Co-design and user testing of a Japanese encephalitis vaccine decision aid (JEVaDA).

Background: Japanese encephalitis (JE) is a rare but potentially serious infection in travellers. While effective vaccines are available, uptake remains low. Vaccine decision aids are evidence-based tools designed to help users make informed vaccination decisions. This study details the development of a novel web-based Japanese encephalitis vaccine decision aid (JEVaDA) for travellers, following globally recognised standards.

Methods: Collaborating with community members, healthcare providers and experts, we followed a multi-step approach, involving a scoping review, a survey of user needs, co-design workshops, user testing, and expert review. Findings from workshops and testing informed the development of decision aid prototypes, with input from a graphic designer. We used the Patient Education Materials Assessment Tool to assess understandability and actionability and the Ottawa acceptability tool to measure components of acceptability. The final version was adapted to a web-based format.

Results: Five co-design workshops conducted with 16 participants (nine community members, seven healthcare providers) gathered input and feedback on the initial PDF prototype. The refined prototype was user-tested by another group of 22 participants (16 community members, six healthcare providers) and reviewed by five subject matter experts. Feedback indicated areas for improvement in risk visualisation, personalised content, and catering to diverse user needs. The decision aid scored highly for understandability (89 %) and actionability (87 %). All participants (100 %) found it suitable for decision making.

Conclusion: We successfully co-designed and user-tested a JE vaccine decision aid with community members, healthcare providers and experts. The interactive, web-based version is now freely available at www.monash.edu/vaccinedecisionaids-je.