Table 3.

Summary of the results of the multivariate models of ESBL-E VAP (all variables significant in the univariate analysis (see Tables 1, 2) were included in the selection process at the first step of the stepwise selection, i.e., urinary bladder before ICU admission, albumin level, ARDS in the 7 days before VAP; ESBL E. coli only, SOFA score at the time of VAP)

Parameter	Odds ratio	CI 95% min	CI 95% max	Pr > chi-sq
Model 1 including rectal semi-quantitative result (AUC 0.769)
Rectal colonization (semi-quantitative) density				0.0076*
None/very rare/rare	1
Some	3.103	0.457	21.072	0.2467
Numerous	11.594	2.343	57.379	0.0027
Very numerous	11.166	1.715	72.698	0.0116
ESBL E. coli only	0.291	0.122	0.695	0.0055
Model 2 including throat qualitative result (AUC 0.838)
Throat colonization with ESBL-E (qualitative)	17.321	6.452	46.503	< 0.0001
Urinary bladder at admission	2.727	0.954	7.799	0.0613
Model 3 including both throat and rectal semi-quantitative results (AUC: 0.872)
Throat colonization with ESBL-E (qualitative)	21.161	6.91	64.802	< 0.0001
Rectal colonization (semi-quantitative) density				0.0117*
None/very rare/rare	1
Some	2.61	0.3	22.705	0.3846
Numerous	15.732	2.469	100.225	0.0035
Very numerous	7.701	0.908	65.308	0.0613

ESBL-E extended spectrum beta-lactamase producing Enterobacterales, VAP ventilator-associated pneumonia

*The p value referred to the global impact of the semi-quantitative value. OR: italicized referred to comparison of one particular density to the reference