Table 3. Descriptive statistics of study population by the participation in screening at index invitation.

	Cases		Controls
	All, n	Participation in screening, n (%)	All, n	Participation in screening, n (%)
All	1907	1451 (76)	18 978	16 347 (86)
Age at death (years)
50–54	123	95 (77)	1246	1140 (91)
55–59	371	286 (77)	3698	3352 (91)
60–64	433	334 (77)	4310	3878 (90)
65–69	416	325 (78)	4115	3573 (87)
70–74	302	230 (76)	3006	2473 (82)
75–84	182	127 (70)	1810	1366 (75)
Period of death
1992–1996	117	90 (77)	1160	1021 (88)
1997–2001	361	268 (74)	3581	3111 (87)
2002–2006	585	452 (77)	5833	5018 (86)
2007–2011	844	641 (76)	8404	7197 (86)
Age at index invitation
50–54	517	426 (82)	5177	4702 (91)
55–59	774	590 (76)	7677	6855 (89)
60–64	431	305 (71)	4289	3345 (78)
65–74	185	130 (70)	1835	1445 (79)
Period of index invitation
1992–1996	917	704 (77)	9123	7612 (83)
1997–2001	606	461 (76)	6024	5317 (88)
2002–2006	302	236 (78)	3011	2702 (90)
2007–2011	93	59 (63)	930	816 (88)
Follow-up time (years)
0–2.9	394	276 (70)	3913	3506 (89)
3–4.9	337	265 (79)	3376	3014 (89)
5–7.9	386	297 (77)	3824	3351 (87)
8–11.9	421	330 (78)	4188	3712 (88)
12–19.9	369	283 (77)	3677	2928 (79)

Note: Controls were categorised according to case's follow-up time category, that is, time from index invitation to death.