Background and objectives: Although HPV vaccine initiation as early as aged 9 years has been recommended, most clinicians initiate at ages 11 to 12 years. We assessed clinician-reported impact of early initiation on parental responses and vaccine discussions.
Methods: As part of an ongoing cluster randomized pragmatic trial across 31 Colorado and California pediatric practices, we allocated practices to switch HPV vaccine initiation to ages 9 to 10 years or to enhanced usual care (initiation at ages 11 to 12 years). All clinicians received online training on improving HPV vaccination; intervention arm clinicians also received training on initiating at ages 9 to 10 years. We surveyed all clinicians in both arms at 1, 6, 12, 18, 24, 30, and 36 months (all >80% response rates), and queried clinicians in the ages 9 to 10 years arm about vaccination at ages 9 to 10 vs 11 to 12 years.
Results: Almost all intervention arm clinicians switched rapidly to the ages 9 to 10 years initiation; most control clinicians remained at ages 11 to 12 years. Parental concerns/questions, pushback, hesitancy, and adherence to recommendations did not differ significantly between study arms and were similar at ages 9 to 10 vs 11 to 12 years among intervention arm clinicians. Only about one-tenth of clinicians in both arms brought up sexual activity during HPV vaccine discussions; two-thirds in both arms indicated parents sometimes/often did. Intervention arm clinicians were more likely than controls to state discussions were shorter by a lot/little (55% vs 37%, P = .005) since study initiation.
Conclusions: Initiating HPV vaccination at ages 9 to 10 years instead of ages 11 to 12 years had little impact on parental questions/concerns, pushback, hesitancy, or clinicians' ability to convince hesitant parents. Initiation at ages 9 to 10 years was perceived by clinicians to shorten HPV vaccine discussions.
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