Simple Prediction Model for Colorectal Serrated Polyps: Development and External Validation Study in US Prospective Cohorts.

Serrated polyps (SPs) are precursors for colorectal cancer (CRC) and contribute disproportionately to post-colonoscopy cancers. Leveraging three US cohorts (43974 women and 5322 men), we developed prediction models for high-risk SPs (sized ≥10 mm or ≥3) among individuals undergoing their first colonoscopy screening. We then validated the model in the Partners Colonoscopy Cohort (51203 women and 39077 men). We evaluated discrimination and calibration using the C-statistic and Hosmer-Lemeshow test, respectively. The age & family history model generated a C-statistic (95% CI) of 0.57 (0.56-0.58) in women and 0.58 (0.55-0.61) in men. Further inclusion of smoking, alcohol, and body mass index (the simple model) increased the C-statistic (95% CI) to 0.68 (0.67-0.69) in women and 0.68 (0.66-0.71) in men (all P<0.001). Adding more predictors did not provide much incremental predictivity. In the validation cohort, moderate discrimination was observed in both women (0.60, 0.58-0.61) and men (0.60, 0.59-0.62). Notably, the simple model also yielded similar C-statistics for a composite endpoint of SPs and high-risk conventional adenomas (HRAs) (women, 0.62, 0.62-0.63; men, 0.63, 0.61-0.64). The model was adequately calibrated in both sets of cohorts. In summary, we developed and externally validated a simple prediction model based on five major risk factors for high-risk SPs that may be useful for healthy lifestyle recommendations and tailored CRC screening.