title: Association between resuscitation time interval at the scene and neurological outcome after out-of-hospital cardiac arrest in two Asian cities.
abstract: OBJECTIVE
  It is unclear whether the scene time interval (STI) for cardiopulmonary resuscitation (CPR) is associated with outcomes of out-of-hospital cardiac arrest (OHCA) or not. The present study aimed to determine the association between STI and neurological outcome after OHCA using two large population-based cohorts covering two metropolitan cities in Asia.
  
  
  METHODS
  A retrospective analysis based on two large population-based cohorts from Seoul (2008-2010) and Osaka (2007-2009) was performed for witnessed adult OHCA with presumed cardiac aetiology. The STI, defined as time from wheel arrival at the scene to departure to hospital, was categorised as short (<8min), intermediate (from 8 to <16min) and long (16min or longer) STI on the basis of sensitivity analysis. The primary outcome was good neurological outcome (cerebral performance category 1 or 2). Adjusted odds ratios (AORs) with 95% confidence intervals (CIs) were calculated to determine the association between STIs and outcomes in comparison to the short STI group adjusting for potential risk factors and interaction products.
  
  
  RESULTS
  A total of 7757 patients, 3594 from Seoul and 4163 from Osaka, were finally analysed. There were significant differences among the STI groups for most potential risk variables. Survival to admission was higher in the intermediate STI group (35.7%) than in the short (31.8%) or long STI group (32.6%) (p=0.004). Survival to discharge was not different among groups, at 13.7%, 13.1% and 11.5%, respectively (p=0.094). The intermediate STI group had a significantly better neurological outcome compared with the short STI group (7.7% vs. 4.6%; AOR=1.32; 95% CI, 1.03-1.71), while the long STI (6.6%) did not.
  
  
  CONCLUSIONS
  Data from two metropolitan cities demonstrated a positive association between intermediate STI from 8 to 16min and good neurological outcome after OHCA.
authors.affiliation: Department of Emergency Medicine, Seoul National University College of Medicine, 101 Daehak-Ro, Jongno-Gu, Seoul 110-744, South Korea.
authors.forename: Sang Do
authors.initials: SD
authors.lastname: Shin
authors.affiliation: Division of Environmental Medicine and Population Sciences, Department of Social and Environmental Medicine, Graduate School of Medicine, Osaka University, 2-5 Yamada-oka, Suita, Osaka 565-0871, Japan.
authors.forename: Tetsuhisa
authors.initials: T
authors.lastname: Kitamura
authors.affiliation: Department of Social Medicine, Inha University, Shinheun-Dong 3 Ga, Jung-Gu, Incheon 400-712, South Korea.
authors.forename: Seung Sik
authors.initials: SS
authors.lastname: Hwang
authors.affiliation: Department of Traumatology and Acute Critical Medicine, Graduate School of Medicine, Osaka University, 2-5 Yamada-oka, Suita, Osaka 565-0871, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Kajino
authors.affiliation: Department of Emergency Medicine, Seoul National University Hospital, 101 Daehak-Ro, Jongno-Gu, Seoul 110-744, South Korea.
authors.forename: Kyoung Jun
authors.initials: KJ
authors.lastname: Song
authors.affiliation: Department of Preventive Medicine, School of Public Health, Seoul National University, 1 Kwanak-Ro, Kwanak-Gu, Seoul 151-741, South Korea.
authors.forename: Young Sun
authors.initials: YS
authors.lastname: Ro
authors.affiliation: Department of Critical Care & Emergency Medicine, Graduate School of Medicine, Osaka City University, 1-5-17 Asahimachi, Abeno-ku, Osaka 545-8585, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Nishiuchi
authors.affiliation: Kyoto University Health Service, Yoshida Honmachi, Sakyo-ku, Kyoto 606-8501, Japan. Electronic address: iwamit@e-mail.jp.
authors.forename: Taku
authors.initials: T
authors.lastname: Iwami
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001925:Brain Damage, Chronic / Q000453:epidemiology; D016887:Cardiopulmonary Resuscitation; D004632:Emergency Medical Services / Q000458:organization & administration*; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D058687:Out-of-Hospital Cardiac Arrest / Q000453:epidemiology / Q000628:therapy*; D056910:Republic of Korea / Q000453:epidemiology; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate; D013997:Time Factors; D016896:Treatment Outcome
keywords: Ambulance; Cardiopulmonary resuscitation; Emergency medical service system; Out-of-hospital cardiac arrest; Scene time interval