Influence of Comorbidities on Colorectal Cancer Screening Participation and Mortality.

Aims: Organized screening programs improve colorectal cancer (CRC) screening participation, but outreach services can be improved. We sought to understand screening deferral by examining patient-level factors and how they relate to fecal immunochemical test (FIT) orders, completion rates, and long-term mortality. Methods: Patients aged 50-75 years who were not up to date with CRC screening receiving usual care were followed over time (NCT02613260). Patient-level laboratory and cancer registry data were used to identify patients who met a specified laboratory threshold: albumin < 3 g/dL, HIV viral load > 10,000 copies or CD4 < 200 cells/µL, creatinine > 4 mg/dL, platelets < 100,000/µL, total bilirubin > 4 µmol/L, NH3 > 20, positive urine amphetamine or cocaine, serum ethanol > 80, hemoglobin A1C > 10%, and stage 3 or 4 cancer. The proportion of patients with a FIT order, FIT completion in 1-year, and mortality at 8-years were compared in patents with and without the lab abnormality. Results: Nine thousand six hundred seventy-six patients were eligible for screening, of which 1053 met the criteria for laboratory abnormalities. Patients with laboratory abnormalities were less likely to have a FIT order placed (39.5% vs 66.8%, Conclusions: Patients with laboratory abnormalities were less likely to have a FIT order placed and completed, and experienced higher mortality, suggesting that screening was deferred by providers. Future studies should gather provider input to understand how patient-level electronic data could be considered in the implementation of screening services.