Development of a Multivariable Prediction Model to Identify Patients Unlikely to Complete a Colonoscopy Following an Abnormal FIT Test in Community Clinics
Abstract Background Colorectal cancer (CRC) is the 2nd leading cancer killer in the US. The Strategies and Opportunities to STOP Colon Cancer in Priority Populations (STOP CRC) project aimed to increase CRC screening among patients in Federally Qualified Health Centers (FQHCs) through a mailed fecal immunochemical test (FIT) outreach program. However, rates of completion of the follow-up colonoscopy following an abnormal FIT remain low. We developed a multivariable prediction model using data available in the electronic health record to assess the probability of patients obtaining a colonoscopy following an abnormal FIT test.Methods We used Cox regression to develop a risk prediction model among a retrospective cohort of patients with an abnormal FIT result and a year of follow-up data.Results Of 1723 patients with an abnormal FIT result, 699 (40.6%) had a colonoscopy within 1 year and 597 (34.6%) had a recorded colonoscopy within 6 months. The model shows adequate separation of patients across risk levels for non-adherence to follow-up colonoscopy (bootstrap-corrected C-statistic > 0.63). The refined model included 8 variables: age, race, insurance, GINI income inequality, long term anticoagulant use, receipt of a flu vaccine in the past year, frequency of missed clinic appointments, and clinic site. Probability of obtaining a follow-up colonoscopy within 6 months varied across quintiles; patients in the lowest quintile had an estimated 18% chance, whereas patients in the top quintile had a greater than 55% chance of obtaining a follow-up colonoscopy.Conclusions Knowing who may be at risk for failing to follow-up on an abnormal FIT test could help identify patients in need of early interventions aimed at completing a colonoscopy.Trial registry This trial was registered at ClinicalTrials.gov (NCT01742065) on December 5, 2012.