Study design
We conducted a parallel randomized pilot study to compare DACPR quality of participants from two CPR trainings: a standard CPR training and a brief DACPR training in addition to a standard training. We recruited non-health care providers with no CPR training experience within one year prior to this study.
CPR trainings
The training sessions were held at Nara Medical University. The first cohort were given a standard CPR training including automated external defibrillator (AED) usage (Standard Group). The second cohort were given a standard CPR with a 10-minute DACPR training (DACPR Group). In the DACPR Group, participants learned DACPR through caller-dispatcher role playing with CPR manikins and a template for CPR instruction at the end of the training. Both training courses were 90-minute in length. Participants were assigned randomly one of the CPR trainings scheduled by study investigators. All the participants were blinded to their allocations until the end of the training. Six months after the trainings, all participants were invited to the DACPR simulation via phone.
DACPR Simulation
We conducted a simulation of DACPR six months after the trainings. In this simulation, participants performed a single rescuer scenario in a small room at Nara Medical University. In this room, there was a manikin (Laerdal Resusci Anne manikin with Skill Reporting System) on the hard surface floor and a cordless extension phone on a small table. Neither an AED nor other rescuers were available in this simulation. After being given a list of simple instructions (Appendix 1), participants entered the room and perform CPR under instruction by dispatchers. Nine dispatchers with at least one year of experience took part in this simulation. All dispatchers were blinded to participants’ allocations between the two cohorts. Dispatchers were instructed not to ask the address, not to instruct the participant to perform rescue breathing, and strictly instructed to tell the participant to activate the speaker phone function and continue chest compression instruction for 2 minutes (Appendix 2). Dispatchers provided instruction following the standard DACPR instruction provided by Japanese Fire and Disaster Management Agency19. Each participant performed two-minute DACPR simulation and was offered a $10 value gift card as an incentive for the simulation.
Data collection and outcome
Data for chest compression performance (mean depth [mm], mean rate [cpm: compression per minute], hand position [%]) were collected through the Laerdal Skill Reporting System®. Data regarding time intervals of call to identification of the need for CPR, start of CPR instruction, and start of chest compression were recorded by video cameras (SONY HDR - AS200V). The outcome of this study was the quality of DACPR: time interval between call receipt and the first chest compression, and the quality of chest compressions.
For characteristics of participants, only approximate age such as 20s or 30s, and gender were obtained. In order to collect enough participants, data regarding exact age, height, weight, and education levels could not be obtained.
Statistics
Since this study was a pilot study, the sample size was set to about 30 in each group with reference to the previous studies8, 12-16.
Continuous variables were described as median and interquartile range (IQR) and categorical variables were described as number (percentages). We used Mann-Whitney U test for continuous variables and chi-square test for categorical variables. Two-tailed p values less than 0.05 were considered as significant. Data analysis was done by SPSS ver. 22.0 (SPSS inc., Chicago, IL. USA).