Infectious Disease · Medical Literature
Effect of Information-Video Presenter Sex on Recruitment
Abstract
This trial within the Danish DAN-RSV adult respiratory syncytial virus vaccine trial assesses whether the sex of the person presenting an informational video for potential trial participants is associated with trial enrollment.
Clinical relevance
This trial-within-a-trial, embedded within the large pragmatic Danish DAN-RSV RSV vaccine study (>130,000 adults aged ≥60 years), addresses a largely unexplored methodological question in clinical trial design: whether the sex of a recruitment video presenter influences enrollment rates in a digitally-recruited population. With remote, video-based informed consent becoming increasingly common in pragmatic trials, understanding factors that drive or impede participation is directly relevant to trial diversity, representativeness, and generalizability. Optimizing recruitment strategies is especially critical in vaccine effectiveness trials where reaching enrollment targets quickly and equitably is essential.
Key findings
NOTE: The full quantitative results of this article were not accessible beyond the abstract; the following findings are based solely on the published abstract and trial context. Specific effect sizes, confidence intervals, p-values, and NNT/NNH for the video presenter sex intervention cannot be reported without access to the full text. 1. The study is a randomized trial-within-a-trial nested within the DAN-RSV pragmatic RSV vaccine trial, which enrolled >130,000 Danish adults aged ≥60 years during the 2024–2025 winter season. 2. The intervention examined was the sex of the presenter in an informational recruitment video shown to potential trial participants prior to enrollment decision. 3. The primary outcome was trial enrollment rate, assessed as a function of presenter sex assignment. 4. The DAN-RSV parent trial used fully digital recruitment via the Danish governmental electronic mail system, making it an ideal setting to test video-based recruitment variables at scale. 5. No specific enrollment rate differences, odds ratios, confidence intervals, or p-values are available from the abstract alone. 6. The trial design allows for a well-powered, internally valid assessment of presenter sex effects given the very large parent trial sample size.
Practice implications
Clinicians and trialists designing pragmatic or digitally-recruited trials should be aware that presentation factors—including the sex of a video presenter—may influence enrollment rates and participant diversity, though the specific direction and magnitude of effect from this study could not be confirmed from the abstract alone. If the study demonstrates a significant effect of presenter sex on enrollment, trialists should consider intentional selection or balanced representation of presenter sex in recruitment materials, particularly for trials targeting populations where sex concordance may affect trust or engagement. Future trial protocols should prospectively embed similar pragmatic sub-studies to systematically evaluate and optimize recruitment methodology.