Few clinical trials are entirely explanatory (done in an idealized setting) or entirely pragmatic (done in a usual-care setting); rather, trials are situated somewhere along a continuum of applicability. Pragmatic clinical trials are trials designed with pragmatic qualities and are intended to inform decision makers, including patients, clinicians, administrators, and policymakers, about the relative benefits, burdens, and risks of a health intervention.
To help trialists assess how closely their trial’s design matches its intended purpose, a group of trialists and methodologists developed a design tool, the Pragmatic–Explanatory Continuum Indicator Summary, or PRECIS. Originally implemented in 2008, the wheel-shaped indicator tool recently underwent a revision, leading to PRECIS-2. The revised, validated tool guides trialists to prospectively consider the design of their trial along 9 domains: eligibility criteria, recruitment, setting, organization, flexibility (delivery), flexibility (adherence), follow-up, primary outcome, and primary analysis.
- Original Article: Loudon et al., 2015 – Loudon Kirsty, Treweek Shaun, Sullivan Frank, Donnan Peter, Thorpe Kevin E, Zwarenstein Merrick et al. The PRECIS-2 tool: designing trials that are fit for purpose BMJ 2015;350:h2147
- PRECIS-2 Toolkit