Sensitivity (%) | Specificity (%) | PPV (%) | NPV (%) | +LR | –LR | |
Qualitative ETA cultures | 90 | 14 | 21 | 85 | 1 | 0.6 |
Quantitative ETA cultures | 72 | 55 | 30 | 88 | 1.6 | 0.5 |
Qualitative ETA is growth of any organism; quantitative ETA is growth of any organism at >106 colony-forming units (CFU)/ml.20 A likelihood ratio is a likelihood that a person with a positive (or negative) test has the disease in question; further detail can be found in Strauss et al.25
BAL, bronchoalveolar lavage; ETA, endotracheal aspirate; NPV, negative predictive value; PPV, positive predictive value; +LR, positive likelihood ratio; –LR, negative likelihood ratio; VAP, ventilator-associated pneumonia.