title: Termination-of-resuscitation rule for emergency department physicians treating out-of-hospital cardiac arrest patients: an observational cohort study.
abstract: BACKGROUND
  The 2010 cardiopulmonary resuscitation guidelines recommend emergency medical services (EMS) personnel consider prehospital termination-of-resuscitation (TOR) rules for out-of-hospital cardiac arrest (OHCA) following basic life support and/or advanced life support efforts in the field. However, the rate of implementation of international TOR rules is still low. Here, we aimed to develop and validate a new TOR rule for emergency department physicians to replace the international TOR rules for EMS personnel in the field. This rule aims to guide physicians in deciding whether to withhold further resuscitation attempts or terminate on-going resuscitation immediately after patient arrival.
  
  
  METHODS
  We analyzed data prospectively collected in a nationwide Utstein-style Japanese database between 2005 and 2009, from 495,607 adult patients with OHCA. Patients were divided into development (n = 390,577) and validation (n = 105,030) groups. The main outcome measures were specificity, positive predictive value (PPV), and area under the receiver operating characteristic (ROC) curve for the newly developed TOR rule.
  
  
  RESULTS
  We developed a new TOR rule that includes 3 criteria based on the results of multivariate logistic regression analysis for predicting a 1-month death after OHCA: no prehospital return of spontaneous circulation (adjusted odds ratio [OR], 25.8; 95% confidence interval [CI], 24.7-26.9), unshockable initial rhythm (adjusted OR, 2.76; 95% CI, 2.54-3.01), and unwitnessed by bystanders (adjusted OR, 2.18; 95% CI, 2.09-2.28). The specificity, PPV, and area under the ROC curve for this new TOR rule for predicting 1-month death in the validation group were 0.903 (95% CI, 0.894-0.911), 0.993 (95% CI, 0.992-0.993), and 0.874 (95% CI, 0.872-0.876), respectively.
  
  
  CONCLUSIONS
  We developed and validated a new TOR rule for emergency department physicians consisting of 3 prehospital variables (no prehospital ROSC, unshockable initial rhythm, and unwitnessed by bystanders) that is a >99% predictor of very poor outcome. However, the implementation of this new rule in other countries or EMS systems requires further validation studies.
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Goto
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Maeda
authors.forename: Yumiko Nakatsu
authors.initials: YN
authors.lastname: Goto
mesh_terms: D000328:Adult; D000368:Aged; D016887:Cardiopulmonary Resuscitation / Q000592:standards*; D003661:Decision Support Techniques; D004636:Emergency Service, Hospital / Q000592:standards*; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008020:Life Support Care / Q000592:standards*; D008297:Male; D008875:Middle Aged; D058687:Out-of-Hospital Cardiac Arrest / Q000401:mortality / Q000628:therapy*; D017410:Practice Guidelines as Topic; D011237:Predictive Value of Tests; D011446:Prospective Studies; D016414:Resuscitation Orders; D012680:Sensitivity and Specificity; D015996:Survival Rate