AVPCancerFree: Impact of a Digital Behavior Change Intervention on Parental HPV Vaccine-Related Perceptions and Behaviors

"The findings have implications for the potential of digital behavioral change interventions like the HPVCF to influence parent decision-making and initiation of HPV vaccination."

Parental decisions to follow human papillomavirus (HPV) vaccination guidelines have been challenged by mixed messages and misinformation regarding HPV vaccines. Studies show that addressing factors that negatively affect parental vaccination decision-making is a key strategy to improving HPV vaccination rates. The HPVcancerfree app (HPVCF) was designed to assist United States (US) parents in making evidence-based decisions regarding HPV vaccination. This study examined if parents of vaccine-eligible youth (11-12 years of age) who use HPVCF in addition to usual care demonstrate significantly more positive intentions and attitudes toward HPV vaccination and greater HPV vaccination rates compared to those not using HPVCF.

Intended for use by English-speaking parents of HPV vaccine-eligible patients at Texas Children's Pediatrics (TCP) clinics, HPVCF is compatible with iOS and Android systems on mobile devices. The app was designed to provide parent educational content to reduce barriers and increase willingness to initiate HPV vaccination, to enable parents to record talking points regarding the HPV vaccine for discussion with the HCP at a future appointment, and to provide a reminder system for HPV vaccine dose appointments to promote completion of the series. HPVCF comprises four components accessible through tabs from the homepage: (i) 'HPV A-Z', a compendium providing facts about HPV and HPV vaccine, (ii) 'Bust A Myth', educational modules including peer and provider testimonials addressing salient HPV vaccination barriers, (iii) 'Notes 4 Doc', a medium to facilitate communication with providers on HPV vaccine, and (iv) 'Get the Vax', which enables parents to schedule tailored HPV vaccination appointment reminders.

HPVCF was developed based on behavioural theory and empirical evidence using a stepped programme planning framework, Intervention Mapping (IM). Its theoretical basis includes the Health Belief Model, Social Cognitive Theory, and Theory of Reasoned Action. IM guided identification of HPV vaccination behaviours and determinants of those behaviours: risk perception (knowledge, perceived susceptibility, perceived effectiveness), attitudes (intentions, outcome expectations, perceived barriers), self-efficacy, and perceived social norms. Prior to the RCT, usability testing was conducted with parents to establish the acceptability and perceived feasibility of HPVCF for implementation.

TCP clinics (n = 51) were randomly assigned to treatment (HPVCF + usual care) or comparison (usual care only) conditions in a pre- and posttest randomised, controlled trial (RCT) conducted between September 2017 and February 2019. Parents (n = 375) completed baseline and 5-month follow-up surveys.

Parents in the treatment (HPVCF) condition (n = 168) demonstrated significantly greater knowledge about HPV and HPV vaccine (p < .01) as well as perceived effectiveness of the HPV vaccine (p < .05) compared to parents in the comparison condition. Those parents also demonstrated higher initiation of Tdap and Meningococcal vaccination, greater knowledge about HPV-related disease, and more positive perceived norms, though these differences were not statistically significant. HPV vaccination initiation rates were not significantly different between parents in the treatment condition who used the HPVCF app and those in the comparison condition. A multivariate model to describe predictors of HPV vaccine initiation demonstrated an association with Tdap and Meningococcal vaccination adoption, positive change in perceived effectiveness of the HPV vaccine, and reduction in perceived barriers against HPV vaccination.

In discussing the findings, the researchers note that HPV vaccine initiation behaviour was not found to be significantly greater for parents who used HPVCF compared to those who did not. The psychosocial improvements found (e.g., with regard to knowledge and perceived norms) appeared to have been insufficient to significantly increase vaccination behaviour within the parameters of the study (although HPVCF use was associated with a strong trend toward greater initiation of Tdap and Meningococcal vaccines). The researchers speculate that a pre-post test period of 5 months may have been too short a duration to determine the influence of HPVCF on parental HPV vaccination behaviour.

The researchers suggest that the results obtained from HPVCF are encouraging when considering feasibility of reach and low burden on use (e.g., designed for brief and infrequent use). Future research could investigate the characteristics of parents most disposed to HPVCF, which may enable enhancement of HPVCF and development of promotional materials to broaden its appeal and attract those not naturally inclined to use it, including hesitant parents who may benefit the most from this supplemental education.

In conclusion: "HPVCF appears to be a feasible adjunct to the education received in usual care visits and may contribute to mitigating the influence of social media misinformation....Results reinforce the value of apps as adjunctive strategies to support the important persuasive voice of the HCP in overcoming parent hesitancy."