We would like to thank Stjepan Škudar for his thoughtful comments 1 regarding our analysis of Faecal Immunochemical Testing (FIT) and symptomatic colonoscopy, using data from the UK National Endoscopy Database (NED) 2. We agree that a limitation of using endoscopy-derived data is the absence of information on patients who were referred but did not ultimately undergo endoscopic assessment. This has the potential to introduce selection bias. However, patients with a negative FIT who nevertheless proceeded to colonoscopy were likely to represent a clinically higher-risk subgroup, suggesting that the observed diagnostic yield among FIT-negative colonoscopies may overestimate rather than underestimate the underlying risk within the wider FIT-negative symptomatic population. We also acknowledge the incomplete recording of FIT results within NED, reflecting the realities of routine national data capture during a period of evolving FIT implementation. Although this remains an important limitation, we do not believe it is likely to have introduced substantial bias, as the demographics and diagnostic yields of the ‘FIT not recorded’ group are fully presented in table 1 and were broadly consistent with expected symptomatic colonoscopy populations. We agree that appropriate safety-netting and ongoing audit are essential components of any FIT-based triage pathway. However, our analysis demonstrated that FIT is not only a strong predictor of colorectal cancer risk, but also one of the strongest available predictors of large-polyp detection. We also agree with the correspondents' comments regarding inflammatory bowel disease (IBD). As discussed in the original manuscript, where IBD is clinically suspected, more appropriate investigations such as faecal calprotectin should be considered, since although FIT positivity is associated with increased IBD risk, the negative predictive value of FIT is insufficient for use as a rule-out test. We agree that future studies linking referral pathways, FIT results, endoscopic findings and cancer registry outcomes would provide important complementary evidence regarding pathway-level safety and interval cancer risk. Nevertheless, we believe our findings remain clinically important in demonstrating the marked variation in diagnostic yield according to FIT level across a very large real-world symptomatic colonoscopy cohort. The authors' declarations of personal and financial interests are unchanged from those in the original article 2. Linda Sharp: writing – review and editing. Mahmoud Mohamed: writing – review and editing. David Beaton: writing – original draft, writing – review and editing. Keith Pohl: writing – review and editing. Matthew Rutter: writing – original draft, writing – review and editing. The authors have nothing to report. This article is linked to Beaton et al. papers. To view these articles, visit https://doi.org/10.1111/apt.70537 and https://doi.org/10.1111/apt.70739. The data that support the findings of this study are available from the corresponding author upon reasonable request.
Beaton et al. (Tue,) studied this question.