Table 1

Characteristics of 22-year-old women (n=913) who attended eight biannual follow-up visits and a subgroup of these women (n=197) who developed cervical atypia during 4 years of follow-up

Characteristics	Attendees		Women with atypia
Characteristics	n=913	%	n=197	%
Age
22	422	46.2	94	47.7
23	489	53.6	103	52.3
24	2	0.2	0	0
Missing	0	0	0	0
Age at menarche
≤11	194	21.3	52	26.4
12–14	659	72.2	136	69.0
≥15	52	5.7	6	3.10
Missing	8	0.8	3	1.5
Age at FSI
12–16	602	65.9	129	65.5
17–22	273	29.9	60	30.5
Missing	38	4.2	8	4.0
LNSPs
0	3	0.3	1	0.5
1	131	14.3	29	14.7
2–4	283	31.0	57	28.9
5–9	236	25.9	50	25.4
≥10	230	25.2	55	28.0
Missing	30	3.3	5	2.5
OC use
Non-user	62	6.8	15	7.6
User	842	92.2	179	90.9
Missing	9	1.0	3	1.5
Age at start of OC use
12–16	504	55.2	104	52.8
17–22	371	40.6	85	43.1
Missing	38	4.2	8	4.1
Condom use
Non-user	414	45.4	97	49.2
User	406	44.5	83	42.1
Don't know	76	8.3	16	8.1
Missing	17	1.8	1	0.5
Smoking
Never	525	57.5	108	54.8
Past	93	10.2	16	8.1
Present	291	31.9	73	37.1
Missing	4	0.4	0	0
HPV 16
Negative	711	77.9	145	73.6
Positive	201	22.0	52	26.4
HPV 18
Negative	792	86.8	165	83.8
Positive	120	13.1	32	16.2
Chlamydia
Negative	811	88.8	175	88.8
Positive	102	11.2	22	11.2

FSI, first sexual intercourse; HPV, human papillomavirus; LNSPs, lifetime number of sexual partners; OC, oral contraceptive.