Characteristics associated with non-initiation and non-completion of human papillomavirus vaccination among Danish girls: a nationwide register-based cohort study

Aim: The aim was to identify maternal and paternal socioeconomic and demographic characteristics for non-initiation and non-completion of the human papillomavirus (HPV) vaccination among Danish girls including time-trends. Methods: This nationwide register-based cohort study included all girls residing in Denmark who were offered free-of-charge HPV vaccination as a part of the childhood vaccination program between 2009 and 2018 (birth cohorts 1996–2005). The study samples included 296,461 daughter–mother dyads and 291,025 daughter–father dyads. Data from the Danish Vaccination Register were linked with socioeconomic and demographic data from Statistics Denmark. HPV vaccination status was classified as ‘non-initiation’ for girls who received no HPV vaccine and as ‘non-completion’ for girls who initiated the HPV vaccination program but did not receive all the scheduled HPV vaccines. Data were analyzed using logistic regression models. Results: Non-initiation of HPV vaccination was 13.7%, and non-completion was 24.2% among girls who initiated the HPV vaccination program. Girls of parents who were descendants of immigrants (adjusted odds ratio: 1.50; 95% confidence interval: 1.35–1.68), were at least 35-years old at time of birth, had basic or no education, had a low income, were not in the labor market, and were unmarried had the highest non-initiation and non-completion odds. The associations between socioeconomic and demographic characteristics and HPV vaccination uptake were similar for mothers and fathers. Conclusions: Despite free-of-charge availability to HPV vaccination in Denmark, we found disparities in non-initiation and non-completion of HPV vaccination among Danish girls by both mothers’ and fathers’ socioeconomic and demographic characteristics.