Baseline characteristics (first screening round)
| Repeat 1-sample FIT screening | Once-only 2-sample FIT screening | ||||
| Group I | Group II | Group III | Reference group 0 | p Value | |
| Invited subjects, n | 2493 | 2503 | 2505 | 3197 | |
| Median age, years (IQR) | 60.0 (55.0–66.0) | 60.0 (55.0–66.0) | 60.0 (55.0–65.5) | 62.0 (56.0–68.0) | 0.001 |
| Male sex, n (%) | 1223 (49.1) | 1254 (50.1) | 1254 (50.1) | 1593 (49.8) | 0.87 |
| SES, n (%) | 0.99 | ||||
| High | 993 (39.8) | 1019 (40.7) | 1019 (40.7) | 1280 (40.0) | |
| Intermediate | 509 (20.4) | 503 (20.1) | 503 (20.1) | 640 (20.0) | |
| Low | 991 (39.8) | 981 (39.2) | 983 (39.2) | 1277 (39.9) | |
Groups I, II and III: Individuals were invited for two 1-sample FIT screening rounds after an interval of 1, 2 or 3 years, respectively. Reference group 0: Individuals were invited for one 2-sample FIT screening round.
Socio-economic status (SES) was based on the data of Statistics Netherlands (http://www.cbs.nl), providing average SES per postal code area, each representing small neighbourhoods.
IQR, interquartile range; FIT, faecal immunochemical test (OC-Sensor Micro).