Diagnostic accuracy of FIT for CRC and SBD at different cut-offs
| Risk category | FIT positivity | Cut-off (µg/g) | Sensitivity | Specificity | PPV | NPV |
| ≥2 | 37.2 | CRC | 97.0 (94.5 to 98.5) | 64.9 (63.9 to 65.8) | 8.7 (7.8 to 9.7) | 99.8 (99.7 to 99.9) |
| HRA | 65.8 (61.0 to 70.3) | 64.1 (63.1 to 65.0) | 7.6 (6.7 to 8.5) | 97.7 (97.3 to 98.0) | ||
| IBD | 73.1 (68.6 to 77.2) | 64.4 (63.4 to 65.4) | 8.5 (7.7 to 9.5) | 98.1 (97.8 to 98.5) | ||
| SBD | 77.1 (74.6 to 79.5) | 68.2 (67.2 to 69.2) | 24.8 (23.4 to 26.3) | 95.6 (95.1 to 96.1) | ||
| ≥10 | 19.0 | CRC | 90.9 (87.2 to 93.8) | 83.5 (82.8 to 84.3) | 16.1 (14.4 to 17.8) | 99.6 (99.5 to 99.7) |
| HRA | 45.4 (40.5 to 50.3) | 82.2 (81.4 to 83.0) | 10.3 (8.9 to 11.7) | 97.1 (96.7 to 97.5) | ||
| IBD | 57.8 (53.0 to 62.6) | 82.8 (82.0 to 83.6) | 13.3 (11.8 to 14.9) | 97.7 (97.4 to 98.1) | ||
| SBD | 62.6 (59.8 to 65.4) | 87.0 (86.3 to 87.7) | 39.6 (37.4 to 41.8) | 94.5 (93.9 to 95.0) | ||
| ≥150 | 7.6 | CRC | 70.8 (65.6 to 75.7) | 94.6 (94.1 to 95.0) | 31.1 (27.8 to 34.6) | 98.9 (98.7 to 99.1) |
| HRA | 22.1 (18.2 to 26.4) | 93.0 (92.5 to 93.5) | 12.4 (10.1 to 15.0) | 96.4 (96.0 to 96.8) | ||
| IBD | 36.8 (32.2 to 41.5) | 93.7 (93.2 to 94.2) | 21.0 (18.1 to 24.1) | 97.0 (96.7 to 97.4) | ||
| SBD | 41.0 (38.2 to 43.9) | 96.9 (96.5 to 97.3) | 64.5 (60.9 to 67.9) | 92.4 (91.8 to 92.9) |
95% CIs within brackets.
CRC, colorectal cancer; FIT, faecal immunochemical test; HRA, high-risk adenoma; IBD, inflammatory bowel disease; NPV, negative predictive value; PPV, positive predictive value; SBD, serious bowel disease.