Mo1714 – Effectiveness of Phone Prompt Prior to Mailed Fecal Immunochemical Test (FIT) Outreach for Patients with Previous Negative Fit: A Randomized Controlled Trial

10 mm) or by type of serrated lesion (sessile serrated adenoma/polyp (SSA/P) with dysplasia, traditional serrated adenoma, and SSA/P ≥ 10 mm) and accounted for a combination of a high-risk adenomatous and serrated lesion in the same patient.The initial and surveillance colonoscopy summary statistics were tabulated and the proportions of patients with high risk and interval CRC's were calculated.Results: There were 17,351 colonoscopies done for FIT positive patients with 3,488 (20.5%) patients having at least one HRP removed.Of the patients with a HRP at index colonoscopy, 2,184 (59.7%) underwent at least one surveillance colonoscopy during the study period.These patients were 56.6% male and had a median age of 63 years (10 th , 90 th percentile: 53, 72).The median time to surveillance colonoscopy was 37.1 months (10 th , 90 th percentile: 11.7, 42.9).Thirteen CRCs and 336 HRPs were discovered at surveillance colonoscopy.The proportion of surveillance colonoscopies with either a CRC or HRP ranged from 12% in patients who had an adenoma with HGD on the index colonoscopy to 16.4% in patients who had an adenoma ≥ 10 mm on the index colonoscopy (Table 1).For serrated lesions, 8.3% of patients with a serrated polyp with dysplasia at index colonoscopy had a subsequent CRC or HRP compared to 20.9% of patients who had a SSA/P > 10mm on the index colonoscopy.Of patients with both a high risk serrated and adenomatous polyp, 13/95 (13.7%) had a CRC or HRP at surveillance colonoscopy.Conclusions: Patients with a large adenoma or SSA/P at index colonoscopy appeared to be more likely to have another HRP or CRC at surveillance colonoscopy.Further regression analyses to confirm this possible association are planned.