| Description: |
ObjectivesAmbulances offer the first opportunity to evaluate hyperacute stroke treatments. We investigated the conduct of a hyperacute stroke study in the ambulance-based setting with a particular focus on timings and logistics of trial delivery.DesignMulticentre prospective, single-blind, parallel group randomised controlled trial.Setting Eight NHS ambulance services in England and Wales; 54 acute stroke centres. ParticipantsParamedics enrolled 1,149 patients with likely stroke, face, arm speech (2 or 3), within four hours of symptom onset and systolic BP>120mmHg.InterventionsParamedics administered randomly assigned active transdermal glyceryl trinitrate or sham. Primary and Secondary OutcomesModified Rankin scale at day-90. This paper focuses on response time intervals, distances travelled and baseline characteristics of patients, compared between ambulance services.ResultsParamedics enrolled 1,149 patients between September 2015 and May 2018. Final diagnosis: intracerebral haemorrhage 13%, ischaemic stroke 52%, TIA 9%, mimic 26%. Timings (minutes) were (median [25, 75 centile]): onset to emergency call 19 [5, 64]; onset to randomisation 71 [45, 116]; total time at scene 33 [26, 46]; depart scene to hospital 15 [10, 23]; randomisation to hospital 24 [16, 34] and onset to hospital 97 [71, 141]. Ambulances travelled (km) 10 [4, 19] from scene to hospital. Timings and distances differed between ambulance service, e.g. onset to randomisation (fastest 53, slowest 77 minutes; p |