Triaging and referring in adjacent general and emergency departments (the TRIAGE-trial): A process evaluation of medical staff experiences in a nurse-led triage system

•A grounded theory study identified facilitators and inhibitors in the implementation of nurse-led triage.•ED Triage with streaming to GPs lowererd perceived workload for the ED.•An extended triage protocol increased complexity and triage time.•Experience and personal characteristics of ED nurses determined confidence in the protocol.•Communication training and feedback can facilitate the implementation process.