Diagnostic performance of a low COVID-19 risk threshold (less than four points on the diagnostic score) and high-risk threshold (greater than nine points)
| Prevalence | ||||||
| Low-risk diagnostic score threshold (<4) | Study population | 0.5 | 0.2 | 0.1 | 0.05 | 0.01 |
| Sensitivity | 26.6% | – | – | – | – | – |
| Specificity | 96.6% | – | – | – | – | – |
| PPV | 89.0% | 88.7% | 66.2% | 46.6% | 29.2% | 7.3% |
| NPV | 56.0% | 56.8% | 84.0% | 92.2% | 96.2% | 99.2% |
| High-risk diagnostic score threshold (>9) | ||||||
| Sensitivity | 37.0% | – | – | – | – | – |
| Specificity | 96.1% | – | – | – | – | – |
| PPV | 90.1% | 90.4% | 70.1% | 51.0% | 33.0% | 8.6% |
| NPV | 61.2% | 60.4% | 85.9% | 93.2% | 96.7% | 99.3% |
Low-risk threshold diagnostic accuracy is for identifying patients without COVID-19, whereas high-risk threshold is for identifying patients with COVID-19.
NPV, negative predictive value; PPV, positive predictive value.