Objectives To quantify post-colonoscopy colorectal cancer (PCCRC) rates in England by using recent World Endoscopy Organisation guidelines, compare incidence among colonoscopy providers, and explore associated factors that could benefit from quality improvement initiatives.
Design Population based cohort study.
Setting National Health Service in England between 2005 and 2013.
Population All people undergoing colonoscopy and subsequently diagnosed as having colorectal cancer up to three years after their investigation (PCCRC-3yr).
Main outcome measures National trends in incidence of PCCRC (within 6-36 months of colonoscopy), univariable and multivariable analyses to explore factors associated with occurrence, and funnel plots to measure variation among providers.
Results The overall unadjusted PCCRC-3yr rate was 7.4% (9317/126 152), which decreased from 9.0% in 2005 to 6.5% in 2013 (P<0.01). Rates were lower for colonoscopies performed under the NHS bowel cancer screening programme (593/16 640, 3.6%), while they were higher for those conducted by non-NHS providers (187/2009, 9.3%). Rates were higher in women, in older age groups, and in people with inflammatory bowel disease or diverticular disease, in those with higher comorbidity scores, and in people with previous cancers. Substantial variation in rates among colonoscopy providers remained after adjustment for case mix.
Conclusions Wide variation exists in PCCRC-3yr rates across NHS colonoscopy providers in England. The lowest incidence was seen in colonoscopies performed under the NHS bowel cancer screening programme. Quality improvement initiatives are needed to address this variation in rates and prevent colorectal cancer by enabling earlier diagnosis, removing premalignant polyps, and therefore improving outcomes.

目的使用最新的世界内窥镜检查组织指南来量化英格兰的结肠镜检查后结肠直肠癌（PCCRC）发病率，比较结肠镜检查提供者之间的发病率，并探讨可从质量改进计划中受益的相关因素。
设计基于人群的队列研究。在2005年至2013年期间在英国
设置National Health Service。
人口所有接受结肠镜检查并随后在调查后三年内被诊断为患有结肠直肠癌的人（PCCRC-3yr）。
主要观察指标PCCRC发生率的全国趋势（在结肠镜检查的6-36个月内），单变量和多变量分析以探讨与发生相关的因素，漏斗图用于测量提供者之间的差异。
结果未经校正的PCCRC-3yr总体发生率为7.4％（9317/126 152），从2005年的9.0％降至2013年的6.5％（P <0.01）。在NHS肠癌筛查计划下进行结肠镜检查的比率较低（593/16 640，3.6％），而在非NHS提供者进行结肠镜检查的比率较高（187 / 2009，9.3％）。妇女，老年人群，发炎性肠病或憩室病患者，合并症评分较高的患者以及先前患有癌症的患者的发病率较高。调整病例组合后，结肠镜检查提供者之间的比率仍存在较大差异。
结论在英格兰的NHS结肠镜检查提供者中，PCCRC-3yr率存在很大差异。在NHS肠癌筛查计划下进行的结肠镜检查中，发生率最低。需要质量改进措施来解决这种变化率并通过早期诊断，消除恶变前息肉并因此改善结局来预防结直肠癌。