Title: Human Papillomavirus Vaccination, Online Health Information Seeking, and Health Literacy among Transgender and Gender Nonbinary People
Description: BACKGROUND: Human Papillomavirus (HPV) is the most common sexually-transmitted infection in the U.S. and is associated with a number of cancers. A vaccine that can prevent 90% of HPV-associated cancers has been available since 2006, yet millions of young adults remain unvaccinated. Low vaccination uptake has been observed in cisgender sexual minority communities and less is known about HPV vaccination among transgender and gender nonbinary (TGNB) people. The aims of this dissertation were: (a) to identify facilitators for and barriers to HPV vaccination among gender minority people; (b) to compare HPV vaccination rates, HPV risk and situational factors like barriers to care, access to care, preventive care, HPV knowledge and Internet use in a sample of TGNB people and cisgender sexual minority people; and (c) to explore the association of online health information and HPV vaccination receipt among TGNB people compared to cisgender sexual minority people and determine if eHealth Literacy or general health literacy moderate this relationship.

METHODS: The dissertation comprised three studies. First, an integrative review of the literature included searches of three electronic databases to identify and appraise studies that explore patient-, provider- and system-level HPV vaccination barriers among gender minority people. Second, guided by the Integrative Model of eHealth Use, a cross-sectional secondary analysis of The Population Research in Identities and Disparities for Equality (PRIDE) Study Annual Questionnaire 2018-19, compared the rate of HPV vaccination among TGNB and cisgender sexual minority people and described situation factors (e.g., barriers to care, access to care, preventive care), Internet use, HPV knowledge, HPV risk, and HPV vaccination among these communities. Third, a novel cross-sectional online survey of TGNB and cisgender sexual minority participants recruited from The PRIDE Study, also guided by the Integrative Model of eHealth Use, explored the association between online health information seeking and receipt of HPV vaccine, and whether eHealth literacy and/or general health literacy moderate this relationship.

Statistical methods for the cross-sectional studies included prevalence ratios (PR) using robust Poisson statistics and multivariable logistic regression with post hoc Bonferroni-Holm correction. RESULTS: The integrative review identified six cross-sectional studies and one qualitative study that explored HPV vaccine barriers and facilitators among gender minority people. The majority of the studies included <10% gender minority participants. Key barriers to vaccination identified were misperceptions of risk at patient-level, bias towards vaccinating female assigned individuals at the provider-level and population effects of recommendations for girls-only at the policy-level. The cross-sectional secondary analysis of The PRIDE Study 2018-19 Annual Questionnaire and included N = 5,500 responses and found that: (a) the prevalence of ever receiving HPV vaccine was 1.2 times greater among TGNB participants than cisgender participants (PR 1.2; 95% CI, 1.1-1.3); (b) the prevalence of ever receiving HPV vaccine was 2.4 times greater among transgender men who were assigned female at birth compared to transgender women who were assigned male at birth (PR 2.4; 95% CI, 2.0-2.8); and (c) no differences in vaccination initiation and vaccination completion based on gender identity, sex assigned at birth, sex organs born with, or current sex organs.

The cross-sectional novel online survey of PRIDE participants yielded N = 3,258 responses (response rate 19.6%). After controlling for covariates including age, race/ethnicity and educational attainment, we found that TGNB as compared to cisgender participants had increased odds (aOR=1.5=; 95% CI, 1.1-2.2) of reporting receipt of HPV vaccine ever and decreased odds (aOR=0.7; 95% CI, 0.5-0.9) of ever receiving of HPV vaccine when they looked for info on vaccines in the past year. Conversely, TGNB participants had over twice the odds (aOR=2.4; 95% CI, 1.1-5.6) of ever receiving HPV vaccine if they visited a social networking site like Facebook or Instagram in the past year. There were no moderating effects observed from eHealth or general health literacy. CONCLUSIONS: TGNB communities are understudied in terms of HPV vaccination and the existing literature shows misperceptions about the need of HPV vaccination among TGNB communities at both the patient and provider level. TGNB participants were more likely to have ever received HPV vaccine compared to cisgender sexual minority participants in the cross-sectional secondary analysis of The PRIDE Study 2018-19 Annual Questionnaire which may be attributed to high primary engagement in the cohort.

Finally, online health information seeking about vaccines was associated with decreased receipt of HPV vaccine (ever) whereas social media use increased HPV vaccine receipt (ever) among TGNB participants compared to cisgender sexual minority participants. These conflicting findings suggest that the quality of online health information relating HPV vaccines, how, when and why TGNB people search for health information online may affect health behaviors like HPV vaccination. More research is warranted to explore how online health information seeking may influence personal health decision-making among TGNB communities.