Funding for this research was provided by:
Wellcome Trust (110488/Z/15/Z)
Received: 22 October 2018
Accepted: 11 November 2019
First Online: 27 November 2019
Ethics approval and consent to participate
: Ethics approval for this study was given by the University of Lincoln School of Health and Social Care Research Ethics Committee.All participants received a participant information sheet and a consent form prior to taking part and written consent gained.
: Participants were asked to confirm consent for publication as part of the study consent form.
: Quinn declares current research funding from the National Institute for Health Research and British Heart Foundation. The funders played no role in the study design, data collection, analysis, or interpretation, or in writing the manuscript.Siriwardena declares current funding from the National Institute for Health Research to conduct research and trials involving ambulance services. The funders played no role in the study design, data collection, analysis, or interpretation, or in writing the manuscript.