Table 3.

—Cox Proportional Hazards Model Results for Antibiotics and Mortality

	Macrolide (n = 47)			Fluoroquinolone (n = 90)			Cephalosporin (n = 93)
Model	HR	95% CI	P Value	HR	95% CI	P Value	HR	95% CI	P Value
Unadjusted (n = 235)	0.63	0.33-1.19	.15	1.18	0.75-1.85	.48	0.86	0.54-1.36	.51
Multivariable adjusted (n = 235)	0.46	0.23-0.92	.028a	0.97	0.61-1.55	.90b	0.76	0.47-1.25	.28c
Propensity adjustedd (n = 193)	0.37	0.16-0.88	.024	0.84	0.45-1.57	.58	0.93	0.53-1.63	.80

See Table 1 legend for expansion of abbreviations.

^aAdjusted for age, SAPS II, and covariates imbalanced with P < .1: duration of ICU stay prior to study enrollment, tidal volume randomization group, presence of pneumonia, and presence of sepsis.

^bAdjusted for age, SAPS II, and covariates imbalanced with P < .1: sex, duration of intubation prior to study enrollment, and presence of pneumonia.

^cAdjusted for age, SAPS II, and covariates imbalanced with P < .1: duration of hospitalization prior to study enrollment, and presence of trauma.

^dC statistics for propensity score regression models were as follows: macrolide 0.87, fluoroquinolone 0.80, cephalosporin 0.67.