Uptake, positivity rate and diagnostic yield of the faecal immunochemical test (FIT) at years 1, 2 and 3 and over all 3 years
| Uptake | Positivity rate | Colonic exam performed | Diagnostic yield* | ||||||||||
| Invited | Completed FIT test† | Tested positive‡ | Any exam§ | Colonoscopy¶ | Colorectal cancer | Advanced adenomas** | |||||||
| Year | n | n | (%) | n | (%) | n | (%) | n | (%) | n | (%) | n | (%) |
| 1 | 8009 | 5938 | (74.1) | 346†† | (5.8) | 320 | (92.5) | 317 | (99.1) | 8 | (2.5) | 78 | (24.4) |
| 2 | 5479 | 5329 | (97.3) | 236 | (4.4) | 216 | (91.5) | 212 | (98.1) | 7 | (3.2) | 37 | (17.1) |
| 3 | 5179 | 5022 | (97.0) | 204 | (4.1) | 189 | (92.6) | 184 | (97.4) | 2 | (1.1) | 36 | (19.0) |
| Cumulative | 8009 | 5938 | (74.1) | 786‡‡ | (13.2) | 725 | (92.2) | 713 | (98.3) | 17 | (2.3) | 151 | (20.8) |
| Routine year 3 colonic exam | 4500 | 4420 | (98.2) | 12 | (0.3) | 295 | (6.6) | ||||||
| Entire study findings | 5225 | 5133 | (98.2) | 29 | (0.6) | 446 | (8.5) | ||||||
*Diagnostic yield in participants who underwent colonic examination.
†Participants who gave consent, returned an analysable FIT at year 1 and did not subsequently withdraw from the study.
‡Percentages calculated using the number of participants who completed FIT as the denominator. In the pilot study, a threshold of 20 µg haemoglobin (Hb)/g faeces was used to denote test positivity. The positivity threshold used in the rest of the study was 40 µg Hb/g faeces.
§Participants who underwent colonoscopy or CT colonography. Percentages calculated using the number of FIT positive participants as the denominator.
¶Participants who had a colonoscopy. Percentages calculated using the number of participants who underwent colonic examination as the denominator.
**Advanced adenomas were defined as adenomas ≥10 mm, with villous or tubulovillous histology, or high-grade dysplasia.
††Three participants tested positive at year 1 during the pilot study based on a threshold of 20 µg Hb/g. They are included as FIT positive in this table even though their faecal haemoglobin levels were lower than the 40 µg Hb/g threshold used in the rest of the study.
‡‡Participants who were FIT positive with any FIT, regardless of whether they had completed all FITs that they were offered.