Uptake of faecal immunochemical test screening among nonparticipants in a flexible sigmoidoscopy screening programme.

Screening programmes based on single modality testing may prevent individuals with a preference for a different test from participating. We conducted a population-based trial to determine whether nonparticipants in flexible sigmoidoscopy (FS) screening were willing to attend faecal immunochemical test (FIT) screening. In total, 8,407 subjects were invited in a primary FS screening programme. Invitees did not know at the time of FS invitation that nonparticipants would be offered FIT screening. A total of 4,407 nonparticipants of FS screening were invited for FIT screening (cut-off 50 ng haemoglobin/ml). The participation rate to FS screening was 31% [95% confidence interval (CI): 30-32%]. Among the FS nonparticipants 25% (CI: 24-26%) did attended FIT screening. The participation rate of the two-stage recruitment for FS and FIT screening was 45% (CI: 44-46%). FIT screenees were older (p = 0.02), more often women (p < 0.001) and had a lower social economic status (p = 0.01) than FS screenees. The detection rate (DR) for advanced adenoma was 3.5% (CI: 2.5-4.8%), and for colorectal cancer (CRC) it was 0.3% (CI: 0.1-0.8%) among participants to FIT screening. The DR of the two-stage recruitment was 6.1% (n = 202) for an advanced adenoma and 0.5% (n = 16) for a CRC. In conclusion, offering FIT screening to nonparticipants in a FS screening programme increases the overall participation rate considerably, as a quarter of nonparticipants of FS screening was willing to attend FIT screening. The participation rate remains lower for primary FIT screening in the same population (62%). Women in the target population were more likely to refuse FS than FIT screening. Countries introducing FS screening should be aware of these preferences.

Diagnostic yield improves with collection of 2 samples in fecal immunochemical test screening without affecting attendance.

BACKGROUND & AIMS: The fecal immunochemical test (FIT) is superior to the guaiac-based fecal occult blood test in detecting neoplasia. There are not much data on the optimal number of FITs to perform. We conducted a population-based trial to determine attendance and diagnostic yield of 1- and 2-sample FIT screening. METHODS: The study included 2 randomly selected groups of subjects aged 50-74 years (1-sample FIT, n=5007; 2-sample FIT, n=3197). The 2-sample group was instructed to collect fecal samples on 2 consecutive days. Subjects were referred for colonoscopy when at least 1 sample tested positive (≥50 ng hemoglobin/mL). RESULTS: Attendance was 61.5% in the 1-sample group (2979 of 4845; 95% confidence interval, 60.1%-62.9%) and 61.3% in the 2-sample group (1875 of 3061; 95% confidence interval, 59.6%-63.0%; P=.84). In the 1-sample group 8.1% tested positive, and in the 2-sample group 12.8% had at least 1 positive test outcome and 5.0% had 2 positive test outcomes (P<.05). When the mean from both test results in the 2-sample group was used, 10.1% had a positive test outcome (P<.05). The detection rates for advanced neoplasia were 3.1% in the 1-sample group, 4.1% in the 2-sample group with at least 1 positive test outcome, 2.5% when both test results were positive, and 3.7% among subjects with the mean from both test results being positive. CONCLUSIONS: There is no difference in attendance for subjects offered 1- or 2-sample FIT screening. The results allow for the development of efficient FIT screening strategies that can be adapted for local colonoscopy capacities, rather than varying the cut-off value in a 1-sample strategy.