Healthcare economists have a fixation on various ratios that determine when, and if, a diagnostic procedure should be done. Two such ratios used frequently are the risk-benefit ratio and the cost-benefit ratio. The United States Preventive Services Task Force, the USPSTF, employs these all the time when deciding if a screening procedure is worth the cost or worth the risk.
One place where these ratios are front and center is in deciding if a colonoscopy should be done after age 75. This is a subject that produces opinions that vary widely. Frequent studies have been done to try to establish a norm that everyone could live by, but results differ and a clear cut guideline is hard to establish.
My personal opinion is the cost is worth it. Doctors and their patients can learn so much from a colonoscopy in an older patient, that to me the cost of the procedure is justified. A colonoscopy does involve risk because the patient must be sedated, and the elderly don’t always tolerate that very well. There’s a greater risk of perforation of the colon during the procedure, and most folks over 75 have another medical condition (co-morbidity) that increases their chances of problems.
Life expectancy continues to rise (despite temporary declines due to opioid deaths) with “men averaging 80.3 years and women 85.9 years.” Nearly “1 in 2 colorectal cancer cases is diagnosed after age 75, with the incidence steadily increasing in this age group.” That is an important number because when nearly half the cases of colorectal cancer are diagnosed after age 75, why aren’t we recommending colonoscopy after that age.
Well, the reason lies in a concept called frailty. This is an assessment of an elderly patient’s overall health, physical well-being, and relevance of existing co-morbidities, eg. diabetes, heart disease, neurologic disorders. The frailty index is used to identify patients considered for colonoscopy who might be “vulnerable to complications and least likely to benefit” from the procedure. A high frailty index says the patient’s “risk of death from another cause substantially outweigh(ed)s the risk for death from colorectal cancer.” Those patients would not be candidates for colonoscopy.
On the other hand, a study from Australia found advanced cancers in more than one third of patients over 75 who were having follow-up colonoscopies, and a US study of over 56K patients over 75 showed colonoscopy significantly reduced the incidence of colorectal cancer and death from it. Patients who had normal colonoscopies during the 10 years before age 75 and had no family history of CRC were overwhelmingly negative at repeat colonoscopy.
So whether a patient over 75 needs a colonoscopy should be decided on a case by case basis taking into account the frailty index, the risk for complications both procedural and anesthesia-related, and the likelihood of co-morbid complications. Patients with a history of CRC are not in this group. They follow an established protocol ignoring age, unless something else precludes standard follow-up.
In today’s world, 75 isn’t always old. A lot of people exercise, eat right, aren’t obese, and don’t smoke. They tend to be the healthier of this age group. I think they should have a colonoscopy because CRC is still a possibility. A patient who has smoked, is diabetic, or has known heart disease would be taking a big risk to have a colonoscopy. But, really, the latter patient may actually have a greater risk for CRC because his negative lifestyle. So individualized decisions should be made, and it shouldn’t be that difficult.
Reference: Beorchia S. Colonoscopy Beyond 75: Are Risks Outweighing Benefits medscape.com 2026 May 18.
