Table 2

Prevalence of antibodies to HPV-16 VLPs among cases and controls by age, numbers of lifetime sexual partners, and age at first intercourse

Risk factorCasesControls
No. testedNo. (%) positiveORaNo. testedNo. (%) positiveORa
Age (yr)
 26–434725 (58)1.0 (ref)5419 (35)1.0 (ref)
 44–505224 (46)0.84913 (27)0.7
 51–604525 (56)1.15312 (23)0.5
 61–785018 (36)0.5619 (15)0.3
χ2 for trend, p = 0.18χ2 for trend, p = 0.011
No. sex partners
 071 (14)1.0 (ref)
 110335 (34)1.0 (ref)14122 (16)1.1
 24526 (58)2.73816 (42)4.4
 3169 (56)2.5197 (37)3.5
 ≥43022 (73)5.3127 (58)8.4
χ2 for trend, p < 0.001χ2 for trend, p < 0.001
Age, 1st intercourse
 <142715 (56)1.0 (ref)136 (41)1.0 (ref)
 15–1910451 (49)0.89424 (25)0.4
 ≥20 or virgin6326 (41)0.611023 (21)0.3
χ2 for trend, p = 0.18χ2 for trend, p = 0.08
  • a ORs are crude.