2×2 contingency table summarising the performance of the IRB PSCA tool
| Index test | Reference standard | Total | |
|---|---|---|---|
| Concussion confirmed | No concussion | ||
| PSCA test positive | 55 (TP) | 26 (FP) | 81 |
| PSCA test negative | 10 (FN) | 74 (TN) | 84 |
| Total | 65 | 100 | 165 |
FN, false negative; FP, false positive; IRB, International Rugby Board; PSCA, Pitch Side Concussion Assessment; TN, true negative; TP, true positive.