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 >10

^{6}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*.25BAL, 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.