Regional Variation in Out-of-Hospital Cardiac Arrest Survival in the United States

• Authors: Saket Girotra, University of Iowa; Sean van Diepen, University of Alberta; Brahmajee K Nallamothu, University of Michigan; Margaret Carrel, University of Iowa; Kimberly Vellano, Emory University; Monique L Anderson, Duke Clinical Research Institute; Bryan McNally, Emory University; Benjamin Abella, University of Pennsylvania; Comilla Sasson, University of Colorado; Paul S Chan, St Lukes Mid America Heart Institute
• Journal Title: Circulation
• Volume: Volume 133, Number 22
• Publisher: Lippincott Williams & Wilkins | 2016-05-31, Pages 2159-+
• Type of Work: Article | Post-print: After Peer Review
• Publisher DOI: http://doi.org/10.1161/CIRCULATIONAHA.115.018175
• Subjects: Health Sciences, General
• Keywords: Science & Technology; Life Sciences & Biomedicine; Cardiac & Cardiovascular Systems; Peripheral Vascular Disease; Cardiovascular System & Cardiology; cardiopulmonary resuscitation; heart arrest; AMERICAN-HEART-ASSOCIATION; EUROPEAN-RESUSCITATION-COUNCIL; CARDIOPULMONARY-RESUSCITATION; STROKE-FOUNDATION; TASK-FORCE; HEALTH; DEFIBRILLATION; IMPLEMENTATION; PROFESSIONALS; OUTCOMES

Abstract

Background - Although previous studies have shown marked variation in out-of-hospital cardiac arrest survival across US regions, factors underlying this survival variation remain incompletely explained. Methods and Results - Using data from the Cardiac Arrest Registry to Enhance Survival, we identified 96 662 adult patients with out-of-hospital cardiac arrest in 132 US counties. We used hierarchical regression models to examine county-level variation in rates of survival and survival with functional recovery (defined as Cerebral Performance Category score of 1 or 2) and examined the contribution of demographics, cardiac arrest characteristics, bystander cardiopulmonary resuscitation, automated external defibrillator use, and county-level sociodemographic factors in survival variation across counties. A total of 9317 (9.6%) patients survived to discharge, and 7176 (7.4%) achieved functional recovery. At a county level, there was marked variation in rates of survival to discharge (range, 3.4%-22.0%; median odds ratio, 1.40; 95% confidence interval, 1.32-1.46) and survival with functional recovery (range, 0.8%-21.0%; median odds ratio, 1.53; 95% confidence interval, 1.43-1.62). County-level rates of bystander cardiopulmonary resuscitation and automated external defibrillator use were positively correlated with both outcomes (P<0.0001 for all). Patient demographic and cardiac arrest characteristics explained 4.8% and 27.7% of the county-level variation in survival, respectively. Additional adjustment of bystander cardiopulmonary resuscitation and automated external defibrillator explained 41% of the survival variation, and this increased to 50.4% after adjustment of county-level sociodemographic factors. Similar findings were noted in analyses of survival with functional recovery. Conclusions - Although out-of-hospital cardiac arrest survival varies significantly across US counties, a substantial proportion of the variation is attributable to differences in bystander response across communities.