Impact assessment of dissemination techniques on data collection in a large multicenter Healthy Brain Ageing (HeBA) survey (Preprint)

<sec> <title>BACKGROUND</title> Innovative approaches are important for the early detection of Parkinson's disease (PD) and include large-scale online surveys on different risk factors in the general population. Effective dissemination contributes to the success of such studies, but little is known about the reach and cost related to different strategies. </sec> <sec> <title>OBJECTIVE</title> This study aims to characterize and compare the dissemination strategies employed in the multicenter Healthy Brain Ageing (HeBA) study, with particular focus on the effectiveness of digital and traditional media in engaging diverse populations across three European centers. </sec> <sec> <title>METHODS</title> Data from the multicenter HeBA study aiming at remotely identifying PD risk factors and prodromal symptoms in a large cohort of middle-aged and older adults at three European study sites (Barcelona, Spain; Luxembourg, Luxembourg; and Innsbruck, Austria) were analyzed. The dissemination strategies were categorized as digital or traditional. Descriptive statistics were used to summarize the dissemination strategies, geographic reach, linguistic adaptation, survey completion levels, how the participants became aware of the survey and costs associated with the dissemination strategies. </sec> <sec> <title>RESULTS</title> The dissemination strategies in the HeBA study followed a mixed approach. While Barcelona (55.7%) and Luxembourg (53.3%) prioritized digital strategies, in Innsbruck, traditional media slightly predominated (52.2%). Digital advertising strategies were the primary source of recruitment in Barcelona (60.8%), flyers or invitation letters in Luxembourg (41.0%), and radio or television reports in Innsbruck (31.6%). Demographic analysis revealed varied distributions of the sex of participants across centers, while consistently showing that both digital and traditional channels predominantly reached the under-65 age group. The global cost per completed survey was lowest in Barcelona (€4.99), followed by Innsbruck (€9.36) and Luxembourg (€17.80). </sec> <sec> <title>CONCLUSIONS</title> Digital dissemination proved highly effective in Barcelona, while traditional outreach had greater impact in Luxembourg and Innsbruck. Understanding how participants engage with dissemination channels is important for optimizing recruitment strategies. A balanced mix of digital and traditional dissemination methods is necessary to support successful questionnaire completion. Achieving this balance between reach, engagement and costs facilitates effective recruitment in population-based studies on neurodegenerative diseases like Parkinson’s disease, as demonstrated by the HeBA study. </sec>