Clinician Training, Text Messages, and Human Papillomavirus Vaccination Among Children Aged 10 to 12 Years: A Randomized Clinical Trial

Importance Human papillomavirus (HPV) vaccination rates among adolescents remain below recommendations. Objective To evaluate the effectiveness of clinician communication training and parent-targeted text messages at increasing HPV vaccination among children aged 11 to 12 years. Design, Setting, and Participants This doubly randomized, 2-level nested clinical trial was conducted from February 2022 to September 2024 among clinicians at 30 pediatric primary care clinics in Florida, children aged 10 to 12 years who had not received any of the 3 adolescent HPV vaccines, and their parents. Interventions occurred for 1 year, and vaccine records were collected for 2 years. Interventions Clinics were randomized 1:1:1 to 3 training groups: (1) the bundled approach, which presents the HPV vaccine in the middle of 2 other recommended vaccines; (2) the focused approach, which emphasizes cancer prevention; and (3) deferred, which offered clinicians the opportunity to participate in the focused training after the trial concluded. Clinicians in the first 2 groups completed a 1-hour communication training and a 5-minute booster session. Patients within clinics were randomized 1:1:1 to 3 text message groups, aligned with the communication strategies: (1) bundled, (2) focused, and (3) no text messages. Parents were sent text messages at the start of the study or prior to their child’s 11th birthday as well as prior to appointments. Main Outcomes and Measures Primary outcomes were HPV vaccine initiation (receipt of first dose) and completion (receipt of second dose). Analyses accounted for clinic-level clustering. Effects were analyzed as randomized and text messages as received. Results At baseline, 59 clinicians (44 [75%] female; 12 [20%] Asian, 21 [36%] Hispanic, and 21 [36%] non-Hispanic White) within 30 randomized clinics were included, with 17 randomized to the focused group, 21 to the bundled group, and 21 to the deferred group. A total of 7234 children were aged 10 (3576 [49%]), 11 (2617 [36%]), and 12 (1041 [14%]) years at study start (1673 [23%] Hispanic, 1001 [14%] non-Hispanic Black, and 1210 [17%] non-Hispanic White). A total of 28 clinics (93%), 50 clinicians (85%), and 6498 children (90%) completed the 2-year follow-up. The mean pre-post clinic-level difference for HPV vaccine initiation was 28.2 (95% CI, 25.3-31.1) percentage points and for completion was 16.1 (95% CI, 13.3-18.9) percentage points. Risk ratios for clinician training and text messaging did not differ between groups for initiation or completion. Among patients whose parents received text messages vs not, the risk ratio for initiation was 1.17 (95% CI, 1.08-1.26) and for completion was 1.29 (95% CI, 1.06-1.56). Conclusions and Relevance In this study of Florida children aged 10 to 12 years, clinic-level HPV vaccination increased over time. No differences in HPV vaccination by random assignment of clinician training or text messages were detected. When received, text messages were associated with higher HPV vaccination. Trial Registration ClinicalTrials.gov Identifier: NCT05006833