Table V.

Cox regression analyses of variables associated with survival in patients undergoing liver-directed therapy for their colorectal liver metastases

	Univariate			Multivariate
Prognostic factor	Hazard ratio	95% CI	P-value	Hazard ratio	95% CI	P-value
Year of CRLM diagnosis category: 1991–1995	0.97	0.85–1.09	.593	—	—	—
Age at diagnosis of CRLM	1.03	1.02–1.04	<.001	1.03	1.02–1.04	<.001
Male gender	1.06	0.95–1.18	.320	—	—	—
White race	1.03	0.89–1.21	.676	—	—	—
Unmarried	1.18	1.06–1.32	.003	1.06	0.94–1.18	.356
Rural residence	1.08	0.88–1.32	.405	—	—	—
Synchronous disease	1.55	1.39–1.73	<.001	1.67	1.49–1.86	<.001
Rectal primary CRC	0.96	0.85–1.10	.569	—	—	—
Ablation alone	1.15	1.02–1.29	.022	1.18	1.05–1.33	.006
Both pre and postoperative systemic therapy	1.40	1.13–1.72	.002	1.62	1.31–2.01	<.001
Elixhauser index				—	—	—
Comorbidities
None (referent)	—	—	—	—	—	—
1	0.98	0.85–1.13	.780	0.93	0.81–1.10	.288
2–3	1.12	0.98–1.29	.102	1.02	0.89–1.18	.739
>3	1.21	0.99–1.49	.065	1.03	0.83–1.27	.806