Abstract

Introduction: Gastrointestinal symptoms correlate poorly with cancer diagnosis. A Faecal
Immunochemical Test (FIT) result of ≥10μg has high sensitivity and negative predictive value for
colorectal cancer (CRC) detection. A FIT-based diagnostic pathway may lead to more effective
resource utilisation. We aimed to use National Endoscopy Database (NED) data to create a new
colonoscopy performance measure, cancer detection rate (CDR) to assess the appropriate
identification of target populations for colonoscopy; then to use CDR to assess the impact of
implementing a FIT-based referral pathway locally.
Methods: NED data was analysed to compare local diagnostic colonoscopic CDR in 2019 (pre�pathway revision) and 2021 (post-pathway revision), benchmarked against overall national CDR for
the same timeframes.
Results: 1,123,624 NED diagnostic colonoscopies were analysed. Locally, there was a significant
increase in CDR between 2019 and 2021, from 3.01%[2.45–3.47%] to 4.32%[3.69–4.95%],p=0.003.
The CDR increase was due to both a 10% increase in the number of colorectal cancers detected and
a 25% reduction in the number of diagnostic colonoscopies performed. Nationally, there was a
smaller, but significant, increase in CDR from 2.02%[1.99 – 2.07%] to 2.33%[2.29 – 2.37%],p<0.001.
The rate of increase in CDR% between 2019 and 2021 was significantly different locally compared to
nationally.
Conclusion: Our study indicates that the introduction of a robustly-vetted FIT-based algorithm to
determine whether diagnostic colonoscopy is required, is effective in increasing the colonoscopic
CDR. Moreover, CDR appears to be a meaningful performance metric that can be automatically
calculated through NED, enabling monitoring of the quality of referral and vetting pathways.