title: Reduction in cervical intraepithelial neoplasia in young women in British Columbia after introduction of the HPV vaccine: An ecological analysis.
abstract: We report on the rates of cervical intraepithelial neoplasia (CIN) in young women aged 15-22 years of age in British Columbia before and after the introduction of an HPV vaccine program. Rates of cervical intraepithelial neoplasia (CIN) 2+ for each age stratum (15-22) in the calendar years 2004-2012 for the province of British Columbia were obtained from the BC Cancer Agency's population-based cervical cancer program. Incidence rate ratios (IRR) of CIN2+ were described and compared before and after HPV vaccine program introduction in cohorts born in vaccine eligible years, and in non-vaccine eligible years using piece-wise Poisson regression analysis, and adjusted for age. Between 2004 and 2012, rates of CIN2 and CIN2+ in young women aged 15-22 years in the province of British Columbia have decreased overall. After the introduction of the HPV vaccine program, the age adjusted IRR for CIN2+ for young women aged 15-17 years decreased significantly from 0.91 (95% CI: 0.86-0.98 p < 0.01) to 0.36 (95% CI: 0.18-0.73 p < 0.01). During the same time period, no similar reduction was found in young women 18-22 years. After introduction of HPV vaccine program, IRR for CIN2+ in young women 15-17 was significantly reduced for CIN2+ (0.14; 95% CI: 0.04- 0.47; p < 0.01) and CIN2 (0.1; 95% CI: 0.02-0.54; p < 0.01). This ecological analysis shows a significant reduction in CIN2+ lesions in young women aged 15-17 years in British Columbia after the introduction of the HPV vaccine in young women despite vaccine uptake levels below 70%.
authors.affiliation: Faculty of Medicine, University of British Columbia, Woodward Instructional Resource Centre, Vancouver, BC, Canada.|British Columbia Centre for Disease Control, Vancouver, BC, Canada.
authors.forename: Gina S
authors.initials: GS
authors.lastname: Ogilvie
authors.affiliation: Faculty of Medicine, University of British Columbia, Woodward Instructional Resource Centre, Vancouver, BC, Canada.|British Columbia Centre for Disease Control, Vancouver, BC, Canada.
authors.forename: Monika
authors.initials: M
authors.lastname: Naus
authors.affiliation: Faculty of Medicine, University of British Columbia, Woodward Instructional Resource Centre, Vancouver, BC, Canada.|British Columbia Women's Hospital and Health Centre, Vancouver, BC, Canada.
authors.forename: Deborah M
authors.initials: DM
authors.lastname: Money
authors.affiliation: Faculty of Medicine, University of British Columbia, Woodward Instructional Resource Centre, Vancouver, BC, Canada.|British Columbia Children's Hospital, Vancouver, BC, Canada.
authors.forename: Simon R
authors.initials: SR
authors.lastname: Dobson
authors.affiliation: Faculty of Medicine, University of British Columbia, Woodward Instructional Resource Centre, Vancouver, BC, Canada.|British Columbia Cancer Agency, Vancouver, BC, Canada.
authors.forename: Dianne
authors.initials: D
authors.lastname: Miller
authors.affiliation: Faculty of Medicine, University of British Columbia, Woodward Instructional Resource Centre, Vancouver, BC, Canada.|British Columbia Centre for Disease Control, Vancouver, BC, Canada.
authors.forename: Mel
authors.initials: M
authors.lastname: Krajden
authors.affiliation: British Columbia Cancer Agency, Vancouver, BC, Canada.
authors.forename: Dirk J
authors.initials: DJ
authors.lastname: van Niekerk
authors.affiliation: British Columbia Cancer Agency, Vancouver, BC, Canada.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Coldman
mesh_terms: D000293:Adolescent; D000328:Adult; D001955:British Columbia / Q000453:epidemiology; D005260:Female; D006801:Humans; D030361:Papillomavirus Infections / Q000517:prevention & control*; D053918:Papillomavirus Vaccines / Q000627:therapeutic use*; D012044:Regression Analysis; D002583:Uterine Cervical Neoplasms / Q000453:epidemiology* / Q000517:prevention & control / Q000821:virology; D055815:Young Adult; D002578:Uterine Cervical Dysplasia / Q000453:epidemiology* / Q000517:prevention & control / Q000821:virology
chemical_list: D053918:Papillomavirus Vaccines
keywords: HPV vaccine; cervical intraepithelial neoplasia; human papillomavirus; primary cancer prevention; vaccination program