In 2009, the Dutch government started a nationwide human papillomavirus (HPV)-vaccination program (i.e., three vaccinations) for 12-year-old girls to prevent cervical cancer. The uptake (58%) is still much lower than expected. Research indicated that mothers played the most important role in the immunization decision of these girls. Socio-cognitive determinants largely (80%) contributed to the explained variance of the HPV-vaccination decision of mothers. Besides, a large proportion of the mothers did not actively process information about the HPV-vaccination and felt ambivalent about their final decision. Because informed decision making will make mothers less vulnerable for counter arguments, mothers need structured support for their decision making. Such an intervention should be interactive and tailored, because mothers indicated their preference for personal interaction over and above the usually applied general approach, and because they expressed differential needs concerning the amount and scope of information. The current project aims to develop and evaluate the effects of a tailored intervention providing mothers of girls-to-be-invited with interactive feedback from a virtual assistant on the possible HPV-vaccination of their daughter.
COMPUTER TAILORING BY A VIRTUAL ASSISTANT
Computer tailoring has proven to be an effective strategy for health-related behaviors. The effects have been attributed to greater message attention and acceptance. Computer-tailored interventions can reach large groups of people at relatively low costs, and have substantial impact at the population level. This especially accounts for second-generation (i.e., web-based) tailored feedback. So far, tailored interventions to promote vaccine uptake do not exist. The intended feedback will be delivered by a virtual assistant, because this already showed effects in the field of stress management and health-related self-management.
1) What is the efficacy and effectiveness of an interactive web-based tailored feedback on HVP-vaccination uptake of participants’ daughters (primary outcome), on the mothers’ informed decision making and related determinants (secondary outcomes) regarding the HPV-vaccination of their daughter?
2) To what extent are mothers exposed to the planned intervention components (program adherence), and what is their subjective evaluation of the feedback?
3) What is the response rate of mothers from the National Immunization Register to the invitation to visit the web-site for receiving interactive support for their decision making about the HPV-vaccination of their daughter?
The effects will be tested by an RCT among two samples of participants: (1) derived from an internet panel for efficacy testing, and (2) derived from Praeventis, the National Immunization Register (i.e., ‘naturalistic sample’), for effectiveness testing. The primary outcome will be requested once from Praeventis (after closure of the vaccination round). Secondary outcomes will be measured at baseline (prior to the first vaccination) and follow-up (during the first vaccination). The rate of response to the invitation to visit the web-based feedback will be assessed among the ‘naturalistic sample’. A process evaluation will assess feasibility and program adherence.
Development of the proposed intervention is a logical step after the recently completed empirical studies by the project team on (determinants of) the HPV-vaccination acceptability. We propose a three-stage process of development:
1) Preparation: Literature review, intervention development and pretests, and consultation of experts, mothers and girls-to-be-invited.
2) Field experiment: Data collection at baseline and follow-up. After baseline, a random sample drawn from both a ‘naturalistic sample’ and an internet panel will be exposed to the intervention. HPV-vaccination uptake behavior will be requested from the Praeventis after closure of the HPV-vaccination round.
3) Completion and dissemination: Data-analyses, report