Performance of the CATCH rule: A) Using the 4 high-risk signs, sensitivity was 100.0% (95% CI 86.2% to 100.0%) and specificity was 70.2% (95% CI 68.6% to 71.6%); 30.2% of patients would undergo CT scanning. B) Using the 4 high-risk and 3 medium-risk signs, sensitivity was 98.1% (95% CI 94.6% to 99.4%) and specificity was 50.1% (95% CI 48.5% to 51.7%); 51.9% of patients would undergo CT scanning.
| A) RESULT | NEEDED NEUROLOGIC INTERVENTION | DID NOT NEED NEUROLOGIC INTERVENTION |
| Positive (≥ 1 high-risk factor) | 24 | 1144 |
| Negative (no high-risk factors) | 0 | 2698 |
| B) RESULT | NEEDED NEUROLOGIC INTERVENTION | DID NOT NEED NEUROLOGIC INTERVENTION |
| Positive (≥ 1 high-risk factor) | 156 | 1851 |
| Negative (no high-risk factors) | 3 | 1856 |
CATCH—Canadian Assessment of Tomography for Childhood Head Injury, CT—computed tomography.
Data from Osmond et al.38