Table 1. Search Strings.

‘citizen rescue*’ OR ‘citizen responder*’ OR ‘community rescue*’ OR ‘community responder*’ OR ‘emergency responder*’ OR ‘first person on scene’ OR ‘first responder*’ OR ‘lay emergency medical technician*’ OR ‘lay rescue*’ OR ‘lay responder*’ OR ‘lay-person emergency medical technician*’ OR ‘lay-person rescue*’ OR ‘lay-person responder*’ OR ‘layperson emergency medical technician*’ OR ‘layperson rescue*’ OR ‘layperson responder*’ OR ‘voluntary emergency medical technician*’ OR ‘voluntary rescue*’ OR ‘voluntary responder*’ OR ‘volunteer emergency medical technician*’ OR ‘volunteer rescue*’ OR ‘volunteer responder*’

AND

‘pre-hospital medical emergenc*’ OR ‘prehospital medical emergenc*’ OR ‘prehospital emergenc*’ OR ‘pre-hospital emergenc*’ OR ‘out of hospital medical emergenc*’ OR ‘out of hospital emergenc*’ OR ‘out of hospital cardiac arrest*’