Table 3.

Multivariable logistic regression analysis of factors that are related to postoperative urinary retention

Variable	ORunadj	ORadj	95% CI	P value
Total hip arthroplasty	1.6	1.4	1.1 to 1.9	0.02
Age (yr)	0.99	1.0	1.0 to 1.0	0.85
Dose of intrathecal long-acting local anesthetic	1.5	1.2	0.94 to 1.4	0.17
Type of anesthetic by gender
Male
General anesthesia only	1.0	1.0	-
Spinal anesthesia without intrathecal morphine	1.5	1.6	0.71 to 3.6	0.26
≤100 μg intrathecal morphine	6.5	7.1	3.6 to 14.0	<0.001
101–150 μg	8.6	9.3	4.2 to 20.1	<0.001
>150 μg	11.6	12.2	4.3 to 34.5	<0.001
Female
General anesthesia only	1.0	1.0	-
Spinal anesthesia without intrathecal morphine	1.3	1.3	0.59 to 2.9	0.51
≤100 μg intrathecal morphine	1.7	1.7	0.84 to 3.3	0.14
101–150 μg	2.8	2.6	1.2 to 5.8	0.02
>150 μg	1.5	1.4	0.53 to 3.6	0.51

CI = confidence interval; OR_adj = adjusted odds ratio; OR_unadj = unadjusted odds ratio