Table 1.
Sample size and positive predictive value lower bound based on ovarian cancer as the rarest cancer considered in a validation-only prediagnostic performance study with 1-year follow-up
| Standard sample size trade-off targets |
|||
|---|---|---|---|
| Targeted quantity | Scenario 0 | Scenario 1 | Scenario 2 |
| TPRTAR | 0.80 | 0.50 | 0.80 |
| TPRLOW | 0.70 | 0.20 | 0.50 |
| FPRTAR | 0.01 | 0.0000 | 0.0000 |
| FPRUPP | 0.03 | 0.0005 | 0.0005 |
| PPVLOW(j) for ovarian cancer | 0.003 | 0.05 | 0.11 |
| No. of cases | 70 | 12 | 12 |
| No. of test-positive cases | 59 | 7 | 10 |
| No. of controls | 300 | 7500 | 7500 |
| No. of test-positive controls | 3 | 0 | 0 |
| Sample size | 720 000 | 163 000 | 163 000 |
FPR = false-positive rate; PPV = positive predictive value; TPR = true-positive rate.