PRECISely how can PRECIS-2 help design trials to achieve practical answers to “real world” questions? Kirsty Loudon Impact Fellow NMAHP Research Unit   E-mail: Kirsty.loudon@stir.ac.uk Twitter: @KirstyLoudon @PRECIS_2 Skype: Kirsty3

Why? Pragmatic trials – Trials that test if an intervention will work in usual conditions Explanatory trials – Trials that test if an intervention will work in highly controlled, ideal circumstances Continuum not Dichotomy Explanatory and pragmatic attitudes in therapeutical trials (1967). Schwartz D, Lellouch J. Republished in J Clin Epidemiol. 2009;62(5):499-505

PRECIS-2 wheel

How to use PRECIS-2? Why are you doing your trial? Are you taking an explanatory approach to answer the question “Can this intervention work under ideal conditions? Are you taking a pragmatic approach and answer the question ‘Does this intervention work under usual conditions? Consider the trial design choices for each of the PRECIS-2 domains Score 1-5 for these choices and/or mark on the PRECIS wheel Review your choices, reiterate if necessary.

PRECIS-2 key feature Improve applicability of trial results HELP trialists think about consequences of design decisions So trialists consider “how different is the trial…. to usual care”

PRECIS-2 domains 1. Eligibility—To what extent are the participants in the trial similar to those who would receive this intervention if it was part of usual care? 2. Recruitment—How much extra effort is made to recruit participants over and above what would be used in the usual care setting to engage with patients? 3. Setting—How different are the settings of the trial from the usual care setting?

Organisation domain in PRECIS-2 How different are the resources, provider expertise and the organisation of care delivery in the intervention arm of the trial and those available in usual care? For example, score 5 for very pragmatic choice with identical organisation to usual care; score 1 for a very explanatory approaches if the trial increases staff levels, gives additional training, requires more than usual experience or certification and increase resources. Eg ARDSNET

PRECIS-2 domains 5. Flexibility (delivery)—How different is the flexibility in how the intervention is delivered and the flexibility anticipated in usual care? 6. Flexibility (adherence)—How different is the flexibility in how participants are monitored and encouraged to adhere to the intervention from the flexibility anticipated in usual care? 7. Follow-up—How different is the intensity of measurement and follow-up of participants in the trial from the typical follow-up in usual care? 8. Primary outcome—To what extent is the trial’s primary outcome directly relevant to participants? 9. Primary analysis—To what extent are all data included in the analysis of the primary outcome?