TABLE 3.

Cox regression analysis of risk factors for MDR P. aeruginosa intestinal colonization in ICU patients: impact of exposure to antibiotic therapy

Characteristic	Results for crude analysis:		Results for adjusted analysis:
	cHRa (95% CI)	P	aHR (95% CI)	P
Age > 65 yr	1.11 (0.72–1.73)	0.63	1.38 (0.86–2.19)	0.17
Male gender	1.20 (0.94–1.52)	0.13	1.20 (0.94–1.54)	0.14
SAPS score at ICU admission (>40)	1.53 (0.79–2.37)	0.054	1.26 (0.79–2.02)	0.32
Charlson index of ≥3	1.96 (1.26–3.04)	0.003	1.97 (1.22–3.18)	0.006
Prior hospital stay	1.15 (0.75–1.78)	0.52
Prior fluoroquinolonesb	1.02 (1.00–1.04)	0.013	1.02 (1.00–1.04)	0.039
Prior aminoglycosidesb	1.02 (0.94–1.12)	0.59
Prior carbapenemsb	1.04 (1.01–1.07)	0.007	1.03 (1.00–1.07)	0.041
Prior ertapenemb	1.08 (1.03–1.14)	0.002	1.08 (1.02–1.14)	0.004
Prior colistinb	1.03 (0.99–1.07)	0.11	1.03 (0.99–1.08)	0.12
Prior antipseudomonal cephalosporinsb	1.01 (0.98–1.05)	0.37
Prior other cephalosporinsb	1.00 (0.98–1.03)	0.58
Prior piperacillin-tazobactamb	0.98 (0.94–1.00)	0.13	0.98 (0.95–1.01)	0.29
Prior penicillinb	1.00 (0.99–1.02)	0.65
Prior glycopeptidesb	0.99 (0.97–1.01)	0.53

^acHR, crude hazard ratio.

^bAntibiotics per day.