Barriers to Follow-Up Colonoscopy After Positive FIT or Multitarget Stool DNA Testing

Fecal immunochemical testing (FIT) and multi-target stool DNA testing (mt-sDNA) are recommended colorectal cancer screening options but require follow-up with colonoscopy to determine the source of a positive result. We performed a retrospective analysis in an academic health system to determine adherence to colonoscopy in these patients.

We identified all patients aged 40 years and older with at least 1 primary care visit who had a positive FIT or mt-sDNA between January 2016 and June 2018. We identified receipt of colonoscopy within 6 months of the positive test and reviewed medical records to determine reasons for lack of colonoscopy.

We identified 308 eligible patients with positive FIT and 323 with positive mt-sDNA. Some patients with positive FIT (46.7%) and patients with positive mt-sDNA (71.5%) underwent colonoscopy within 6 months, and time to colonoscopy was also shorter with mt-sDNA (hazard ratio, 1.83; 95% CI, 1.48-2.25). These differences remained in a multivariable model adjusting for patient characteristics. Among patients without colonoscopy after positive FIT, 1 or more system, provider, and patient-related barriers were identified in 32.1%, 57.6%, and 36.3%, respectively. Among patients without colonoscopy after positive mt-sDNA, corresponding frequencies were 30.4%, 43.5%, and 57.6%, respectively.

Follow-up colonoscopy was higher for mt-sDNA than FIT, which could be due in part to preselection by clinicians and/or patients. Among patients who did not follow-up, provider and system factors were as frequently encountered as patient factors. These findings reinforce the need for multi-level interventions to improve follow-up.