Human Papillomavirus Vaccine Administration Trends Among Commercially Insured US Adults Aged 27-45 Years Before and After Advisory Committee on Immunization Practices Recommendation Change, 2007-2020.

Importance: In 2019, the Advisory Committee on Immunization Practices (ACIP) recommended patient-clinician shared decision-making for human papillomavirus (HPV) vaccination in adults aged 27 to 45 years. Less is known about the HPV vaccine administration trends in this age group before and after this recommendation update. Objective: To examine the association between the ACIP recommendation update and the HPV vaccine administration among US adults aged 27 to 45 years. Design, Setting, and Participants: This large commercial claim-based retrospective cohort study used the Optum Clinformatics database for validated claims from January 1, 2007, through December 31, 2020. A total of 22 600 520 US adults aged 27 to 45 years without previous HPV vaccination claims during the study and enrollment period were included. Main Outcomes and Measures: The first-appearing HPV vaccination claim per individual was defined as a new HPV vaccine administration. Interrupted time-series analyses were conducted to assess the association between the ACIP update and the quarterly vaccine administration rate change. The annual rate trends across race and ethnicity groups and the proportions of vaccination cases by sub-age groups and valent types were also estimated. Vaccine administration trends were assessed by race and ethnicity in this age group because HPV vaccination trends were found to differ by race and ethnicity in the initially eligible population. Results: Among 22 600 520 final study participants, the majority were men (50.9%) and non-Hispanic White (53.4%), and the mean (SD) age when first observed was 34.6 (5.8) years. In women, the ACIP update was associated with an immediate increase in vaccine administration rate (coefficient β2, 40.18 per 100 000 persons; P = .01) and an increased slope (coefficient β3, 9.62 per 100 000 persons per quarter; P = .03) over time postupdate. The ACIP update was only associated with an immediate increase in vaccine administration in men (coefficient β2, 27.54; P < .001). The annual rate trends were similar across race and ethnicity groups. Age at vaccine administration shifted over time (eg, women aged 40-45 years comprised only 4.9% of vaccinations in 2017, then 19.0% in 2019, and 22.7% in 2020). The most administered HPV vaccines in 2020 were 9 valent (women, 97.0%; men, 97.7%). Conclusions and Relevance: In this population-based cohort study, there were statistically significant increases in HPV vaccine administration in adults aged 27 to 45 years after the ACIP recommendation update. Patient-clinician shared decision-making may have been the main associated factor for this increase. Further research is warranted to explore the decision-making process in receiving HPV vaccination and to develop effective decision aids to maximize the cancer prevention benefit in this age group.