Table 3.
Test results for three-sample FITs (all FIT brands) requested in primary care in symptomatic patients, stratified by age and related to CRC diagnoses
| Test result | Aged ≥18 years, n= 15 789 | Aged ≥40 years, n= 13 129 | Aged ≥50 years, n= 11 375 | Aged ≥60 years, n= 9266 | Aged ≥70 years, n= 6034 | Aged ≥80 years, n= 2328 |
|---|---|---|---|---|---|---|
| Colorectal cancer, n | 304 | 301 | 290 | 263 | 196 | 78 |
| True positive, n | 277 | 275 | 265 | 240 | 176 | 70 |
| False negative, n | 27 | 26 | 25 | 23 | 20 | 8 |
| False positive, n | 4298 | 3746 | 3394 | 2898 | 2018 | 862 |
| True negative, n | 11 187 | 9082 | 7691 | 6105 | 3820 | 1388 |
| Sensitivity, % | 91.1 | 91.4 | 91.4 | 91.3 | 89.8 | 89.7 |
| Specificity, % | 72.2 | 70.8 | 69.4 | 67.8 | 65.4 | 61.7 |
| PPV (95% CI) | 6.1 (5.4 to 6.7) | 6.8 (6.1 to 7.6) | 7.2 (6.4 to 8.1) | 7.6 (6.7 to 8.6) | 8.0 (6.9 to 9.2) | 7.5 (5.8 to 9.2) |
| NPV (95% CI) | 99.8 (99.7 to 99.8) | 99.7 (99.6 to 99.8) | 99.7 (99.5 to 99.8) | 99.6 (99.5 to 99.8) | 99.5 (99.3 to 99.7) | 99.4 (99.0 to 99.8) |
| LR+ | 3.28 | 3.13 | 2.99 | 2.84 | 2.60 | 2.34 |
| LR– | 0.12 | 0.12 | 0.12 | 0.13 | 0.16 | 0.17 |
CI = confidence interval. CRC = colorectal cancer. FIT = faecal immunochemical test. LR− = negative likelihood ratio. LR+ = positive likelihood ratio. NPV = negative predictive value.
PPV = positive predictive value.