TABLE 5.

Time to result for most common etiologic agents of HAP/VAP according to the teaching status of the hospital^a

Etiologic agent	Time to first ID			Time to first AST
	Median time (h)		P	Median time (h)		P
	Teaching	Nonteaching		Teaching	Nonteaching
Gram positive, monomicrobial
Staphylococcus aureus	26.5 (18.8–46.0)	31.9 (21.4–49.1)	<0.0001	54.8 (45.6–69.2)	62.0 (46.7–72.3)	<0.0001
Streptococcus pneumoniae	36.8 (22.2–60.0)	47.3 (29.7–68.5)	<0.0001	72.5 (64.4–86.6)	75.2 (67.2–93.2)	0.0006
Gram negative, monomicrobial
Acinetobacter spp.	36.0 (18.9–52.0)	49.0 (28.7–69.0)	0.0001	57.4 (46.2–70.2)	69.1 (56.7–86.1)	0.0001
Escherichia coli	36.6 (20.5–47.2)	42.0 (23.4–50.2)	0.0003	47.6 (43.3–59.8)	48.5 (43.1–62.9)	0.24
Enterobacter spp.	38.8 (19.1–48.6)	41.2 (23.6–50.1)	0.030	49.4 (43.3–65.0)	48.9 (42.9–64.4)	0.88
Haemophilus spp.	33.0 (20.2–49.9)	41.1 (25.1–54.2)	<0.0001	55.5 (45.6–71.1)	61.2 (47.4–76.6)	0.0072
Klebsiella spp.	35.8 (19.7–46.8)	41.3 (23.6–50.1)	0.0001	47.9 (43.1–61.1)	49.3 (43.4–64.4)	0.19
Pseudomonas aeruginosa	34.1 (21.3–49.9)	41.2 (23.2–57.8)	<0.0001	57.1 (46.6–70.9)	63.5 (48.5–74.5)	<0.0001
Serratia marcescens	42.4 (25.0–56.1)	42.5 (24.3–49.1)	0.54	51.6 (45.2–65.9)	47.6 (42.5–50.6)	0.0007
Stenotrophomonas maltophilia	40.9 (21.2–63.1)	44.6 (22.9–66.7)	0.08	65.1 (49.8–73.6)	68.3 (53.0–87.1)	0.0011
Polymicrobial
Mixed Gram positive (n = 611)	32.1 (22.6–49.1)	43.0 (25.3–59.2)	0.0002	64.0 (48.3–74.5)	70.4 (60.8–82.1)	<0.0001
Mixed Gram negative (n = 1,627)	40.3 (21.9–63.2)	46.1 (25.7–67.2)	<0.0001	62.4 (47.6–72.3)	67.4 (52.8–77.7)	<0.0001
Mixed Gram positive and negative (n = 3,589)	31.3 (21.2–51.1)	38.7 (22.2–54.5)	0.0010	62.0 (47.3–72.5)	65.2 (49.7–76.3)	<0.0001

^aIQR values are indicated in parentheses.