Abstract

Background and Objectives
Recruitment and retention difficulties remain major threats to the success, efficiency, and value of clinical trials, yet robust evidence on how to address these challenges is limited. Studies Within A Trial (SWATs) provide a scalable method for evaluating trial process interventions, but their implementation is often hampered by a lack of accessible, standardised resources. The PRESS (Protocols and Resources for Priority Recruitment and Retention SWATs) project aimed to develop a suite of ready-to-use, evidence-informed materials to support rapid and rigorous evaluation of prioritised recruitment and retention strategies.

Methods
PRESS followed a structured methodological development process informed by existing evidence, stakeholder input, and PPI co-production. We used outputs from previous systematic reviews, PRioRiTy I and II, and the Trial Forge SWAT Network to identify high-priority recruitment and retention questions. Multidisciplinary working groups coveringtrial methodology, statistics, health economics, ethics, accessibility, and PPI independently drafted resources using an iterative consensus-building approach. Drafts were refined through internal review, cross-team consultation, and linguistic/feasibility review by PPI Partners. All outputs were standardised to support reuse across diverse trial contexts.

Results
PRESS delivered a comprehensive, openly accessible SWAT resource pack including a Master SWAT Protocol template; nine randomised recruitment and retention SWAT protocols including two co-produced PPI-focused SWAT protocols; nine ethics templates; two statistical analysis plan templates; funding application guidance; health economics guidance; and accessibility recommendations. These resources collectively support efficient and consistent implementation of high-priority SWATs.

Conclusion
PRESS provides a coherent, evidence-informed infrastructure to support high-priority SWAT evaluations and reduce barriers to their implementation. By enabling trial teams to embed SWATs more easily and consistently, PRESS has the potential to accelerate methodological evidence generation, reduce research waste, and improve participant experience. Broad uptake of PRESS resources may enhance overall trial efficiency and contribute to a stronger evidence base for recruitment and retention strategies.