Table 1.

Characteristics of the study population.

	Cases		Controls			Cervical cancer rate per 100,000
	N	%	N	%	PYa 1000's
Total	4271	100%	8437	100%	34,756	12.3
Birth cohort
1928 to 1937	1312	31%	2596	31%	8906	14.7
1938 to 1947	1886	44%	3733	44%	16,446	11.5
1948 to 1956	1073	25%	2108	25%	9404	11.4
Age at diagnosis
60-64y	1254	29%	2477	29%	10,791	11.6
65-69y	1000	23%	1973	23%	9049	11.1
70-74y	804	19%	1583	19%	6672	12.1
75-79y	817	19%	1623	19%	5574	14.7
80-84y	396	9%	781	9%	2671	14.8
Screening status between age 60-64y
Screened	1528	36%	4885	58%	19,939	7.7
Not screened	2743	64%	3552	42%	14,817	18.5
Screening history between age 50-59y
None (born from 1938)	1424	33%	880	10%	3880	36.7
None (born 1928 to 1937)	573	13%	720	9%	2372	24.2
Abnormal screening	437	10%	450	5%	1898	23.0
Irregular screening	409	10%	912	11%	3921	10.4
One screen age 55-59y (born 1928 to 1937)	305	7%	733	9%	2483	12.3
Well screened	1123	26%	4742	56%	20,202	5.6
Screening participation
No screening	1856	43%	1309	16%	5267	35.2
Screened irregularly	1445	34%	3538	42%	14,472	10.0
Screened regularly	970	23%	3590	43%	15,169	6.4

^aPerson years.