Table 4. Uni- and multivariate logistic regression analysis to predict stone-free status.

Variable	Univariate			Multivariate
	p-value	OR	95% CI	p-value	OR	95% CI
Age	0.499	0.989	0.958-1.021
Sex (male vs. female)	0.970	0.983	0.394-2.454
Body mass index	0.123	1.112	0.972-1.272
Preoperative SWL history	0.888	0.897	0.200-4.035
Preoperative URS history	0.920	1.094	0.189-6.340
Laterality (right vs. left)	0.571	0.776	0.322-1.868
Number of stones	0.104	0.765	0.555-1.056
Maximal diameter of stone	0.785	0.984	0.875-1.106
Total stone volume	0.665	1.000	1.000-1.000
Stone in lower minor calyx
Posterior versus anterior	0.017*	0.258	0.085-0.787	0.002*	0.017	0.001-0.226
Posterior versus both	0.004*	0.155	0.043-0.555	0.003*	0.051	0.007-0.365

OR, odds ratio; CI, confidence interval; SWL, extracorporeal shock wave lithotripsy; URS, ureteroscopic stone surgery.