Table 1.

Multivariable predictors of metastasis among CRPC patients

Variables	Univariable analysis			Multivariable analysis
	HR	95% CI	P	HR	95% CI	P*
Ethnic group
White	ref	-	-	ref	-	-
Other	1.04	0.80–1.36	0.742	0.90	0.67–1.21	0.490
Biopsy Gleason score
2 – 6	ref	-	-	ref	-	-
7	1.43	0.95–2.15	0.085	1.36	0.90–2.07	0.148
8 – 10	1.69	1.13–2.54	0.011	1.61	1.06–2.43	0.026
Unknown	1.26	0.85–1.86	0.249	1.22	0.81–1.82	0.340
Primary localized treatment
None	ref	-	-	ref	-	-
RP and/or XRT	1.31	1.02–1.69	0.040	1.38	1.04–1.82	0.028
Year of CRPC diagnosis (years)	0.99	0.95–1.02	0.456	0.99	0.95–1.04	0.774
Age at CRPC (years)	0.98	0.97–0.996	0.010	0.99	0.98–1.00	0.170
PSA at CRPC (log[ng/mL])	1.57	1.40–1.76	<0.001	1.64	1.44–1.87	<0.001
PSADT at CRPC (months)
>6	ref	-	-	ref	-	-
≤6	1.61	1.20–2.17	0.002	1.42	1.02–1.98	0.040
Missing	1.60	1.18–2.17	0.003	1.06	0.73–1.54	0.753
Time from ADT to CRPC (years)	0.96	0.92–0.996	0.030	1.01	0.97–1.05	0.727

^*Adjusted for Veteran Affairs Medical Center

ADT: androgen deprivation therapy; CI: confidence interval; CRPC: castration-resistant prostate cancer; HR: hazard ratio; RP: radical prostatectomy.