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Table 2 Studies attempting to quantify PRECIS dimensions since 2010

From: How pragmatic or explanatory is the randomized, controlled trial? The application and enhancement of the PRECIS tool to the evaluation of a smoking cessation trial

# Study Author Year Ref. Context of use and development Numeric scale Delphi/iterative process Conclusions Limitations
1 The Pragmatic–Explanatory Continuum Indicator Summary (PRECIS) instrument was useful for refining a randomized trial design: experiences from an investigative team Riddle et al. 2010 [17] ·Prospective use of the tool to modify study design in 3-arm study of pain coping in patients scheduled to have a knee replacement 1-day meeting of 7 authors/investigators: 1) Pre-read Thorpe et al., 20092) Discuss goal of study3) Discuss criteria4) Initial blinded rating5) Ideal blinded rating6) 3rd rating to see if consensus was reached · Yes: 4-cm line to be marked independently on paper in person in 5 min followed by discussion · Scores measured by a ruler Yes · Modification of study· Closer consensus and more explanatory in design · 4-cm scale using VAS; not applicable to online ratings
2 Alternative approaches to tuberculosis treatment evaluation: the role of pragmatic trials Bratton et al. 2011 [18] · Retrospective· 2 reviewers rated 3 published studies on TB treatment and discussed how to rate them on each dimension · No, but modification to the dimensions made (practitioner expertise) combined and a new spoke for blindness inserted · Yes, but not described in detail · Pragmatic trials in TB might lessen time to implementation in real-world settings · No metric at all, simply subjective
3 Pragmatic vs explanatory trials: the Pragmascope tool to help measure differences in protocols of mental health RCTs Tosh et al. 2011 [19] · Adapt (PRECIS) to assist researchers during protocol stage of RCTs in mental health (the Pragmascope tool)· Retrospective· 3 reviewers
· Cochrane Schizophrenia Group Trials Register and Medline (November 2010) for references of RCT protocols. Chose a random sample of 10 protocols dealing with schizophrenia, depression, post-traumatic stress disorders, and psychiatric rehabilitation
· 1 to 5; 0 for missing information· Total score, 0 to 50· 0 to 30, explanatory; 31- 39, intermediate; ≥35, explanatory· However: Figure 1 (see main text) demonstrates an explanatory study investigating whether the experimental intervention will work in ideal circumstances (total score 0–15) and a more pragmatic study focusing mostly on whether, in routine practice, an intervention has a meaningful effect (total score >35)· A total score between 16 and 35 suggests an interim where trial design balances pragmatic and explanatory domains · Not described · Useful tool given high inter-rater reliability · Scoring not clear; neither why the midpoint of 25 was not chosen as a balanced trial· Does the total score perpetuate the dichotomous classification of studies?
4 Applying the PRECIS criteria to describe 3 effectiveness trials of weight loss in obese patients with comorbid conditions. Glasgow et al. 2011 [20] · Practice-based Opportunities for WEight Reduction (POWER) trials (3 studies)· Reduce weight in primary care in those with one CVD risk factor. Studies were ongoing and in the field· 9 reviewers scored each protocol in a 4-step process. 1) Read article and review webinar by Sackett2) Score using 0 to 4 on the dimension· 8 additional ratings; representation of participants and settings, inclusion of cost estimates, reporting on context and level of engagement with the primary care practices · 0 to 4 on the dimension with total composite scores also · Not formally described, but does mention frequent calls to gain consistency in the interpretation of the dimensions · Requires discussion and training to clarify each criteria · ? Rater bias towards pragmatic· Scale difficult to interpret, but need cognitive testing as part of a qualitative study· Hard to find a reliability index
5 Pragmatic vs. explanatory: an adaptation of the PRECIS tool helps to judge the applicability of systematic reviews for daily practice Koppenaal et al. 2011 [21] · Improve lifestyle in general; should be implemented in general practice· Modified the PRECIS tool (called PRECIS Review tool [PR tool]) to grade individual trials and systematic reviews of trials· This should help policy makers, clinicians, researchers, and guideline developers to judge the applicability of individual trials and systematic reviews· 2 systematic reviews · 1 to 5 rating· Individual studies and the review itself were scored· Abandoned VAS with 0 to 10 due to the arbitrary distinctions between consecutive scores· Used a Likert-type scale of 1 to 5, with concurrent %· If 3 dimensions unscorable, a randomized controlled trial was not to be used· 1 to 5 less arbitrary than 0 to 10 for this type of review · 2 independent scores per study and then discussion to reach consensus· If unable, then consultation with third rater ·Useful tool for reviewers and policy makers and trialists· Ability to detect heterogeneity in studies included in systematic reviews · Missing information more likely for a dimension to be rated as pragmatic· Applicability to setting and context needs to considered by policy makers even if a trial is considered pragmatic· Equal weighting for each dimension
  1. RCT: randomized controlled trial.