Table 1.

Pragmatic design features of the REGAIN trial

PRECIS domain(s)	Assessment
1. Participant eligibility criteria	Ghis study will enrol a broad group of hip fracture patients without contraindications to regional or general anaesthesia who were ambulatory prior to fracture. Patients will be enrolled from a group of diverse academic and community sites. While the results may not be generalisable to some groups of patients, such as those who were not ambulatory before fracture, the broad eligibility criteria make the study highly pragmatic in this domain.
2 and 3. Experimental and comparison interventions—flexibility	Treating physicians will receive brief, simple and highly flexible care protocols for patients randomised to receive spinal anaesthesia; these protocols will state explicitly that co-interventions will are permitted based on clinical judgement. The study is maximally pragmatic in this domain.
4 and 5. Experimental and comparison interventions—practitioner expertise	Study protocols will be administered by clinical anaesthesia staff without requirements for additional training in specific anaesthesia techniques or advanced expertise. The study is maximally pragmatic in this domain.
6. Follow-up intensity	In-hospital outcomes will be assessed by 3 brief assessments over the first 3 postoperative days and by chart review at discharge. Blinding will not be required for in-hospital assessments to maximise study feasibility across a range of hospital settings. Postdischarge follow-up will occur via brief minute phone interviews at 60, 180 and 365 days by assessors who are blinded to treatment assignment. Survival will be assessed by searches of vital records files. The study is highly pragmatic in this domain.
7. Primary trial outcome	The primary outcome (death or inability to walk across a room at 2 months) is simple and pragmatic; secondary outcomes are also pragmatic end points, including overall disability, return to prefracture residence and all-cause mortality.
8. Participant compliance with prescribed intervention	Randomisation to regional vs general anaesthesia will be clearly stated in the study consent form. Since patients who do not want either regional or general anaesthesia will be unlikely to enrol in the trial, the study is more explanatory than pragmatic in this domain.
9. Practitioner adherence to study protocol	Practitioner adherence to treatment assignment will be monitored and efforts will be made to limit deviations from assigned treatments; the study is more explanatory than pragmatic in this regard.
10. Analysis of primary outcome	All randomised patients will be included in the primary analysis; additional analyses will be adjusted for compliance with the study protocol. A priori subgroups will be examined; the proposal is moderately pragmatic in this regard.

Domains are adapted from the Pragmatic-Explanatory Continuum Indicator Summary (PRECIS) framework of Thorpe et al.¹⁹ The 10 listed domains for the REGAIN trial are described and characterised in relation to design aspects common to pragmatic (effectiveness) versus explanatory (efficacy) trials.