Table 1. Characteristics of the premenopausal study population.

Characteristic	Cases (N=67)		Random controls (N=134)		HPV+controls (N=134)
Agea
Mean±s.d. (range)	34.3±6.9 (19–48)		34.6±6.6 (19–49)		33.4±7.4(18–50)
Live births
0–2	18	27.7	36	27.7	47	36.7
3–4	24	36.9	54	41.5	56	43.8
5–7	18	27.7	30	23.1	16	12.5
⩾8	5	7.7	10	7.7	9	7.0
Oral contraceptive use
Never	17	25.4	34	25.4	36	26.9
<2 years	20	29.9	34	25.4	47	35.1
2–4 years	14	20.9	33	24.6	24	17.9
⩾5 years	16	23.9	33	24.6	27	20.2
Lifetime sexual partners
1	23	34.3	65	48.5	52	38.8
2–3	27	40.3	45	33.6	58	43.3
⩾4	17	25.4	24	17.9	24	17.9
Lifetime Pap smears
0	8	11.9	7	5.2	12	9.0
1–2	14	20.9	30	22.4	34	25.4
3–5	21	31.3	51	38.1	46	34.3
⩾6	24	35.8	46	34.3	42	31.3
Smoking
Never	55	82.1	117	87.3	126	94.0
Ever	12	17.9	17	12.7	8	6.0
Tubal ligation
Never	47	70.2	78	58.2	94	70.2
<7 years ago	15	22.4	28	20.9	25	18.7
⩾7 years ago	5	7.5	28	20.9	15	11.2
Income (colones/year)
⩽14 999	12	17.9	27	20.2	26	19.4
15 000–24 999	19	28.4	27	20.2	29	21.6
25 000–44 999	18	26.9	40	29.9	35	26.1
⩾45 000	17	25.4	35	26.1	39	29.1
Unknown	1	1.5	5	3.7	5	3.7
HPV statusa
High risk	58	86.6	16	11.9	134	100.0
Low risk	4	6.0	25	18.7	0	0
Negative	5	7.5	93	69.4	0	0

^aMatching factor.