Describe and apply the PRECIS-2 domains of eligibility, recruitment, settings and organization, as well as the unique characteristics of study population and setting as applied to pragmatic trials.
The Study populations domains are concerned with the questions of “Who is selected to participate in the study?” (Eligibility) and “How participants are recruited into the study?” (Recruitment). In the context of PRECIS-2, “participants" include patients or other individual recipients of an intervention, and/or providers of the intervention. This may include individual participants and/or one or more levels of clusters. For example, in a trial of a continuing education intervention, participants may be health professionals and trained instructors and the trial may be randomized into clusters at the level of the instructor.
Who is selected to participate? - to what extent are the participants in the trial similar to those who would receive this intervention if it was part of usual care?
How are participants recruited? - how much extra effort is made to recruit participants over and above what that would be used in the usual care setting to engage with patients?
To assess the Eligibility domain, we want to evaluate to what extent are the participants in the trial similar to those who would receive this intervention if it was part of usual care.
Explanatory studies tend to have more exclusion criteria than pragmatic ones. Typical reasons for exclusion include:
(1) excluding participants not known/shown to be highly compliant to the interventions under study;
(2) excluding participants not known/shown to be at high risk for the primary trial outcome
(3) excluding participants not expected to be highly responsive to the experimental intervention. The goal of these exclusions is typically to exclude participants who are less likely to respond to the intervention (Loudon, 2015).
The Settings domains are concerned with the questions of “Where is the study being done?” (Setting) and “What expertise and resources are needed to deliver the intervention? (Organization).
Where is the trial being done? - how different is the setting of the trial and the usual care setting?
What expertise and resources are needed? - how different are the resources, provider expertise and the organization of care delivery in the intervention arm of the trial and those available in usual care?
The Setting domain in PRECIS-2 assesses how different is the setting of the study from the usual care setting. Pragmatic trials encourage the selection of multiple, diverse settings in which the intervention would be delivered. More explanatory trials would be characterized by fewer or a single source for the participants (Loudon, 2015).
The Organization domain explores the difference between the resources, provider expertise and the organization of care delivery in the intervention arm of the study and those available in usual care. Increased resource needs, specialized provider expertise and deviance from usual care delivery processes pushes the study to the more explanatory end of the continuum. For example providers delivering the intervention can be restricted to ones with
(1) some defined experience in working with the subjects like the ones to be enrolled in the study;
(2) specialty certification relevant to the given intervention;
(3) experience with the actual intervention (Loudon, 2015).
Krist and colleagues in their pragmatic study of the implementation of the My Own Health Report (MOHR) identified 18 sites to participate.
Each collaborating research team identified one or two pairs of primary care practices within their network that were similar with respect to practice type (e.g., FQHC or PBRN, family practice or internal medicine), practice ownership, geographic region, EHR infrastructure, and patient population served.
Practice pairs were purposefully selected to represent the diversity of primary care settings and populations to ensure greater generalizability of results.
Krist et al, Designing a valid randomized pragmatic primary care implementation trial: the my own health report (MOHR) project. Implement Sci. 2013; 8: 73.
Identical to those in usual care.
Limits the delivery of the intervention to providers with specialized training/expertise, would require additional resources (e.g., increased staff time), and require deviation from /additional steps to the usual care process.
diverse populations from multiple, heterogenous settings.
Study Population: Eligibility and Recruitment (who is selected and why)
Setting: Settings and organization (where the trial is done and what expertise and resources are needed)
The MOHR study shows how a participatory design can be used to promote the consistent collection and use of patient-reported health behavior and psychosocial assessments in a broad range of primary care settings. While pragmatic in nature, the study design will allow valid comparisons to answer the posed research question, and findings will be broadly generalizable to a range of primary care settings. Per the pragmatic explanatory continuum indicator summary (PRECIS) framework, the study design is substantially more pragmatic than other published trials. The methods and findings should be of interest to researchers, practitioners, and policy makers attempting to make healthcare more patient-centered and relevant.
Randomized trials have been broadly categorized as either having a pragmatic or explanatory attitude. Pragmatic trials seek to answer the question, ‘‘Does this intervention work under usual conditions?,’’ whereas explanatory trials are focused on the question, ‘‘Can this intervention work under ideal conditions?’’ Design decisions make a trial more (or less) pragmatic or explanatory, but no tool currently exists to help researchers make the best decisions possible in accordance with their trial’s primary goal. During the course of two international meetings, participants with experience in clinical care, research commissioning, health care financing, trial methodology, and reporting defined and refined aspects of trial design that distinguish pragmatic attitudes from explanatory
PRECIS is a tool to help trialists make design decisions consistent with the intended purpose of their trial. This paper gives guidance on how to use an improved, validated version, PRECIS-2, which has been developed with the help of over 80 international trialists, clinicians, and policymakers. Keeping the original simple wheel format, PRECIS-2 has nine domains—eligibility criteria, recruitment, setting, organisation, flexibility (delivery), flexibility (adherence), follow-up, primary outcome, and primary analysis—scored from 1 (very explanatory) to 5 (very pragmatic) to facilitate domain discussion and consensus. It is hoped PRECIS-2 will be valuable in supporting the explicit matching of design decisions to how the trial results are intended to be used