Table 4.

Multivariable logistic regression analysis of factor affecting residual fragments

	OR	95% CI	P
Age	0.96	0.94–0.98	<0.001
Stone size	1.01	0.94–1.07	0.873
Stone location
Upper pole	0.96	0.39–2.80	0.940
Interpolar	1.08	0.38–3.40	0.893
Lower pole	5.63	2.21–16.4	0.001
Pelvis	4.67	1.72–14.7	0.004
Proximal ureter	0.51	0.18–1.59	0.218
Pre-stenting	0.32	0.17–0.60	<0.001
Scope used for >2 cases before (reference ≤2)	0.73	0.35–1.52	0.390
Faulty scope changed during the case	12.8	3.21–69.4	0.001
Total operation time	1.05	1.03–1.08	<0.001

CI=Confidence interval, OR=Odds ratio