Randomized Controlled Trials of Personalized Digital Health Vaccination Decision Support

Formal decision support is one of the rare interventions shown to robustly increase voluntary vaccination. Decision aids are structured tools that provide evidence-based information and guidance to people making health-related decisions. They help people make better-informed health decisions and feel better about their decisions. Unlike purely informational health education, decision aids specifically support decision-making by making the decision explicit, providing balanced information on potential benefits and harms of options, and helping people clarify what matters to them (i.e., their values) relevant to the decision. Explicitly linking vaccine decisions to people’s values in a nonthreatening way is a promising strategy for encouraging vaccination.

Despite the promise of decision aids for encouraging vaccination, two major issues have limited their scope and impact in this clinical context. First, while most decision aids need only present potential harms and benefits to an individual (for example, the potential harms and benefits of options for treating knee pain), decision aids about vaccines should present both individual- and community-level benefits and harms. There is no established way to convey how individual vaccine decisions affect others, and vice versa. Second, decision aids like paper booklets for use in clinics are difficult to implement at scale and only reach those who make and attend appointments. We will solve both issues.

Our objective is to build complete decision aids about vaccination that include an avatar-based application we iteratively and rigorously developed, that uses personalized avatars to show how herd immunity protects one’s community, including those more vulnerable to infection. We will evaluate decision aids’ effectiveness in a Canadian context. Our study will provide evidence about the extent to which the decision aids work to increase vaccine acceptance and uptake and also the extent to which this digital health approach may be scaled up to reach the large majority of the Canadian population who have internet access (91% of people in Canada.


Julie Bettinger
Christine Chambers
Michelle Driedger
Ève Dubé
Doriane Étienne
Teresa Gavaruzzi
Anik Giguère
Hina Hakim
Noah Ivers
Julie Leask
Shannon MacDonald
Samantha Meyer
Ruth Ndjaboué
Jean-Sébastien Paquette
Beate Sander