Colonoscopy — Colorectal Cancer
Test Characteristics
| Metric | Value |
|---|---|
| False-negative rate | 1.5% (sensitivity 98.5%) |
| False-positive rate | ~0% (specificity 99.9%) |
| Bayes factor | 100× |
| Base rate | 0.5% for CRC in average-risk adults aged 45–75 |
Interpreting Results
Essentially a definitive diagnostic procedure — positive findings go directly to histological confirmation.
- + result: goes directly to tissue diagnosis — essentially certain
- − result: base rate is at identical twin level (0.5%)
Sources:
- Head-to-head diagnostic meta-analysis, PMC, 2023.