Table 4.

Parameters affecting complication rate on univariate analysis.

	Patients with complication	Patients without complication	p	OR, 95% CI
No. with preoperative nephrostomy tube	20	22	0.002**	3.3 (1.6–6.5)
Stone burden, mm	14.3 ± 4.7	12.1 ± 5.4	0.004*
Single/multiple	47/13	152/18	0.031**	2.3 (1.1–5.1)
Single stone location
Distal/proximal	26/21	109/43	0.036**	2.1 (1.0–4.0)
Operation time, min	39.4 ± 12.3	25.9 ± 10.3	0.001*

Data are presented as mean ± SD, unless otherwise indicated.

CI = confidence interval; OR = odds ratio; SD = standard deviation.

*t test.

**Chi‐square test.