TABLE 2.

Gram stain agreement analysis^a

ETA Gram stain	No. of BALF samples with Gram stainb:		Total	PPV/NPV (%)c
	+	−
ETA Gram+	66	41	106	PPV, 62
ETA Gram−	70	108	178	NPV, 61
Total	135	149	284

^aGram stain of endotracheal aspirates (ETA) compared to that of bronchoalveolar lavage fluid (BALF) in patients with suspected ventilator-associated pneumonia.

^bSensitivity is 49% and specificity is 73%. The Cohen's kappa coefficient is 0.22.

^cPPV, positive predictive value; NPV, negative predictive value.