This study investigates how the design of weblinks in digital vaccination invitation emails influences recipient trust and their willingness to book an appointment. In this study, investigators compare three different link formats: a control third-party link previously used by the NHS, and two experimental weblinks: an improved version of the link, and a text embedded hyperlink.
The study tests primarily whether the two experimental weblinks will be perceived as more trustworthy and increase booking intention than the control weblink. Furthermore, the study examined whether the experimental weblinks are perceived to be more fluent (easier to read) and improve participants' ability to correctly identify the organisation (e.g., the NHS or a US pharmacy) that sent the hypothetical email.
To test these effects, investigators planned to gather data from 2,000 participants from the United Kingdom and 2,000 from the United States. They will be assigned to view one of the three hypothetical email versions. UK participants will see emails that appear to be from the NHS, while US participants see emails that appear to be from a local fictitious pharmacy. Due to US emails appearing to come from a fictitious pharmacy, investigators also expected that the benefit of correctly identifying the host organisation would be more pronounced in the United Kingdom than in the United States.
This research aims to provide evidence on how to design more effective and trustworthy digital health communications.