TABLE 3.

Stepwise multivariable logistic regression analysis for bacterial predictors of individual source groups among 329 Escherichia coli isolates from women with cystitis or pyelonephritis and uninfected women

Outcome variable (referent)	Predictor variablea	P value	Odds ratio	95% CIb
Cystitis (fecal)	K1 kpsM variant	0.001	0.30	0.15-0.63
	ibeA	0.004	4.54	1.62-12.73
Pyelonephritis (fecal)	K1 kpsM variant	<0.001	0.06	0.018-0.20
	F8 papA allele	0.008	0.07	0.009-0.050
	papG allele III	0.001	0.095	0.02-0.38
	iha	<0.001	5.96	2.47-14.40
	ibeA	<0.001	23.66	5.21-107.39
	papEF	<0.001	29.72	7.74-114.04
Pyelonephritis (cystitis) Ia	F16 papA allele	0.004	0.23	0.008-0.63
	Group B1	0.013	0.35	0.16-0.81
	papG allele II	<0.001	8.44	3.93-18.12
	O75	0.002	11.22	2.35-53.59
Pyelonephritis (cystitis) IIa	papG allele II	<0.001	5.20	2.78-9.82
	afa/draBC	0.007	3.68	1.44-9.43
	malX	0.003	2.48	1.36-4.53

^aPredictor variables shown are those from the last step in which all variables included in the model yielded a P value of ≤0.015. Two different sets of candidate predictor variables were used for each endpoint (I, full set; II, short set). The first (full) set included all bacterial characteristics analyzed, i.e., the four phylogenetic groups, the UTI-associated O antigens (individually and collectively), the O11/O17/O73/O77 antigens, the individual papA alleles, individual virulence factors, and ExPEC status. The second (short) set included only the papA alleles, individual virulence factors, and ExPEC status. Results for “Cystitis (fecal)” and “Pyelonephritis (fecal)” were the same with either set of candidate predictor variables. For “Pyelonephritis (cystitis),” the two sets of candidate predictor variables yielded different results, as shown.

^bCI, confidence interval.