Prevalence of human papillomavirus among females older than recommended age for vaccination by birth cohort, United States 2003‒2016.

BACKGROUND Apparent associations between HPV prevalence and age observed in cross-sectional studies could be misleading if cohort effects influence HPV detection. METHODS Using data from 2003-2016 National Health and Nutrition Examination Surveys (NHANES), we evaluated overall and 10-year birth cohort-specific cervicovaginal HPV prevalence estimates (any, high-risk [HR], and non-HR) by 3-year age group among 27-59 year-old females born in 1950-1979. Average percent changes (APC) in HPV prevalence by 3-year age were calculated using prevalence ratios from log-binomial models. RESULTS Overall, prevalence of any HPV declined from 49.9% in 27-29 year-olds to 33.8% in 57-59 year-olds [APC: -2.82% per 3-year age group, 95% confidence interval (CI): -4.02%, -1.60%] as did prevalence of HR-HPV [APC: -6.19% (95% CI: -8.09%, -4.26%)] and non-HR-HPV [APC: -2.00% (95% CI: -3.48%, -0.51%)]. By birth cohort, declines by age group were seen in prevalences of any HPV, HR-HPV, and non-HR-HPV for those born in the 1950s and 1970s and in any HPV and HR-HPV for those born in the 1960s (APC range: -14.08% - 0.06%). CONCLUSIONS Declines in HPV prevalence with age in these cross-sectional surveys cannot be explained by birth cohort differences alone, as associations were observed across all birth cohorts. These findings are consistent with biological and behavioral explanations.