Appropriateness of the Indication for Colonoscopy: Systematic Review and Meta-analysis

Background & Aims: Application of appropriate indications for colonoscopy (OC) should conserve limited endoscopic resources. To perform a systematic review and meta-analysis to assess the accuracy of ASGE and EPAGE guidelines in selecting patients referred for OC, relative to the detection of neoplastic and non-neoplastic relevant endoscopic findings. Methods: Studies comparing the appropriateness of OC indication according to ASGE or EPAGE guidelines and the detection of cancer, adenomas, and benign relevant endoscopic findings were identified, by searching MEDLINE (1982 - June 2009). Predefined outputs of the meta-analysis were sensitivity, specificity, positive and negative likelihood ratios (LR+, LR-), and the diagnostic odds ratio (DOR). Results: We included twelve cohort studies comprising 14,160 patients; 10,056 OC indications were categorized as appropriate, and 3,522 (26%) as inappropriate. For cancer detection, the weighted sensitivity, specificity, LR+, LR- and DOR were 89% (95% CI, 82-93%), 26% (95% CI, 21-31%), 1.2(95% CI, 1.1-1.3), 0.45 (95% CI, 03-0.7), and 3 (95% CI, 1-5), respectively. For adenomas, the adjusted sensitivity, specificity, LR+, LR- and DOR were 85% (95% CI, 77-91%), 27% (95% CI, 22-32%), 1.14 (95% CI, 1-1.2), 0.6 (95% CI, 0.4-0.9), and 1.9 (95% CI, 1.2, 2.9), being for relevant findings equal to 89% (95% CI, 82-93%), 26% (95% CI, 21-31%), 1.16(95% CI, 1-1.3), 0.44(95% CI, 0.25-0.8), and 2.6 (95% CI, 1.2-5.6). Conclusions: Appropriateness guidelines appeared to have a suboptimal sensitivity and a poor specificity for colorectal cancer, being also characterized by a similar accuracy for the diagnosis of benign relevant endoscopic findings. Better strategies are required to select patients with significant pathology for OC.