Do summaries of evidence enable informed decision-making about COVID-19 and influenza vaccination equitably across more and less disadvantaged groups? Study protocol for a multi-centre cluster randomised controlled trial of 'fact boxes' in health and social care in Germany.

INTRODUCTION

Evidence summaries on the benefits and harms of treatment options support informed decisions under controlled conditions. However, few studies have investigated how such formats support decision-making across different social groups. There is a risk that only disadvantaged people will be able to make informed health decisions-possibly increasing the health equity gap. It is also unclear whether they support decision-making in the field at all. The aim of our study is to assess whether evidence summaries based on the fact box format can help people from different social groups make informed decisions about COVID-19 and influenza vaccinations, and thus reduce inequity in health communication.

METHODS AND ANALYSIS

In a multi-centre, cluster-randomised, controlled trial, health educators from usual care and outreach work in Germany will be randomised in a 1:1 ratio to provide either usual health communication plus an evidence summary ('fact box') or usual health communication. Health educators provide a flyer about COVID-19 or influenza vaccination which contains a link to an online study either with (intervention) or without (control) fact box on the reverse side. Flyer and online study will be available in Arabic, German, Turkish and Russian language. The primary outcome is informed vaccination intention, based on vaccination knowledge, attitudes, intentions and behaviour. Secondary outcomes include risk perception, decisional conflict and shared decision-making. We will use linear mixed models to analyse the influence of both individual (eg, education status) and cluster level factors and account for the expected cluster variability in realising usual health communication or the intervention. The statistical analysis plan includes the selection of appropriate measures of effect size and power calculation, assuming a sample size of 800 patients.

ETHICS AND DISSEMINATION

The trial has been approved by the Ethics Committee of the University of Potsdam, Germany (application numbers: 34/2021 and 57/2022).Results will be disseminated through peer-reviewed journals, conferences and to relevant stakeholders.

PROTOCOL VERSION

Version 6 (4 October 2024); Preprint available on Research Square: https://doi.org/10.21203/rs.3.rs-3401234/v3 TRIAL REGISTRATION NUMBER: NCT06076421.