Initiatives to increase colonoscopy capacity - is there an impact on polyp detection? A UK National Endoscopy Database analysis.

Background:  To address mismatch between routine endoscopy capacity and demand, centers often implement initiatives to increase capacity, such as weekend working or using locums/agency staff (insourcing). However, there are concerns that such initiatives may negatively impact quality. We investigated polyp detection for weekend vs. weekday and insourced vs. standard procedures using data from the UK National Endoscopy Database.

Methods:  We conducted a national, retrospective, cross-sectional study of diagnostic colonoscopies performed during 01/01-04/04/2019. The primary outcome was mean number of polyps (MNP) and the secondary outcome was polyp detection rate (PDR). Multi-level mixed-effect regression, fitting endoscopist as a random effect, was used to examine associations between procedure day (weekend/weekday) and type (insourced/standard) and these outcomes, adjusting for patient age, sex, and indication.

Results:  92 879 colonoscopies (weekends: 19 977 [21.5 %]; insourced: 9909 [10.7 %]) were performed by 2496 endoscopists. For weekend colonoscopies, patients were less often male or undergoing screening-related procedures; for insourced colonoscopies, patients were younger and less often undergoing screening-related procedures (all P < 0.05). Fully adjusted MNP was significantly lower for weekend vs. weekday (incidence rate ratio [IRR] 0.86 [95 %CI 0.83-0.89]) and for insourced vs. standard procedures (IRR 0.91 [95 %CI 0.87-0.95]). MNP was highest for weekday standard procedures and lowest for weekend insourced procedures; there was no interaction between procedure day and type. Similar associations were found for PDR.

Conclusions:  Strategies to increase colonoscopy capacity may negatively impact polyp detection and should be monitored for quality. Reasons for this unwarranted variation require investigation.