Table 2. Cox proportional hazards model of the risk of death in relation to the (a) number of first-degree family members affected by colorectal cancer and (b) any family history of colorectal cancer.

(a)
	Univariate			Multivariate
Characteristic	Hazard ratio	95% CI	P-value	Hazard ratio	95% CI	P-value
Number of family members affected
0	1.00			1.00
1	0.89	0.81–0.99	0.03	0.91	0.82–1.01	0.06
⩾2	0.71	0.54–0.93	0.01	0.75	0.57–0.98	0.04
Age at diagnosis (per year increase)	1.01	1.00–1.01	<0.01	1.01	1.00–1.01	<0.01
Sex
Male	1.00			1.00
Female	0.80	0.74–0.86	<0.01	0.84	0.78–0.90	<0.01
Dukes' stage of disease at diagnosis
A	1.00			1.00
B	1.45	1.18–1.79	<0.01	1.47	1.19–1.81	<0.01
C	2.79	2.29–3.40	<0.01	2.85	2.34–3.48	<0.01
D	11.70	9.55–14.3	<0.01	11.95	9.76–14.65	<0.01
Unknown	3.41	2.76–4.21	<0.01	3.40	2.75–4.21	<0.01
Site of tumour
Right colon	1.00			1.00
Left colon	0.96	0.88–1.05	0.33	0.84	0.77–0.92	<0.01
Colon NOS	1.25	1.08–1.44	<0.01	1.06	0.92–1.22	0.44
Rectum	1.07	0.98–1.17	0.154	0.97	0.89–1.07	0.54
Year	1.03	1.02–1.05	<0.01	0.99	0.98–1.01	0.67
(b)
Number of family members affected
0	1.00			1.00
⩾1	0.87	0.79–0.95	<0.01	0.89	0.81–0.98	0.02
Age at diagnosis (per year increase)	1.01	1.00–1.01	<0.01	1.01	1.00–1.01	<0.01
Sex
Male	1.00			1.00
Female	0.80	0.74–0.86	<0.01	0.84	0.78–0.90	<0.01
Dukes' stage at diagnosis
A	1.00			1.00
B	1.45	1.18–1.79	<0.01	1.47	1.19–1.81	<0.01
C	2.79	2.29–3.40	<0.01	2.85	2.34–3.48	<0.01
D	11.70	9.55–14.3	<0.01	11.95	9.75–14.64	<0.01
Unknown	3.41	2.76–4.21	<0.01	3.40	2.75–4.21	<0.01
Tumour site
Right colon	1.00			1.00
Left colon	0.96	0.88–1.05	0.33	0.84	0.77–0.92	<0.01
Colon NOS	1.25	1.08–1.44	<0.01	1.06	0.92–1.22	0.43
Rectum	1.07	0.98–1.17	0.154	0.97	0.89–1.07	0.54
Year of diagnosis	1.03	1.02–1.05	<0.01	1.00	0.98–1.01	0.67

Abbreviations: CI=confidence interval; HR=hazard ratio; NOS=not otherwise specified.