Area under the curve (AUC) for the various test criteria (Wilcoxon estimate)
| Criteria | AUC | 95% CI |
| FLDH | 0.89 | 0.86 to 0.96 |
| TPR | 0.86 | 0.80 to 0.91 |
| LDHR | 0.82 | 0.77 to 0.89 |
| FLDH + TPR | 0.90 | 0.86 to 0.95 |
FLDH = pleural fluid absolute lactic dehydrogenase; TPR = pleural fluid to serum ratio of total protein; LDHR = pleural fluid to serum ratio of LDH.