title: Trends in survival among elderly patients with out-of-hospital cardiac arrest: a prospective, population-based observation from 1999 to 2011 in Osaka.
abstract: BACKGROUND
  Little is known about the improvement in out-of-hospital cardiac arrest (OHCA) survival among elderly patients. The aim of this study was to evaluate the trends in the survival after bystander-witnessed OHCA of cardiac origin in this age group.
  
  
  METHODS
  This prospective, population-based, observation of the whole population of Osaka, Japan included consecutive OHCA patients aged ≥65 years with emergency responder resuscitation attempts from January 1999 to December 2011. The primary outcome measure was one-month survival with neurologically favorable outcome, and the trends in the outcome from OHCA were evaluated by location. Multiple logistic regression analysis was used to assess factors that were potentially associated with neurologically favorable outcome.
  
  
  RESULTS
  During the study period, a total of 10,876 bystander-witnessed OHCA of cardiac origin were eligible for our analyses. In whole arrests, the proportion of one-month survival with neurologically favorable outcome improved from 1.4% in 1999 to 4.8% in 2011 (P for trend <0.001). The proportion of neurologically favorable outcome in homes and public places improved from 0.7% in 1999 to 3.2% in 2011 (P for trend <0.001) and from 4.2% in 1999 to 20.9% in 2011 (P for trend <0.001), respectively, whereas, in nursing homes, the proportion of neurologically favorable outcome did not improve. In a multivariate analysis, bystander-initiated cardiopulmonary resuscitation and emergency response time were significant predictors for neurologically favorable outcome.
  
  
  CONCLUSIONS
  In this population, survival from OHCA among elderly patients significantly improved during the study period, but the trends differed by the OHCA location.
authors.affiliation: Division of Environmental Medicine and Population Sciences, Department of Social and Environmental Medicine, Graduate School of Medicine, Osaka University, 2-2 Ymamada-oka, Suita 565-0871, Osaka, Japan. Electronic address: lucky_unatan@yahoo.co.jp.
authors.forename: Tetsuhisa
authors.initials: T
authors.lastname: Kitamura
authors.affiliation: Senri Critical Care Medical Center, Osaka Saiseikai Senri Hospital, 1-1-6 Tsukumodai, Suita 565-0862, Osaka, Japan.
authors.forename: Sachiko
authors.initials: S
authors.lastname: Morita
authors.affiliation: Division Department of Public Health, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan.
authors.forename: Kosuke
authors.initials: K
authors.lastname: Kiyohara
authors.affiliation: Department of Critical Care Nursing, Graduate School of Medicine and School of Health Sciences, Kyoto University, 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan.
authors.forename: Chika
authors.initials: C
authors.lastname: Nishiyama
authors.affiliation: Department of Traumatology and Acute Critical Medicine, Osaka University Graduate School of Medicine, 2-15 Yamada-oka, Suita 565-0871, Osaka, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Kajino
authors.affiliation: Department of Traumatology and Acute Critical Medicine, Osaka University Graduate School of Medicine, 2-15 Yamada-oka, Suita 565-0871, Osaka, Japan.
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Sakai
authors.affiliation: Department of Acute Medicine, Kinki University Faculty of Medicine, 377-2 Ohno-Higashi Osaka-Sayama, Osaka 589-8511, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Nishiuchi
authors.affiliation: Senri Critical Care Medical Center, Osaka Saiseikai Senri Hospital, 1-1-6 Tsukumodai, Suita 565-0862, Osaka, Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Hayashi
authors.affiliation: Department of Traumatology and Acute Critical Medicine, Osaka University Graduate School of Medicine, 2-15 Yamada-oka, Suita 565-0871, Osaka, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Shimazu
authors.affiliation: Kyoto University Health Services, Yoshida-Honmachi, Sakyo-ku, Kyoto 606-8501, Japan.
authors.forename: Taku
authors.initials: T
authors.lastname: Iwami
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016887:Cardiopulmonary Resuscitation / Q000379:methods / Q000401:mortality*; D002423:Cause of Death; D004632:Emergency Medical Services / Q000379:methods / Q000706:statistics & numerical data*; D005260:Female; D015577:Geriatric Assessment; D006801:Humans; D007564:Japan; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D058687:Out-of-Hospital Cardiac Arrest / Q000401:mortality* / Q000628:therapy*; D011446:Prospective Studies; D012042:Registries; D012189:Retrospective Studies; D018570:Risk Assessment; D016019:Survival Analysis; D016896:Treatment Outcome
keywords: Cardiac arrest; Cardiopulmonary resuscitation; Elderly; Epidemiology