Table 1.

Characteristics of the participants.

	Adenocarcinoma in situ		Invasive adenocarcinoma
	Cases	Controls	Cases	Controls
Number of study subjects	118	118	164	164
Age at diagnosis1	36 (20 – 60)	36 (19 – 61)	43 (24 – 88)	43 (24 – 88)
Age at entry	27 (16 – 57)	28 (16 – 57)	36.5 (17 – 82)	36 (17 – 81)
Study time	7.3 (1 – 26)	7.45 (1 – 25.9)	6.1 (1 – 21.1)	5.9 (1 – 21.3)
Number of smears	373	324	392	345
Median no. of smears per subject	3 (1 – 13)	2 (1 – 12)	2 (1 – 9)	2 (1 – 8)

¹Median age and study time in years (range).