Measurement and data sources
chest compression
EVENT
The simulation room was equipped with two cameras, which recorded every event in image and sound. The execution of each step of the dispatcher's instructions was measured categorically by analysing the simulation videos. To investigate the impact of the wording of check for breathing instruction the original T-CPR protocol as used by the regional dispatch centre was compared to a modified instruction on assessing breathing. The original check for breathing instruction was used in simulation 1–20 and the modified check for breathing instruction was used in simulation 21–48. In simulations 1–20 (original wording group) the wording from the protocol was: “Is he/she breathing normally? “. In simulation 21–48 (intervention group), check for breathing was specified using the following question: “When you tilt the head backward, does the chest rise and fall?”. No further parts of the protocol were changed. The entire protocol can be viewed in Fig. Telephone-cardiopulmonary resuscitation protocolLaerdal's Resusci Anne QCPR MK II was used as the resuscitation simulator with a wireless connected SimPad® Plus from Laerdal™. The SimPad® Plus assesses compression depth (in mm), chest compression frequency (in bpm) and chest release (0% (no release)—100% (complete release)). The resuscitation data were averaged and processed using MATLAB® R2020b (MathWorks, Natick, USA). Hand position was also evaluated using the videos and was scored as sufficient if the heel of the hand was in a 9 × 9 cm square on the centre of the chest.