Table 2.

ORs and 95% CIs for having >1 sexual partner versus 1, and for age at first sexual intercourse less than 19 y versus 19 y or older among women without cervical cancer, by factors potentially relevant to risk of cervical cancer

CharacteristicsLifetime number of sexual partners
Age at first sexual intercourse
n
OR* (95% CI)n
OR (95% CI)
≥21<19≥19
All controls11,71118,69814,20415,370
Lifetime number of sexual partners
    16,60411,8701.00
    2-55,2182,9022.74 (2.57-2.92)
    ≥62,3825985.77 (5.09-6.53)
Age at first sexual intercourse (y)
    ≥253663,1571.00
    20-242,0316,7482.05 (1.79-2.34)
    17-194,5745,9634.50 (3.95-5.13)
    <174,1292,6068.75 (7.63-10.03)
Full-term pregnancies
    Nulliparous2,6401,6491.002,1412,1481.00
    <34,0366,6060.37 (0.32-0.43)4,3876,2552.58 (2.29-2.90)
    ≥34,41610,2110.24 (0.20-0.28)7,6676,9607.65 (6.74-8.68)
Age at first full-term pregnancy (y)
    Nulliparous2,6401,6491.002,1412,1481.00
    ≥251,9264,6060.60 (0.51-0.71)1,0765,4560.71 (0.62-0.82)
    19-243,7478,6400.23 (0.19-0.27)4,9067,4813.61 (3.18-4.10)
    <192,3273,1930.15 (0.13-0.19)5,5200
Study location
    Developing countries5,22613,6811.008,77810,1291.00
    Developed countries5,8744,7931.42 (1.26-1.59)5,4265,2410.81 (0.73-0.89)
Years of full-time education
    <104,85911,9201.008,6418,1381.00
    ≥105,9975,6041.36 (1.21-1.53)5,2896,3120.26 (0.24-0.28)
Hormonal contraceptive use
    Never4,20710,5711.006,3878,3911.00
    Ever6,8937,9031.19 (1.09-1.30)7,8176,9791.05 (0.99-1.12)
Condom use
    Never5,93214,0111.008,89111,0521.00
    Ever3,5273,0341.02 (0.91-1.14)3,3983,1630.75 (0.69-0.81)
Tobacco smoking
    Never5,1169,6461.006,5498,2131.00
    Past1,3577451.76 (1.48-2.09)1,2428601.45 (1.28-1.64)
    Current2,4481,2082.22 (1.92-2.56)2,4321,2241.77 (1.60-1.97)
History of Pap smear
    02,7898,8281.005,1256,4921.00
    ≥17,0939,0200.98 (0.89-1.09)7,8558,2580.88 (0.82-0.95)
  • NOTE: Overall there were 30,409 controls; however, information was not available from all studies for all variables.

  • * Conditioned on age, study, and age at first sexual intercourse.

  • Conditioned on age, study, and lifetime number of sexual partners.

  • Median age at first sexual intercourse among controls is 19 y.