ABSTRACT
BACKGROUND: Human papillomavirus (HPV) vaccine should reduce cervical dysplasia before cervical cancer. However, dysplasia diagnosis is screening-dependent. Accurate screening estimates are needed. PURPOSE: To estimate the percentage of women in a geographic population that has had cervical cancer screening. METHODS: We analyzed claims data for (Papanicolau) Pap tests from 2008-2012 to estimate the percentage of insured women aged 18-39 years screened. We estimated screening in uninsured women by dividing the percentage of insured Behavioral Risk Factor Surveillance Survey respondents reporting previous-year testing by the percentage of uninsured respondents reporting previous-year testing, and multiplying this ratio by claims-based estimates of insured women with previous-year screening. We calculated a simple weighted average of the two estimates to estimate overall screening percentage. We estimated credible intervals using Monte-Carlo simulations. RESULTS: During 2008-2012, an annual average of 29.6% of women aged 18-39 years were screened. Screening increased from 2008 to 2009 in all age groups. During 2009-2012, the screening percentages decreased for all groups, but declined most in women aged 18-20 years, from 21.5% to 5.4%. Within age groups, compared to 2009, credible intervals did not overlap during 2011 (except age group 21-29 years) and 2012, and credible intervals in the 18-20 year group did not overlap with older groups in any year. CONCLUSIONS: This introduces a novel method to estimate population-level cervical cancer screening. Overall, percentage of women screened in Portland, Oregon fell following changes in screening recommendations released in 2009 and later modified in 2012.
