Effect of simply recording colonoscopy withdrawal time on polyp and adenoma detection rates

According to national recommendations, colonoscopy withdrawal time (WT) on negative screening examinations should average more than 6 minutes because this time is associated with a higher rate of polyp detection. Attempts have been made to increase the WT; however, simply knowing that a quality measure, such as the WT, is being monitored, by itself, may improve the quality of an examination.

To measure changes in the polyp detection rate associated with recording the WT.

Retrospective.

Single tertiary care center.

Patients undergoing colonoscopy within 5 months immediately before (group A) and after (group B) initiation of WT recording. Colonoscopies were excluded if procedure times were incomplete, missing, or nonsensical.

Polyp detection, compared by using the chi(2) test and logistic regression multivariate analyses; pathology manually reviewed from a sample of 200 consecutive polyp cases (100 per group).

The average WT in group B was 14.5 minutes (11.0 minutes in negative screening examinations). In group A, polyps were detected in 530 (37.7%) of 1405 colonoscopies compared with 571 (41.2%) of 1387 colonoscopies in group B (difference 3.5%; 95% CI, -0.2% to 7.1%), a nonsignificant 9.3% relative increase. Longer procedure time, age, sex, and indication were significant predictors; monitoring the WT was not. Nonsignificantly, more polyp examinations in group B found all nonadenomas compared with group A (36% vs 27%; P = .17), and polyps were nonsignificantly smaller (P = .30).

Retrospective database data, pathology performed only on a subsample.

WT recording was associated with a nonsignificant increase in polyp detection, but this was likely attributable to a slight increase in the detection of (smaller) nonadenomatous polyps.