Background and Aims: There is still considerable controversy surrounding the relationship between fatigue of endoscopists and the quality of colonoscopy. The aim of this study is to comprehensively explore the association between fatigue and adenoma detection rate (ADR) and cecal intubation rate (CIR).

Methods: The mixed effects logistic regression model was used to explore the relationship between fatigue- related factors including procedure order, session of procedures and the day of week and ADR as well as CIR.

Results: When controlling for confounders, the day of week (Monday as reference, Friday, p=0.022; weekends, p=0.015) and session of procedures (P<0.001) were significantly associated with ADR while procedure order (<5 as reference, 6-10, p<0.001; >10, p=0.001) and session of procedures (p=0.004) were independent predictors for CIR. Additionally, there was a significant downward trend on ADR and CIR with the approaching of weekends (p=0.005) and increasing procedure orders (p<0.001), respectively. In the subgroup analysis stratified by gender, age and workload intensity, significant lower ADR was found in the afternoon in all subgroups (male, p<0.001; female, p=0.005; <40 years, p<0.001; ≥40 years, p=0.020; intensity<50 per month, p=0.017; intensity≥50 per month, p<0.001) but the downward trend on ADR as the week progressed was only found in endoscopists with male gender (p=0.011), age<40 (p=0.027) and high workload intensity (p=0.003). Moreover, a significant downward trend on CIR as the procedure order increased was found in all subgroups except endoscopists with age≥40 (male, p=0.005; female, p<0.001; <40 years, p<0.001; intensity<50 per month, p=0.001; intensity≥50 per month, p<0.001).

Conclusions: Colonoscopies in the afternoon will affect ADR negatively while increasing procedure order will cause a lower CIR. Importantly, the significant negative influence of Friday and weekends on ADR was first discovered in this study. Moreover, endoscopists with female gender and advanced age (≥40) but not high workload intensity showed superiority in resistance of fatigue caused by the end of the week and increasing daily procedures.


fatigue, colonoscopy quality, adenoma detection rate, cecal intubation rate, screening colonoscopy