Abstract 16536: Construction and Validation of a New Termination-of-Resuscitation Rule for Out-of-Hospital Cardiac Arrest in the Japanese Population

BackgroundTermination of resuscitation (TOR) rules for out-of-hospital cardiac arrest (OHCA) have been constructed for better utilization of hospital healthcare resources and increasing the availability of care for other patients.ObjectiveTo validate the TOR-ALS rule in the Japanese population and to establish a new TOR rule for terminating ongoing resuscitation just after hospital arrival.MethodsData from a nationwide database of a prospective population-based cohort using an Utstein-style template for OHCA patients during January 2005 to December 2014 as used for the current analysis. We constructed a new TOR rule consisting of 5 factors (no-witness, no-ROSC, asystole for the initial rhythm, no-defibrillation, age) including the patients during 2005 to 2012 (derivation cohort). Statistical values to predict death and unfavorable neurological outcome(UNO) at one-month were calculated for the TOR-ALS rule (no-witness, no-bystander, no-return of spontaneous circulation (ROSC), no-defibrillation before hospital arrival) and the new rule, respectively. After constructing the new rule, we validated it in a cohort of patients during 2013 to 2014 (validation cohort).ResultsOf the 1,176,363 patients documented for the study period, 906,044 adult patients with OHCA without external causes of arrest were included in the present analysis. In the derivation cohort (n=705,560), values (sensitivity/specificity/PPV/NPV/AUC-ROC) to predict death for each rule were as followed; TOR-ALS rule (32.0%/95.9%/99.4%/5.9%/0.640), new rule (31.9%/98.2%/99.8%/6.0%/0.651). Values to predict UNO were, TOR-ALS rule (31.5%/98.4%/99.87%/3.3%/0.650), new rule (31.4%/99.4%/99.96%/3.3%/0.654). In the validation cohort (n=200,484), values to predict death were, TOR-ALS rule (27.4%/97.3%/99.5%/6.7%/0.623), new rule (33.1%/98.5%/99.7%/7.4%/0.658). Values to predict UNO were, TOR-ALS rule (26.8%/99.0%/99.89%/3.7%/0.629), new rule (32.4%/99.6%/99.97%/4.0%/0.660).ConclusionThe new TOR rule has a higher PPV and specificity to predict unfavorable outcome of OHCA in a Japanese population.