Changes in demographic factors and mortality after out-of-hospital cardiac arrest in Sweden

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<0.0001) with an increase in crew-witnessed cases and a decrease in non-witnessed cases. There was a decrease in cases of a cardiac etiology from 75 to 61% (P<0.0001) and a decrease in the percentage found in ventricular fibrillation from 36 to 25% (P<0.0001). When crew-witnessed cases were excluded the proportion receiving bystander cardiopulmonary resuscitation (CPR) increased from 30 to 42% (P