Table 1

Selected socio-demographic characteristics of study participants by country of residence

Mexico %US %P χ2
Age (yrs)
 15–191.810.6
 20–2414.319.8
 25–3440.434.0
 35–4429.323.7
 45–7914.311.9
Mean age (SD)34.3 (9.8)31.7 (10.4)<0.001
Age at first intercourse
 ≥2034.229.2
 18–1924.723.8
 16–1723.025.6
 6–1518.220.50.033
Lifetime no. of sex partners
 163.050.0
 2–327.326.9
 4–94.715.4
 >105.07.8<0.001
No. of new partners in past 3 mos.
 094.791.9
 13.46.4
 20.41.3
 3–601.50.4<0.001
Norplant history
 Never99.597.2
 Ever0.52.8<0.001
Injectable contraceptive history
 Never79.278.0
 Past15.714.2
 Current5.17.70.036
Marital status
 Married62.150.4
 Single10.127.9
 Cohabitating20.18.1
 Divorced/separated/widowed7.713.6<0.001
OC historya
 Never33.826.1
 Past50.541.8
 Current15.732.2<0.001
Smoking history
 Never75.668.5
 Past8.813.4
 Current15.618.1<0.001
Chlamydia trachomatis
 Negative91.392.7
 Positive8.77.30.218
  • a OC, oral contraceptive.