Importance Human papillomavirus (HPV) vaccination prevents multiple cancers, yet vaccination rates by the recommended age remain well below national goals. Objective To evaluate the effectiveness of a multicomponent strategy in increasing HPV vaccination rates in primary care settings by 13 years of age. Design, Setting, and Participants This cluster randomized clinical trial with a parallel-group design and 1:1 allocation was conducted at 20 pediatrics primary care practices from a practice-based research network in the St Louis, Missouri, metropolitan area by clinicians delivering routine well-child visits within participating practices. The intervention was implemented over 24 months (July 1, 2020, to September 30, 2022) with follow-up at 36 months (July 1, 2022, to September 30, 2023; 12 months after the intervention). Baseline characteristics were assessed using 2019 data. Interventions (1) Practice facilitation by a trained external facilitator, (2) audit and feedback of HPV vaccination rates, (3) HPV vaccination education, and (4) announcement-style communication strategy. Main Outcomes and Measures The primary outcomes were the proportion of patients who received the first HPV vaccine (initiation) and completed the series (completion) by 13 years of age, assessed at 24 months. Enduring effect was assessed at 36 months. Data were analyzed based on the intention-to-treat principle. Results A total of 86 clinicians participated (40 control and 46 intervention; 65 women 75.6%). Most were physicians (67 77.9%) and median time in practice was 18 years (IQR, 10-24 years). The intervention group had a higher percentage of privately insured patients than the control group (1562 of 1727 90.4% vs 717 of 1371 52.3%). At 24 months, HPV vaccination initiation rates were 80.1% (1723 of 2151) in the intervention group vs 75.5% (1219 of 1615) in the control group; completion rates were 52.8% (1135 of 2151) in the intervention group vs 50.1% (809 of 1615) in the control group. At 36 months, initiation rates were 82.0% (1812 of 2211) in the intervention group vs 74.6% (1052 of 1410) in the control group; completion rates were 57.8% (1279 of 2211) in the intervention group vs 49.9% (703 of 1410) in the control group. Fully adjusted models showed no differences for vaccination initiation (24 months: odds ratio OR, 1.15 95% CI, 0.78-1.70; 36 months: OR, 1.42 95% CI, 0.96-2.11) or completion (24 months: OR, 0.96 95% CI, 0.72-1.29; 36 months: OR, 1.24 95% CI, 0.92-1.67), although intervention effects for initiation increased significantly over time ( P = .04). Conclusions and Relevance In this cluster randomized clinical trial of a multicomponent intervention in 20 practices, HPV vaccination rates by 13 years of age were not significantly different between groups, although intervention effects increased significantly over time for initiation of vaccination. System-focused interventions may require extended evaluation periods to demonstrate measurable improvements. Trial Registration ClinicalTrials.gov Identifier: NCT04180462
Wang et al. (Thu,) studied this question.