Table 3. Multivariable Cox proportional hazards model.

Variables are listed with their respective hazard ratios. Prostate volume did not (by neither digital rectal exam nor transrectal ultrasound estimate) maintain significance in our multivariable model.

Variable	Hazard Ratio	95% Wald CL
Age (per 10 years)	1.33	1.15, 1.53
Serum PSA (per 5 ng/mL)	1.44	1.14, 1.82
AUA symptom score (per 5 points)	0.76	0.68, 0.85
BPH Impact Index (per 1 point)	1.12	1.07, 1.17
Maximal urinary flow rate (per 5 mL/second)	0.74	0.60, 0.90
Post-voiding residual volume (per 100 mL)	1.17	1.04, 1.30

N=3036 with non-missing data for all predictors. c-statistic = 0.635