Impact of Gram stain results on initial treatment selection in patients with ventilator-associated pneumonia: a retrospective analysis of two treatment algorithms

Table 3 Results of Gram stain compared with Staphylococcus aureus culture

	Staphylococcus aureus growth in culture^a
GPC clusters on Gram stain	Yes	No	Total
Yes	50	14	64
No	9	58	67
Total	59	72

^a Sensitivity of Gram stain: 50/59 = 84.7%; specificity of Gram stain: 58/72 = 80.6%; negative predictive value: 58/67 = 86.6%; positive predictive value: 50/64 = 78.1%
GPC Gram-positive cocci

ISSN: 1364-8535