In a long-term study of out-of-hospital cardiac arrest in Denmark, bystander cardiopulmonary resuscitation (CPR) or defibrillation was associated with lower risks of brain damage or admission to a nursing home compared with no bystander resuscitation. The investigators studied 2,855 patients who survived for >30 days after an out-of-hospital cardiac arrest between 2001 and 2012. Overall, 10.5% had brain damage or were admitted to a nursing home, and 9.7% died during follow-up (1 year). Among the 2,084 patients who had a cardiac arrest not witnessed by emergency medical services personnel, the rates of bystander CPR and defibrillation both increased significantly during the study period. In adjusted analyses, the risk of brain damage or nursing-home admission was significantly reduced by either bystander CPR (HR 0.62) or bystander defibrillation (HR 0.45) compared with no bystander resuscitation. Furthermore, all-cause mortality was also reduced by bystander CPR (HR 0.70) or defibrillation (HR 0.22).