Moderating effects of out-of-hospital cardiac arrest characteristics on the association between EMS response time and survival. (December 2021)

• Record Type: Journal Article
• Authors: Stoesser, Clara E.; Boutilier, Justin J.; Sun, Christopher L.F.; Brooks, Steven C.; Cheskes, Sheldon; Dainty, Katie N.; Feldman, Michael; Ko, Dennis T.; Lin, Steve; Morrison, Laurie J.; Scales, Damon C.; Chan, Timothy C.Y.
• Is Part Of: Resuscitation. Volume 169(2021)
• Page Start: 31
• Page End: 38
• Publication Date: 2021-12
• Subjects: Out-of-hospital cardiac arrest -- Response time -- Public health -- Emergency medical services; AED Automated external defibrillator -- AUC area under the receiver operating characteristic curve -- CI confidence interval -- CPR cardiopulmonary resuscitation -- EMS emergency medical services -- OHCA out-of-hospital cardiac arrest -- OR odds ratio -- PAD public access defibrillation -- ROC resuscitation outcomes consortium; Resuscitation -- Periodicals; Resuscitation -- Periodicals; Réanimation -- Périodiques; Electronic journals; 616.025
• DOI: 10.1016/j.resuscitation.2021.10.014
• Languages: English
• ISSNs: 0300-9572

Abstract

Abstract: Background: Although several Utstein variables are known to independently improve survival, how they moderate the effect of emergency medical service (EMS) response times on survival is unknown. Objectives: To quantify how public location, witnessed status, bystander CPR, and bystander AED shock individually and jointly moderate the effect of EMS response time delays on OHCA survival. Methods: This retrospective cohort study was a secondary analysis of the Resuscitation Outcomes Consortium Epistry-Cardiac Arrest database (December 2005 to June 2015). We included all adult, non-traumatic, non-EMS witnessed, and EMS-treated OHCAs from eleven sites across the US and Canada. We trained a logistic regression model with standard Utstein control variables and interaction terms between EMS response time and the four aforementioned OHCA characteristics. Results: 102, 216 patients were included. Three of the four characteristics – witnessed OHCAs (OR = 0.962), bystander CPR (OR = 0.968) and public location (OR = 0.980) – increased the negative effect of a one-minute delay on the odds of survival. In contrast, a bystander AED shock decreased the negative effect of a one-minute response time delay on the odds of survival (OR = 1.064). The magnitude of the effect of a one-minute delay in EMS response time on the odds of survival ranged from 1.3% to 9.8% (average: 5.3%), depending on the underlying OHCA characteristics. Conclusions: Delays in EMS response time had the largest reduction in survival odds for OHCAs that did not receive a bystander AED shock but were witnessed, occurred in public, and/or received bystander CPR. A bystander AED shock appears to be protective against a delay in EMS response time.