Association between Parent Attitudes and Receipt of Human Papillomavirus Vaccine in Adolescents

Human papillomavirus (HPV) vaccine series completion is low, at approximately 35% in the United States (US). While multiple causes likely exist, low coverage is thought to be a function of parental hesitancies, ambivalence, or resistance. The purpose of this study was to examine the association between changes in parents' HPV vaccine attitudes and HPV vaccine uptake in their adolescents, using electronic health records (EHR) data from a north-central Wisconsin, US, integrated healthcare system. The hypothesis was that positive changes in parental attitudes would be associated with greater adolescent HPV vaccine uptake.

A baseline and 1-year follow-up survey of HPV vaccine attitudes was administered to parents of 11-16 year olds who had not completed the HPV vaccine series. Changes in attitudinal scores (barriers, harms, ineffectiveness, and uncertainties) from the Carolina HPV Immunization Attitudes and Beliefs Scale (CHIAS) were assessed. Two outcomes were measured (in parents' adolescent children) over an 18-month period and analysed using multivariable regression: receipt of next scheduled HPV vaccine dose and 3-dose series completion.

There were 221 parents who completed the baseline survey (11% response rate) and 164 with available follow-up data. At baseline, 32% of parents' adolescent children had initiated the HPV vaccine, having received 1-2 prior HPV vaccine doses (none had completed the 3-dose series, per study eligibility criteria). Sixty percent of parents' adolescent children (58% of males, 62% of females) had received at least 1 HPV vaccine dose, and 38% (44% of males, 33% of females) had completed the 3-dose series by the end of the 18-month follow-up period. The highest baseline CHIAS sub-factor scores were for harms (mean ± SD = 2.2 ± 0.6 points) and uncertainties (2.2 ± 0.7 points), followed by ineffectiveness (2.1 ± 0.9 points), and barriers (1.4 ± 0.4 points). Barriers and harms scores remained stable over time. Scores for uncertainties and ineffectiveness improved, both decreasing by 0.2 points (~10% improvement; p's < 0.001) over 1 year.

At the 1-year follow-up survey, 77% of parents reported having received a physician's recommendation for their adolescent child to get the HPV vaccine in the prior year, and such a recommendation was associated with receiving the next HPV vaccine dose.

Decrease in parents' uncertainties was a significant predictor of vaccine receipt, with each 1-point reduction in uncertainties score associated with 4.9 higher odds of receipt of the next vaccine dose. Only baseline concerns about vaccine harms were associated with lower series completion rate; it seemed parents with high harms scores were not apt to change their minds, and even if they did, it had no impact on HPV vaccine receipt.

These findings suggest that public awareness and patient education interventions should emphasise the HPV vaccine's post-licensure safety profile. One clinical implication could be that, compared to brief/straightforward recommendations, more in-depth conversational approaches by medical providers may yield limited influence on parents' decision-making regarding HPV vaccination. Along those lines, the researchers conclude: "Given the positive influence of medical providers' advice on parents' HPV vaccine decisions in prior studies..., as well as our current study, the healthcare system appears to be an optimal setting to test future methods to improve HPV vaccine attitudes and coverage."