Table 1

Feasibility success metrics providing support for a future trial

Green light (proceed with minor changes)Amber light (proceed with significant modifications)Red light (do not proceed)
Recruitment50 or more patients recruited25–49 patients recruited24 or fewer patients recruited
Treatment fidelityAt least 60% of randomised participants receive allocated treatmentsAt least 40% of randomised participants receive allocated treatmentsLess than 40% of randomised participants receive allocated treatments
Rate of assessment attrition at 3 and 6 monthsLess than 30% at 3 and 6 monthsLess than 60% at 3 and 6 months61% or more at 3 and 6 months
Qualitative dataPositive opinions and/or feasibility recommendations to improve the follow-on trial. We will hold an end of study workshop with all coinvestigators, site PIs, patient/carer representatives and other stakeholders to present the outcomes and discuss approaches to address issues noted as green or amber and reasons for red lights.