Primary Care Corner with Geoffrey Modest MD: Risks of colonoscopy in older people

By: Dr. Geoffrey Modest

The medical literature has been pretty clear for the past few decades that there are significantly increased risks and decreased benefits from doing screening colonoscopy in older people. The Massachusetts Board of Registration in Medicine just published a document highlighting this point (see here).




–baseline risk of colonoscopy in general population: 4 perforations and 25 serious complications per 10,000 procedures

–patients 80-84 years old have 75% higher risk than those 65-69, overall about 1% increase per year of age; risks also increase with comorbidities (eg diabetes, stroke, CHF, COPD, atrial fibrillation).  For example, screening colonoscopies might be beneficial up to age 84 in those without comorbidities, yet benefits are uncertain in those 67-69 with >2 comorbidities.

–bowel prep is more problematic in the elderly. Harder to get a good clean-out, harder to get an adequate test, and increased need for repeat testing (and, I would imagine, higher risk of perforation based on the poor prep)

–those who have had a previous negative screen are less likely to develop adenomas/cancer, and have less need for repeat (there have been analyses done showing that the risk of cancer is much less even 15 years after a negative colonoscopy)

–one can also consider non-colonoscopy based screenings if screening is desired post age 75 (eg barium enema, CT colography, sigmoidoscopy, fecal immunochemical or DNA testing, guaiacs)

–this document also stresses informed decision-making, noting that 30% of elderly patients near the end of life may lack decision-making capacity

–the USPSTF recommends colorectal screening from age 50-75. between 75-84, the balance of risk and benefits is too small to recommend screening. over age 85, risks outweigh benefits. American College of Physicians recommends screening til age 75 and if >10 year life expectancy. ​

So, it is hard to make a strong recommendation overall for routine screening in the elderly (>75 yo), especially if they have comorbidities, given the higher risk of bad events and the lower risk of an adequate evaluation. And the studies suggesting significant benefit in the 15+ year range do support doing a final screening colonoscopy in the early 70s. One additional factor now is the insurance-driven requirement that these procedures be done as an outpatient (eg, I have had patients who need a diagnostic colonoscopy, are elderly and frail, and have been unable to get the insurer to cover a brief admission for the prep, even though a home-based prep would be exceedingly difficult and dangerous, putting the patient at risk for dehydration, hypotension, falls, etc).