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Reduction in cervical intraepithelial neoplasia in young women in B ritish C olumbia after introduction of the HPV vaccine: An ecological analysis
Author(s) -
Ogilvie Gina S.,
Naus Monika,
Money Deborah M.,
Dobson Simon R.,
Miller Dianne,
Krajden Mel,
van Niekerk Dirk J.,
Coldman Andrew J.
Publication year - 2015
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/ijc.29508
Subject(s) - cervical intraepithelial neoplasia , medicine , poisson regression , cervical cancer , gynecology , demography , population , rate ratio , incidence (geometry) , intraepithelial neoplasia , young adult , cancer , environmental health , prostate , physics , sociology , optics
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%.