowledgeable consumer will make wise decisions when purchasing health care."