Table 1. The characteristics of the study population.

Characteristic		n	%
Median age at diagnosis (range)		60	(54–65)
Age at diagnosis	≤50	631	14.6
	51–60	1,648	38.1
	>60	2,048	2,048
Sex	Male	2,570	59.4
	Female	1,757	40.6
Self-reported family history of colorectal cancer	No	3,500	80.9
	Yes	827	19.1
Dukes' stage of disease at diagnosis	A	252	5.8
	B	1,171	27.1
	C	1,884	43.5
	D	596	13.8
	Unknown	424	9.8
Tumour site	Colon	2,626	60.7
	Rectosigmoid	416	9.6
	Rectum	1,285	29.7
IMD income category	Most affluent	1,066	24.6
	2	1,016	23.5
	3	979	22.6
	4	739	17.1
	Most deprived	527	12.2
Year of recruitment into NSCCG	2004	789	18.2
	2005	1,489	34.4
	2006	1,073	24.8
	2007	813	18.8
	2008	67	1.6
	2009	50	1.2
	2010	46	1.1
Year of diagnosis of CRC	2003	190	4.4
	2004	1,277	29.5
	2005	1,292	29.9
	2006	1,074	24.8
	2007	366	8.5
	2008	58	1.3
	2009	61	1.4
	2010	9	0.2