OBJECTIVE: To describe changes between 1992 and 2003 in age, sex, factors at resuscitation and survival among patients suffering from out-of-hospital cardiac arrest in Sweden. METHODS: This was a prospective observational study including various ambulance organizations in Sweden. Patients suffering from out-of-hospital cardiac arrest between 1992 and 2003 included in the Swedish Cardiac Arrest Registry were followed for survival to 1 month. RESULTS: In all 19 791 cases took part in the survey. There was a slight increase in mean age from 68 to 70 years (P = 0.025) and an increase of females from 29 to 32% (P = 0.0001). There was a change in witnessed status (P