The aim of this study was to estimate the cumulative risk of a false-positive (FP) result in a fecal occult blood test (FOBT) through 7 screening rounds and to identify its associated factors in a population-based colorectal cancer screening program.
During the period of 2000 to 2017, the cumulative FP risk was 16.3% (IC95%: 14.6%–18.3%), adjusted by age, sex, and type of test. The median number of screens was 2. Participants who began screening at age 50 years had a 7.3% [95% confidence interval (CI), 6.35–8.51] and a 12.4% (95% CI, 11.00–13.94) probability of an FP with 4 screening rounds of guaiac-based test and immunochemical test, respectively. Age, the fecal immunochemical test, first screening,
and number of personal screens were factors associated with an FP result among screenees.
The cumulative risk of an FP in colorectal screening using FOBT seems acceptable as the colonoscopy, with its high accuracy, lengthens the time until additional colorectal screening is required, while complication rates remain low.