Participants were 45 first-year medical students randomly assigned to cardiopulmonary resuscitation (CPR) self-training using either a video-based presentation or a serious game developed in a 3D learning environment for up to 20 min. Each participant was evaluated on a written, multiple-choice test (theoretical test) and then on a scenario of cardiac arrest (practical test) before and after exposure to the self-learning methods.

A prospective, simulation-based, randomised controlled trial was conducted. Participants were randomised to the video group watched a video-recorded lecture on the management of adult cardiac arrest, while participants randomised to the game group played a serious game on the same topic.

The video was developed based on a previously recorded Keynote presentation (version 6.6.2, Apple Inc.) with the addition of voice-over narration of the events. The video was edited to contain the same information as provided in the serious game. The learning environment simulated an urban public space where the player should identify a victim of cardiac arrest and perform CPR manoeuvres. The game was designed to be a CPR self-learning tool for both health professionals and the lay public. The game involved only one rescuer without access to a portable defibrillator. During the game, the player should identify the victim, diagnose cardiac arrest correctly and initiate CPR as early as possible. The actions of the player were guided throughout the game by step-by-step instructions that should be followed to save the victim's life and to score on the game. Whenever the manoeuvres were not performed correctly, the victim died and the game automatically restarted from the beginning.

After exposure to the self-learning methods, participants were reassessed individually for their theoretical knowledge on a written, 10-question, multiple-choice test (theoretical post-test) and for their practical performance by three examiners, blinded to group assignment, who independently rated the participants' actions on a 10-min simulated scenario of cardiac arrest using a CPR training manikin (practical post-test).

Simulated scenario The same simulated scenario was used for pre-exposure and post-exposure practical evaluation. When the student entered the simulation room, a manikin was lying on the floor, simulating a person lying on the street, unconscious, not responding to stimulation and with no respiratory effort or pulse. The student was alone without access to medical equipment such as a defibrillator. Participants were expected to recognise the cardiac arrest, call the emergency services, and initiate chest compressions and ventilations as soon as possible for at least two cycles. A 10-min time limit was set for each simulation session.

Inclusion Criteria:

• Being a medical student;
• Voluntary participation;
• No previous participation in CPR training.

Exclusion Criteria:

• Previous participation in CPR training.
• Refusal to participate.
• Not being enrolled in medical school.

Single (outcomes assessor)