Self-reported HPV vaccination and vaccination record linkage in the Australian Oral Diversity Study

Australia has a school-based human papillomavirus (HPV) vaccination scheme that was implemented for girls in 2007 and for boys in 2013. HPV vaccination status is important for many studies into HPV infection. Here we wanted to estimate the validity of self-reported HPV vaccination status by comparing self-report to data from the national vaccination register.

Australian residents aged 18-70 years were recruited for the Oral Diversity Study from October 2020 to November 2021. Participants were asked to provide consent for record linkage to the Australian Immunisation Register (AIR). They were also asked to fill out a questionnaire about HPV vaccination, lifestyle, and sexual behavior.

1,023 participants were recruited, permission was received from 911 participants for HPV vaccination record linkage, and 850 self-reported vaccination and were part of the validity analysis. Of those 233 (26%) were confirmed to be HPV vaccinated. Ninety-one percent of the vaccinated were females (n = 212), 19 males and two non-binary. The highest HPV vaccine uptake was seen in the youngest age group (18-29 years; 80%), followed by 66% in 30-39 year olds, 2% in 40-49 year olds and then dropped significantly to 0.7% for people 50-70 years old. The sensitivity of self-report was 99.0%, and the specificity 94.5%, and the positive predictive value was 85.7% and the negative predictive value 99.7%.

We found that the correlation between self-reported Gardasil® vaccination and the AIR records were very good, with high sensitivity and specificity.