Designing Fit-for-Purpose Trials with PRECIS-2

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.

PRECIS-2 Wheel
PRECIS-2 Wheel*

*Kirsty Loudon et al. BMJ 2015;350:bmj.h2147. Copyright 2015 by British Medical Journal Publishing Group. Used by permission.

See the PRECIS-2 introductory video (YouTube) and below links for detailed user information.

Health Informatics Centre website
PRECIS-2 Toolkit
Wheel examples