Suematsu Y, Zhang B, Kuwano T, et al. - Data from the All-Japan Utstein Registry—a prospective, nationwide, population-based, observational study that was started in January 2005—was assessed by the experts in order to determine the citizen bystander–patient correlation and 1-month outcomes following out-of-hospital cardiac arrest (OHCA) of cardiac origin. A total of 210,642 adults in the registry who experienced OHCA of cardiac origin seen by a citizen bystander between 2005 and 2014 were evaluated. Nearly 65.1% of the citizen bystander-witnessed cases were seen by a family member. However, among patients who survived to 1 month and who had favorable 1-month neurological outcomes, much lower proportions (53.9% and 48.9%, respectively) were witnessed by a family member. Upon controlling for the patient’s age, first recorded rhythm, gender, bystander cardiopulmonary resuscitation, use of a public-access automated external defibrillator, dispatcher instructions, collapse-call time and response time, witnessed by a friend, colleague or passerby was correlated with good 1-month neurological function vs witness by a family member. Hence, in comparison with those in cases witnessed by a friend, colleague or passerby, 1-month survival and favorable 1-month neurological outcome of patients with OHCA of cardiac origin witnessed by a family member were worse, independent of the patient features and the response of emergency medical service.