title: Descriptive evidence that risk profiles for cervical intraepithelial neoplasia 1, 2, and 3 are unique.
abstract: OBJECTIVE
  This study aimed to estimate if risk factor profiles for histologically confirmed cervical intraepithelial neoplasia (CIN) 2 lesions differ from those for CIN 1 or 3.
  
  
  METHODS
  A total of 2,055 women positive for high-risk human papillomavirus, with a minimum of five cervical biopsies, were enrolled in the Shanxi Province Cervical Cancer Screening Study II. We evaluated risk factor profiles for CIN 2 in comparison with CIN 1 and 3. Polytomous logistic regression was used to generate odds ratios and corresponding 95% confidence intervals and to test for differences in odds ratios across histologic grades.
  
  
  RESULTS
  The risk for CIN 3 associated with three or more pregnancies and sexual intercourse within 4 months of childbirth was higher than that for CIN 2 (P(difference) = 0.02 and 0.0007, respectively). Significant differences in the associations of age groups with CIN 1 and 2 were observed, such that there were positive associations with CIN 2 but none for CIN 1. There was no difference in the association of number of sexual partners or reported number of abortions between CIN 1 and 2 or between CIN 3 and 2.
  
  
  CONCLUSIONS
  In our study, the patterns of risk factor profiles for CIN 1, 2, and 3 were unique. Conventional grouping of CIN 2 with 3 for analysis of risk factors may need revisiting.
authors.affiliation: Department of Preventive Medicine, Northwestern University, Chicago, IL 60622, USA. s-belinson@northwestern.edu
authors.forename: Suzanne
authors.initials: S
authors.lastname: Belinson
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Smith
authors.forename: Evan
authors.initials: E
authors.lastname: Myers
authors.forename: Andrew
authors.initials: A
authors.lastname: Olshan
authors.forename: Jerome
authors.initials: J
authors.lastname: Belinson
authors.forename: Robert
authors.initials: R
authors.lastname: Pretorius
authors.forename: You-lin
authors.initials: YL
authors.lastname: Qiao
authors.forename: Katherine
authors.initials: K
authors.lastname: Hartmann