Table 2 Natural frequency estimates based on the summary sensitivity and specificity and median prevalence of strep A infection from the systematic review of rapid tests for diagnosing group A streptococcus in children with sore throats
From: Understanding test accuracy research: a test consequence graphic
| Â | Disease present | Disease absent | Total |
|---|---|---|---|
Test positive | 300 × 0.857 = 257 | 700 − (700 × 0.954) = 32 | TP + FP = 289 |
Test negative | 300 − (300 × 0.857) = 43 | 700 × 0.954 = 668 | FN + TN = 711 |
|  | 1000 × 0.3 = 300 | 1000 − 300 = 700 | 1000 |