Reasons for Lack of Diagnostic Colonoscopy After Positive Result on Fecal Immunochemical Test in a Safety-Net Health System

Abstract

Background: Effective colorectal cancer screening depends on timely diagnostic evaluation in patients with abnormal results on fecal immunochemical tests (FITs). Although prior studies suggest low rates of follow-up colonoscopy, there is little information among patients in safety-net health systems and few data characterizing reasons for low follow-up rates. This study aimed to characterize factors contributing to lack of follow-up colonoscopy in a racially diverse and socioeconomically disadvantaged cohort of patients with abnormal results on FIT ("abnormal FIT" for brevity) receiving care in an integrated safety-net health system.

Methods: We performed a retrospective electronic medical record review of patients aged 50-64 years with abnormal FIT at a population-based safety-net health system between January 2010 and July 2013. Review of electronic medical records focused on patients without follow-up colonoscopy to characterize patient-, provider-, and system-level reasons for lack of diagnostic evaluation. We used logistic regression analysis to identify predictors of follow-up colonoscopy within 12 months of abnormal FIT.

Results: Of 1267 patients with abnormal FIT, 536 (42.3%) failed to undergo follow-up colonoscopy within 1 year. Failure was attributable to patient-level factors in 307 (57%) cases, provider factors in 97 (18%) cases, and system factors in 118 (22%) cases. In multivariate analysis, follow-up colonoscopy was less likely among those aged 61-64 years (odds ratio 0.63, 95% confidence interval 0.46-0.87) compared with 50-55 year olds.

Conclusions: Nearly half (42%) of patients with abnormal FIT failed to undergo follow-up colonoscopy within 1 year. Lack of diagnostic evaluation is related to a combination of patient-, provider-, and system-level factors, highlighting the need for multilevel interventions to improve follow-up colonoscopy completion rates.

Keywords: Colonoscopy; Colorectal cancer screening; Fecal immunochemical test; Randomized controlled trial; Safety-net health system.

Figure 1. Reasons for Failure to Obtain Diagnostic Colonoscopy after Abnormal FIT

Failure to complete diagnostic colonoscopy was attributable to patient-level factors in 57% of cases (blue), provider-level factors in 18% of cases (red), system-level factors in 22% of cases (green), and unknown reasons in 3% of cases.