Table 4. Multivariate regression analysis of predictive factors for PTBD duration.

	Coeff(B)	Std Coeff(β)	95% CI of B		P value
			Lower	Upper
Previous EST	-2.08	-0.14	-4.22	0.07	0.057
Short diameter of largest stone	0.16	0.17	0.02	0.30	0.025
Total bilirubin	0.50	0.24	0.20	0.81	<0.001

Linear regression analysis using backward stepwise elimination.

Coeff = coefficient; Std Coeff = standard coefficient; CI = confidence interval.

coefficient of determination (R2) = 0.114; P < 0.001.

EST = endoscopic sphincterotomy.