Predictors of failed colonoscopy in nonagenarians: a single-center experience

Data on the yield of conventional colonoscopy in very old patients remain limited. The aim of the study was to evaluate the outcome of colonoscopy in nonagenarian patients.

The safety, success rate to complete colonoscopy and findings of colonoscopies performed during the last 5 years in our center were compared between 41 nonagenarians (group 1) and 2 control groups: 50 consecutive patients aged 70 to 79 years (group 2) and 50 consecutive patients aged 50 to 59 years (group 3). Serum hemoglobin, albumin, patients' source, indications for and colonoscopies findings were retrieved for the total study cohort and comorbidities, mental and functional states for group 1 only. Reasons for colonoscopy failure and predictive factors for failed colonoscopy were analyzed. Chi-square test was used to detect differences in categorical variables by failure or age group. Failure was modeled using logistic regression analyses, and odds ratios with 95% confidence intervals were calculated. All tests were 2-sided and considered significant at P<0.05.

Failed colonoscopy was significantly more prevalent in group 1. The main reason for it was bad preparation. Malignant tumors were significantly more frequently observed in the elderly (groups 1 and 2) than in the younger age group. No complications during and 48 hours postcolonoscopy were observed in all study participants. In univariate analyses in group 1 mental and functional states were inversely and low serum hemoglobin and albumin levels were positively, significantly associated with failure to complete colonoscopy. In multivariate logistic regression analyses, only functional state retained significance as a predictor of failed colonoscopy (odds ratio 5.6, 95% confidence interval 1.5-21.06, P=0.01).

Colonoscopy in nonagenarians is a safe procedure; however, it carries a significantly higher failure rate. Functional decline was found to be a significant predictive factor for failed colonoscopy.