BackgroundAccording to the theory of planned behaviour, the probability of executing an action is strongly linked to the intention of performing it. The aim of this study was to measure the variation over time of the three dimensions of the intention to perform resuscitation, i.e. attitude, subjective normative beliefs, and control beliefs.MethodsThe two largest companies delivering first aid courses in the region of Geneva, Switzerland, sent invitation e-mails on our behalf to people who had followed a first aid course in the last five years. Participants were asked to answer a set of 17 psychometric questions designed to assess each dimension of the intention to perform resuscitation. The primary outcome was the change in each dimension at 6 months. Secondary outcomes were the change in each dimension at one and two years and change in each individual question at 6 months, one year and two years.ResultsOut of 270 completed surveys, 204 were analysed. Control beliefs was the only dimension that displayed a significant change at 6 months (p < 0.001). Participants who had followed their last BLS course more than 6 months ago were however more prone to diffusion of responsibility, a key element of subjective normative beliefs (p = 0.001). Fear of legal action was higher in participants who had followed their last BLS course more than 2 years ago (p = 0.040).ConclusionsControl belief, a dimension of the intention to perform resuscitation, rapidly decreases after the last first aid course.