Differences in screening vs non-screening colonoscopy: scope for improvement?

Colonoscopy performed as part of the NHS Bowel Cancer Screening Programme (BCSP) is of high standard as measured using global rating scale (GRS) criteria. Screening practitioners also provide a non-screening colonoscopy service. The current study compares colonoscopy quality indicators between screening and non-screening groups performed by a single practitioner using the GRS.

Patient details were obtained for all consecutive colonoscopies between 2007 and 2014 performed by a single screening practitioner. Data were collected retrospectively from electronic patient records; BCSP Exeter database and non-screening colonoscopies were compared. Data included patient demographics (age, gender), sedation, and the GRS data including caecal intubation, adenoma and neoplasia detection rates.

In all, 1961 colonoscopy procedures (1067 screening and 894 non-screening) were identified; 57% were men. Mean (SD) age for all patients was 64 (± 10.4) years. Non-screening patients were younger [62 (± 14) vs 66 (± 4.8) years; P < 0.05] and were less likely to be men (51.5% vs 61.9%; P < 0.05) than their screening counterparts. Caecal intubation was more successful in screening patients [1027/1067 (96.3%)] than non-screening patients [805/894 (90%)]; P < 0.05. Adenoma detection rate was higher in the screening (46.8 ± 4.4) than non-screening (26.3 ± 11.8) group; P < 0.05. There were no differences in neoplasia detection. Polypectomy was more likely (55.5% vs 30.2%) and polyp retrieval more successful (97.5% vs 86.7%) in the screening group.

Screening and non-screening colonoscopy differ in the GRS domains of completion and pathology detection. These differences need to be acknowledged when comparing screeners and non-screeners using GRS within units.