Timely colonoscopy follow-up and risk factors for incomplete two-step colorectal cancer screening

Context: Prior studies have shown patients with abnormal stool-based testing for colorectal cancer (CRC) screening should undergo follow-up colonoscopy as soon as possible, ideally within 90 days and no later than 180 days from the date of positive screening. Low income, minority, and uninsured or underinsured patients have the lowest rates of CRC screening.

Objective: To determine the timeliness of colonoscopy completion following abnormal stool-based screening for CRC within a single academic health system over a two-year period and to identify patient factors associated with incomplete screening. Timely colonoscopy was defined as within nine months of abnormal stool-based test.

Study Design and Analysis: Retrospective Cohort Study. Descriptive statistics and survival analysis were used to compare time to follow-up colonoscopy between FIT and stool DNA tests.

Setting or Dataset: A single academic health center clinical data repository.

Population Studied: Patients 50 to 75 years of age living in an urban setting who had positive FIT or stool DNA (COLOGUARD) test result between October 1, 2020, and February 28, 2022.

Intervention/Instrument: Follow-up colonoscopy data were obtained for the study period of October 1, 2020, and November 30, 2022, to allow for a nine-month follow-up period.

Outcome Measures: Demographic variables and time between positive screening test and follow-up colonoscopy in days.

Results: There were a total of 1,339 patients with positive stool-based tests during the study timeframe, including 682 FIT (668 patients) and 671 stool DNA tests (671 patients). The mean age at initial abnormal test result was 62.5 years (range 50-74, StDev 6.9), and 647 patients (48.3%) were male. The majority (84.3%) identified as white and not of Hispanic or Latino ethnicity (71.0%). 536 patients (40.0%) had timely follow-up for abnormal stool-based CRC screening. There were no statistically significant differences in the proportion of patients with timely follow-up based on sex, race, ethnicity, insurance type, Medicare status, or test type. The survival distributions for the two types of stool-based tests were not statistically different, p=0.17.

Conclusions: Although patients with abnormal stool-based screening for CRC should have follow-up colonoscopy as soon as possible and within a maximum of nine months, approximately 60% of patients do not. No specific patient or test type factors were associated with incomplete screening in this study.