Date of Award
Spring 2024
Document Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Public Health
First Advisor
Niccolai, Linda
Abstract
Health care provider (HCP) recommendations are a key predictor of vaccineacceptance among parents of adolescents. However, HCP recommendations for adolescent vaccines are not universal. In order to address disparities in HCP recommendations, we must first understand why recommendations vary. The factors that influence a HCP recommendation are multilevel. At the individual level, a HCP’s own knowledge, attitudes and beliefs about a vaccine can influence how or if they recommend the vaccine to a patient. At the interpersonal level, the characteristics of the patient can impact how a HCP perceives disease risk or need for a vaccine in their patient. At the community level, the characteristics of the neighborhood in which the HCP practices may influence their ability or inclination to recommend a vaccine. Lastly, state vaccine requirements and vaccine financing policies can also influence a HCP recommendation. This dissertation aims to first explore the different factors that may influence a HCP recommendation and second move towards action by providing information that can be used to address the disparities in recommendation practices influenced by these factors. Chapters 1 and 2 describe research aimed at understanding how HCP recommendations may vary at the community and individual level, respectively. Chapter 3 presents the results of a systematic review that can be used to address disparities in provider recommendations of the HPV vaccine. In Chapter 1, I utilized nationally representative data from the National Immunization Survey – Teen (NIS Teen) and the Census Bureau to examine the association between community level socioeconomic factors and receipt of a recommendation for the human papillomavirus (HPV) vaccine. I conducted a multilevel multivariable weighted logistic regression to examine these associations at the zip code level and found that receipt of a recommendation for the HPV vaccine varied by socioeconomic factors including community level population density, percent unemployment and education. Additionally, there was interaction between adolescent race/ethnicity and area level poverty; non-White adolescents living in high poverty zip codes were 1.16 times more likely to have received a recommendation for the HPV vaccine than White adolescents living in high poverty zip codes (95% CI = 1.02, 1.32). These findings can inform where interventions to address disparities in HCP recommendations should be targeted. In Chapter 2, I present the results of a survey of adolescent HCP in Connecticut about their individual level attitudes about and perspectives on the pentavalent meningococcal vaccine (MenABCWY) which was recently approved by the Food and Drug Administration (FDA) and recommended by the Advisory Committee on Immunization Practices (ACIP) in October 2023. Approximately 75% of respondents were only somewhat aware or not at all aware of the pentavalent vaccine. When asked about potential new meningococcal vaccine recommendations incorporating the pentavalent vaccine, respondents were most strongly in favor of a recommendation that indicated use of only the pentavalent vaccine in place of any of the current recommended doses of the quadrivalent (MenACWY) or the serogroup B vaccine (MenB). However, many HCP were also in favor of any recommendation that indicated to replace only one or two of the currently recommended doses with the pentavalent vaccine. These findings can be used to inform the current reevaluation of the meningococcal vaccine schedule for adolescents as well as interventions to improve meningococcal vaccine recommendations among adolescent HCP. Lastly, in Chapter 3 I conducted a systematic review of HPV vaccine effectiveness by age at administration. A key component of a high-quality recommendation for the HPV vaccine is timely administration (i.e. by ages 11-12); however, many HCP delay vaccination and many adolescents are not vaccinated prior to being exposed to HPV. In this review, I found that the HPV vaccine is highly effective when initiated at younger ages (74%-93% effective when initiated between ages 9 – 14) but less effective when initiated later in adolescence (12%-90% effective when initiated between the ages of 15- 18). These results emphasize the importance of on time vaccination and can be used to support interventions to reduce delaying HPV vaccine initiation and encourage on time HPV recommendations among HCP. This dissertation provides insight into several key areas of intervention and further research to address disparities in HCP recommendation practices. First, we found meaningful variation at the community level for recommendations of the HPV vaccine that may reflect inequities in how HCP perceive risk of disease among their patients and subsequently, who they believe needs to be vaccinated. Further work is needed to understand the mechanism behind this variation at the community level; however, the findings of this study can be used to guide targeted interventions. Second, our findings demonstrate that HCP perspectives about vaccine recommendations do vary at the individual level for meningococcal vaccines; however, more information is needed to better understand this variation at the national level as well as how attitudes may vary for other adolescent vaccines. Lastly, our findings reflect the importance of understanding the factors driving HCP recommendations in policy and decision-making around adolescent vaccination, such as the recommended age of initiation for the HPV vaccine.
Recommended Citation
Ellingson, Mallory Kathryn, "Identifying the Multilevel Factors Influencing Provider Recommendations for Adolescent Vaccines" (2024). Yale Graduate School of Arts and Sciences Dissertations. 1373.
https://elischolar.library.yale.edu/gsas_dissertations/1373
