Appropriateness of the indication for colonoscopy: is the endoscopist the 'gold standard'?

The appropriate selection of patients for colonoscopy is crucial for an efficient use of endoscopy. The role of endoscopist in filtering out inappropriate referrals is largely unknown.

A multicentre, prospective study was performed in which consecutive patients referred for colonoscopy during a 1-month period were enrolled. Before colonoscopy, the endoscopist assessed appropriateness of the endoscopic referral without directly consulting official guidelines, also collecting clinical and demographic variables. Appropriateness of the indication was eventually assessed by a group of experts based on the American Society for Gastrointestinal Endoscopy guidelines, representing the gold standard. Outcomes of the study were the inappropriateness rate and the main related causes, as well as the concordance rate between the endoscopists and the experts. A multivariate analysis was performed to identify predictors of inappropriateness.

One thousand seven hundred ninety-nine patients were enrolled in 20 centres, of which 1489 outpatients were included in the final analysis. According to the American Society for Gastrointestinal Endoscopy guidelines, 432 referrals were inappropriate, corresponding to an inappropriateness rate of 29%. At multivariate analysis, prescription of a repeated colonoscopy (≥2 colonoscopies in the same patient) was strongly associated with the inappropriateness of the indication (odds ratio: 8.8; 95% confidence interval: 6.2, 12.7). Postpolypectomy or post-colorectal cancer surveillance accounted for 77% of the inappropriate control procedures. A 79% concordance rate between endoscopist and expert assessment was found. Among the 317 discordant cases, postpolypectomy or post-colorectal cancer surveillance accounted for 51% of the cases, the endoscopists mistakenly classifying it as appropriate in 55% to 61% of the inappropriate cases.

Inappropriateness in outpatient colonoscopy referrals remains high, surveillance procedures representing the most frequent source of inappropriateness.