Impact of cumulative experience on the quality of screening colonoscopy: A 13-year observational study

To investigate trends in quality of screening colonoscopy (using the Global Rating Score) in the 13 years since introduction of the Bowel Cancer Screening Programme in England.

An English Bowel Cancer Screening Programme colonoscopy service from 2007 to 2019.

A retrospective observational study was undertaken using a prospectively collected database in order to analyse trends in screening endoscopies (including patients following positive faecal occult blood test or with high-risk findings on flexible sigmoidoscopy). The Global Rating Score quality indicators for Bowel Cancer Screening Programme colonoscopy were used as outcome measures, and trends over time were analysed. These included caecal intubation rate, adenoma detection rate, colorectal cancer detection rate, proportion of patients with minimal or mild discomfort scores, proportion of patients who required intravenous sedation, and adverse events.

There were 5352 colonoscopies included, performed by 3 endoscopists; 73.8% were index procedures (i.e. first Bowel Cancer Screening Programme colonoscopy) and the remainder were follow-up or surveillance colonoscopies. The mean age of patients was 66 (standard deviation 5) years, and 59.8% were male. Mean age increased over time (R²=0.033; p < 0.001). There were significant trends over time towards higher caecal intubation rate (p = 0.015), higher adenoma detection rate (p < 0.001), lower proportion requiring intravenous sedation (p < 0.001). There were no significant trends in comfort scores (p = 0.606), adverse events (p = 0.503) or colorectal cancer detection (p = 0.089).

There was a consistent improvement in the Global Rating Score for Bowel Cancer Screening Programme colonoscopies since the start of the programme, even when quality was already high at the start. Patients can expect high-quality colonoscopy when participating in the Bowel Cancer Screening Programme.