Parental intent to initiate and complete the human papillomavirus vaccine series in the USA: a nationwide, cross-sectional survey

Abstract

Background: Human papillomavirus (HPV) vaccine uptake among US adolescents is primarily dependent on the intent of their parents. To the best of our knowledge, an analysis quantifying parental intent to initiate and complete the HPV vaccine series in the USA at both the national and state level has not been done. We aim to estimate parental intent to initiate and complete the HPV vaccine series at the national-level and state-level and to identify reasons for lack of intent to initiate and complete the vaccine series.

Methods: This cross-sectional study uses data from the adolescent component of the 2017-18 National Immunization Survey (NIS-Teen). Study participants were parents or caregivers of US adolescents aged 13-17 years, who were most knowledgeable about the immunisation status of the adolescents. The primary outcome was parental intent to vaccinate the adolescent in the next 12 months. The secondary outcomes were (1) the prevalence of reasons given for lack of intent to initiate and complete the HPV vaccine series, and (2) the relationship between receiving a recommendation from a health-care provider to vaccinate and intent to initiate the vaccination series. We computed national-level and state-level estimates for parental lack of intent to initiate and to complete the vaccine series; population-level estimates were derived using survey weights. A survey design-adjusted Wald F test was used for bivariate analysis. A multivariate logistic regression model was used to examine the association between health-care provider recommendation and parental intent to initiate the series. Analyses were stratified by history of health-care provider recommendation to initiate the HPV vaccine series.

Findings: In 2017-18, the parent or caregiver of 82 297 US adolescents aged 13-17 years completed the NIS-Teen survey. 30 558 (37·1%) were unvaccinated and 9073 (10·8%) received only one HPV vaccine dose. Parents of 58·0% (17 171/29 086) of unvaccinated adolescents with data available on parental intent had no intention to initiate the HPV vaccine series. More than 65% of parents of unvaccinated adolescents in Idaho, Kansas, Michigan, Montana, Nebraska, North Dakota, Oklahoma, and Utah had no intention to initiate the HPV vaccine series. Parents of 23·5% (2166/9072) of initiators with data available on parental intent had no intention to complete the HPV vaccine series. More than 30% of parents in Arkansas, Florida, Georgia, Hawaii, Idaho, Utah, and West Virginia did not intend to complete the HPV vaccine series, whereas in the District of Columbia (11·2% [22/166]) and Rhode Island (20·4% [21/112]) parental lack of intent was relatively low (both regions have an HPV vaccine mandate). The most common reason for lack of intent among parents to initiate the vaccine for unvaccinated adolescents was safety concerns (22·8% [4182/16 455]); lack of a recommendation from a health-care provider (22·2% [440/1944]) was the most frequently cited reason for absence of intent to complete the series among parents of adolescents who received only one HPV vaccine dose. Receipt of a recommendation from a health-care provider was associated with greater odds of parental intent to initiate the HPV vaccine series (odds ratio 1·11, 95% CI 1·01-1·22). 45·5% (13 156/29 086) of parents of unvaccinated adolescents had reportedly received an HPV vaccine recommendation. Parents of 60·6% (7938/13 156) of unvaccinated adolescents with a recommendation from a health-care provider and data available on parental intent had no intention to initiate the series.

Interpretation: Lack of parental intent to initiate and complete the HPV vaccine series for adolescents is a major public health concern in the USA. Combating vaccine safety concerns and strong recommendations from health-care providers could improve the currently suboptimal HPV vaccination coverage.

Funding: US National Cancer Institute.

Copyright © 2020 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 license. Published by Elsevier Ltd.. All rights reserved.

Figures

FIGURE 1.. Number of US adolescents (overall, males, and females) by HPV vaccination status and parental intent to vaccinate, NIS-Teen 2017–2018.

The figure illustrates the total number of US adolescents aged 13–17 years by HPV vaccination status and parental intent to vaccinate. In 2017–2018 NIS-Teen, 37·1% (7·7 million of 20·8 million) US adolescents were unvaccinated and 10·8% (2·2 million of 20·8 million) received only one HPV vaccine dose (i.e., initiators). Parents of 58·0% (4·3 million of 7·3 million) unvaccinated adolescents did not intend to initiate the vaccine series (Panel A). These constitute of 2·3 million unvaccinated male adolescents (Panel B) and 1·9 million unvaccinated female adolescents (Panel C) whose parents do not intend to initiate the HPV vaccine series. Parents of 23·5% (0·5 million of 2·2 million) US adolescents who received only one HPV vaccine dose had no intention to complete the vaccine series (Panel A); these constitute of nearly 0·2 million adolescent males (Panel B) and 0·3 million adolescent females (Panel C) in the US with no parental intent to complete the series. Abbreviations: US, United States; HPV, human papillomavirus; NIS, National Immunization Survey *0 dose **1 dose only

FIGURE 2.. Parental lack of intent to initiate and complete the HPV vaccine series by states in the US, NIS-Teen 2017–2018.

The figure illustrates the proportion of unvaccinated and those who received only one HPV vaccine dose (i.e., initiators), and the proportion of parents with a lack of intent to vaccinate across US. Panel A illustrates the proportion of unvaccinated adolescents. Panel B illustrates parental lack of intent to initiate the HPV vaccine series. Panel C illustrates the proportion of adolescents who one dose only. Panel C illustrates parental lack of intent to complete the HPV vaccine series. Abbreviations: US, United States; HPV, human papillomavirus; NIS, National Immunization Survey

FIGURE 3.. Parental reasons for lack of intent to vaccinate by HPV vaccination status of the adolescent, NIS-Teen 2017–2018.

The figure illustrates the 28 reasons for lack of intent included in the NIS-Teen survey and the proportion of parents who responded ‘Yes’ for each listed reason. Parents were asked to identify the ‘main’ reason; therefore, responses are mutually exclusive. Panel A illustrates the main reasons for the overall adolescent population. The top reason for parental lack of intent to initiate the HPV vaccine in unvaccinated (i.e., received 0 HPV vaccine dose) adolescents was ‘safety concern’. The top reason for parental lack of intent to complete the series among initiators (i.e., received 1 HPV vaccine dose only) was ‘lack of a provider recommendation’. Panels B and C illustrate parental reasons for lack of intent to initiate versus to complete the series in male and female adolescents, respectively. Analyses were restricted to adolescents with information on parental reasons for no intent to vaccinate. Abbreviations: US, United States; HPV, human papillomavirus; NIS, National Immunization Survey. *0 dose **1 dose only

FIGURE 4.. Intent and top 5 reasons for lack of intent among parents of unvaccinated adolescents stratified by history of a provider recommendation to initiate the HPV vaccine series.

Panel A illustrates the number of US adolescents with no parental intent to vaccinate (2.0 million) despite a provider recommendation to initiate the HPV vaccine series (3·3 million); Panel B illustrates the top 5 reasons for no parental intent. Panel C illustrates the number of US adolescents with no parental intent to vaccinate (2·1 million) with no provider recommendation (3.7 million); Panel D illustrates the top 5 reasons for no parental intent.