Table 4.

Results of logistic regression

Variable	β coefficient	Standard error	Wald χ2	p value	Odds ratio	95% CI
Age
> 65 years versus 0–65 years	0.070	0.528	0.018	0.894	1.073	0.381–3.018
Sex
Female versus male	−0.475	0.250	3.606	0.058	0.387	0.145–1.031
Organism
Susceptible Staphylococcus versus other	0.138	0.581	0.056	0.813	1.148	0.367–3.586
Resistant Staphylococcus versus other	0.482	0.674	0.511	0.475	1.619	0.432–6.071
Charlson Comorbidity Index
1–3 versus 0	0.495	0.574	0.743	0.389	1.640	0.533–5.050
> 4 versus 0	0.350	0.628	0.311	0.577	1.420	0.414–4.862
Timing
≤ 30 days versus 31–90 days	−0.517	0.274	3.565	0.059	0.356	0.122–1.040
Joint
Hip versus knee	0.032	0.245	0.017	0.896	1.066	0.409–2.779