The expansion of Medicare in 1998 to cover colonoscopies appears to have led to both an increase in demand for the screening procedure and a rise in early-stage colon cancer diagnoses, according to a study by Yale researchers.

“We found that after the Medicare policy change, the use of colonoscopies went up and there was a corresponding increase in the likelihood that patients with colon cancer would be diagnosed at an early, curable stage,” said lead investigator Cary P. Gross, M.D., associate professor of medicine. His study appeared in the December 20 issue of JAMA: The Journal of the American Medical Association.

In 1998 the Medicare reimbursement policy was changed to cover the procedure, which costs roughly $800, for older patients with increased colon cancer risk. The policy was expanded again in 2001 to cover colonoscopy screenings for everyone 65 and older.

As a general internist at the Primary Care Center at Yale-New Haven Hospital, Gross sees firsthand how reluctant patients are to undergo a colonoscopy. “I thought it was important to test the assumption that reimbursement had been a major barrier to obtaining a colonoscopy,” he said.

The researchers studied patients in the Surveillance, Epidemiology and End Results Medicare-linked database between 1992 and 2002. They adjusted for such factors as the increasing awareness of colon cancer screening during the study period, given the high-profile efforts of TV anchorwoman Katie Couric to draw attention to the importance of the procedure with an on-air colonoscopy in March 2000. (Couric’s husband had died of colon cancer two years earlier.)

Gross’ team found that the new Medicare policies were associated with a substantial increase in colonoscopy use among beneficiaries without cancer, as well as an increased likelihood of early diagnosis for patients who developed cancer. Before Medicare started covering the screening procedure, 22.5 percent of Medicare beneficiaries who developed colon cancer were diagnosed at an early stage. After Medicare began providing coverage for older at-risk patients, that number rose to 25.5 percent. When coverage was expanded again, to include all Medicare recipients over 65, 26.3 percent of patients diagnosed with colon cancer were diagnosed at an early stage.

“Our analysis suggests that the new Medicare policy was associated with improved health by identifying more patients with early-stage disease,” Gross said. But he was quick to add that, despite these encouraging signs, nearly three-quarters of all patients diagnosed with colon cancer still receive the diagnosis after the disease has spread beyond the early stage. Although his study suggests that cost had been a barrier for some patients, Gross said it also showed that “the new reimbursement policy was not a sufficient intervention to alter the decision process about having a colonoscopy for many older people.”

Noting that colonoscopies can also prevent colon cancer by removing precancerous lesions, Gross said the next step is to assess the impact of Medicare colonoscopy reimbursement on the incidence of colon cancer and to develop strategies to increase the use of screening colonoscopies at the population level.