A study of Medicare patients by researchers at the Yale University School of Medicine (New Haven, Connecticut) showed an increase in the number of patients diagnosed with early-stage colon cancer — when successful treatment is most likely —after Medicare expansion of reimbursement coverage for this type of screening.

Titled “Relation Between Medicare Screening Reimbursement and Stage at Diagnosis for Older Patients With Colon Cancer,” the study was published in the Journal of the American Medical Association in December.

The paper’s conclusion:

The effect of the coverage change allowing colonoscopy as a screening tool “on proximal colon lesions suggests that increased use of whole-colon screening modalities such as colonoscopy may have played a pivotal role.”

The study is supported by the American Society of Gastrointestinal Endoscopy (Oak Brook, Illinois), whose members perform colonoscopies. The organization notes that there have been two key changes in Medicare coverage of the procedure: the policy of no coverage was changed in 1998 to coverage for patients considered at risk for the disease; and then Congress passed universal coverage in July 2001. The Yale study used these three periods in its analysis:

Period 1, no screening coverage (1992-1997); Period 2, limited coverage (1998-2001); and Period 3, universal coverage (July 2001-December 2002).

The study found that the number of patients diagnosed with colon cancer at an early stage was 22.5% in Period 1; it then increased to 25.5% in Period 2; and it increased again to 26.3% in Period 3.

The Yale researchers call their findings “robust, in that they were unchanged even after accounting for important patient and geography factors.” However, they provide the caveat that the “stage shift was primarily limited to proximal lesions,” that is, those further into the colon.

While the study results are clear, David Lieberman, MD, professor of medicine and chief of the division of gastroenterology at Oregon Health and Science University (Portland, Oregon) and a past president of ASGE, told Biomedical Business & Technology that the changes in diagnosis stage may have been affected by a “confluence of events” — such as expanded publicity about the procedure — not just the expansion of reimbursement alone.

Lieberman, for instance, was the senior author of what he called the “first and largest study” published looking at screening colonoscopy. That paper was published in 2000 in the New England Journal of Medicine. And shortly following the publication of the paper, “Today Show” television personality Katie Couric allowed airing of her own colonoscopy procedure on national TV. Then still another study supporting the procedure was published in the NEJM, Lieberman said.

“When you put the two [publications] together, what it showed was that screening colonoscopy identified patients that had lesions in the proximal area of the colon, not necessarily cancer, but advanced polyps, more effectively than the other tests that were being used, which was sigmoidoscopy and fecal occult tests,” Lieberman told BB&T.

Even among gastroenterologists, prior to 2000, “there was probably mixed opinion [on colonoscopies] in the GI community,” Lieberman said. “I think now there’s very much unanimity in the GI community that it should be the preferred screening test,” he added.