Likelihood ratios and post-test probability for an abnormal CT scan for each symptom variable
| Symptom variable | Likelihood ratio | Post-test probability |
|---|---|---|
| The common (average) pre-test probability was calculated to be 0.075. | ||
| Dizziness | 0.643 | 0.046 |
| Blurred vision | 0.85 | 0.06 |
| Nausea | 1.98 | 0.13 |
| Vomiting | 4.17 | 0.24 |
| Headache | 1.009 | 0.07 |
| Severe headache | 2.98 | 0.18 |