Positive likelihood ratios (LR+ve) at optimum cut off points
| Test | LR+ve | 95% CI |
| FLDH + TPR | 18 | 5.4 to 65 |
| FLDH | 7.3 | 3.5 to 17 |
| TPR | 5.9 | 3 to 12.6 |
| LDHR | 2.4 | 1. 7 to 3.6 |
FLDH = pleural fluid absolute lactic dehydrogenase; TPR = pleural fluid to serum ratio of total protein; LDHR = pleural fluid to serum ratio of LDH.