Vital Signs: Screenings: When It’s Too Soon for a New Colonoscopy

While many uninsured patients cannot afford to undergo colonoscopy screening as often as they should, a new study suggests many older Medicare beneficiaries receive the colon cancer test too often.

In a sample of 24,000 Medicare beneficiaries 66 and older, almost half of those who had a normal colonoscopy between 2001 and 2003 underwent a repeat exam within seven years, instead of waiting the recommended 10 years, researchers reported in a study published online on May 9 in Archives of Internal Medicine.

Yet, 42 percent of those repeat patients had no symptoms indicating another screen had been necessary — meaning that almost one in four had a second colonoscopy for no apparent reason.

Although current guidelines recommend against routine screening after age 75, the researchers found that many patients in their late 70s and 80s with a normal test also repeated it within seven years.

With rare exceptions, the costs, nearly $1,000 per colonoscopy, were paid by Medicare.

Colonoscopies do pose some small risks, including perforation of the colon. “This screen is not benign,” said Dr. James S. Goodwin, the study’s lead author. “When you do it every 10 years, the benefit far outweighs any potential harm. But you get no added benefit by screening every five years, and you double the harm.”