Clinical paperIncreasing hospital volume is not associated with improved survival in out of hospital cardiac arrest of cardiac etiology☆,☆☆
Introduction
Out-of-hospital cardiac arrest (OHCA) is a major public health problem with an overall mortality of approximately 90% across North America.1 Although prehospital interventions remain an important cornerstone of resuscitation, growing evidence indicates the implementation of specialized post-arrest care can positively affect outcome. In-hospital treatments such as therapeutic hypothermia and early cardiac catheterization provide opportunities to meaningfully improve survival.2, 3, 4
The impact of post-arrest care provides a rationale for the development of cardiac “resuscitation centers”, modeled after trauma centers in the United States (US).5, 6, 7 Some states such as Arizona and Minnesota, have either implemented or are planning to implement such systems of care. These efforts have been complemented by scientific consensus recommendations designed to inform and support the development of resuscitation centers.7 Higher patient volume is associated with improved survival in some medical and traumatic conditions and with success rates for certain surgical procedures.8, 9, 10, 11, 12, 13 However, there is limited data on the role of hospital volume and OHCA survival.14, 15, 16
In this investigation, we evaluated the relationship between annual OHCA hospital volume and survival to assess the hypothesis that increasing hospital volume of OHCA patients is associated with improved survival.
Section snippets
Study design
This is a cohort investigation of prospectively collected data from the Cardiac Arrest Registry to Enhance Survival (CARES). Started in 2005, CARES is an OHCA registry that has grown each year as new communities, hospitals, and EMS agencies join. As of June 2011, CARES includes 73 EMS agencies serving 40 communities in 23 states and more than 340 hospitals. Details of the registry have been described previously.17, 18 In brief, CARES is a surveillance-based and quality assurance registry
Results
At the time of this analysis, 20,018 patients were in the CARES registry, after applying exclusion criteria, 4125 patients were available for analysis (Fig. 1). Patient characteristics are presented in Table 1.
Those patients taken to the high volume centers were more likely to be African-American and less likely to be of other race (Table 2). Hospital characteristics associated with survival were: number of annual admissions; trauma designation; presence of a cardiac catheterization lab; as
Discussion
In this multicenter, multicity observational study, we did not observe a significant association between increasing OHCA hospital volume and survival in OHCAs of suspected cardiac etiology. While some hospital characteristics, such as trauma center designation and a hospital's use of therapeutic hypothermia, were associated with improved outcomes in OHCA patients, their role with survival requires further exploration. It is possible that the impact of specific hospital attributes, such as the
Conclusion
Although survival varied considerably across hospitals, we observed that receiving hospital OHCA patient volume was not associated with survival to hospital discharge in those with presumed cardiac etiology. Additional efforts are required to determine what hospital characteristics account for the wide variability observed in hospital survival and neurological outcomes following resuscitation from out-of-hospital cardiac arrest.
Funding source
The primary author MTC has funding support from the National Research Program of the American Heart Association (Award # 0835250N).
The Cardiac Arrest Registry to Enhance Survival (CARES) is funded by grant support from the Centers for Disease Control and Prevention (CDC) and Emory University.
Neither funding source had any role in the study design, collection, analysis, interpretation of the data, nor the writing or submission of the manuscript.
Disclosures
None to report.
Conflict of interest statement
None of the authors has any financial and/or personal relationship with people and/or organizations that could inappropriately influence this work.
Acknowledgements
We thank the more than 70 EMS Agencies and more than 340 Hospitals in the CARES registry for all that they do as well as the contributions that their hard work has contributed to this project.
References (45)
Hypothermia improves outcome from cardiac arrest
Crit Care Resusc
(2005)- et al.
Receiving hospital characteristics associated with survival after out-of-hospital cardiac arrest
Resuscitation
(2010) - et al.
Inter-hospital variability in post-cardiac arrest mortality
Resuscitation
(2009) Analyzing grouped data with hierarchical linear modeling
Children Youth Serv Rev
(2005)- et al.
Effect of physician volume on the relationship between hospital volume and mortality during primary angioplasty
J Am Coll Cardiol
(2009) - et al.
Effect of transport interval on out-of-hospital cardiac arrest survival in the OPALS study: implications for triaging patients to specialized cardiac arrest centers
Ann Emerg Med
(2009) - et al.
The feasibility of a regional cardiac arrest receiving system
Resuscitation
(2007) - et al.
A geospatial assessment of transport distance and survival to discharge in out of hospital cardiac arrest patients: implications for resuscitation centers
Resuscitation
(2010) - et al.
Relationship between American College of Surgeons trauma center designation and mortality in patients with severe trauma (injury severity score >15)
J Am Coll Surg
(2006) - et al.
Association between cerebral performance category, modified Rankin scale, and discharge disposition after cardiac arrest
Resuscitation
(2011)
Usefulness of cooling and coronary catheterization to improve survival in out-of-hospital cardiac arrest
Am J Cardiol
Regional variation in out-of-hospital cardiac arrest incidence and outcome
JAMA
Induced hypothermia in critical care medicine: a review
Crit Care Med
Coronary angiography predicts improved outcome following cardiac arrest: propensity-adjusted analysis
J Intensive Care Med
Level 1 cardiac arrest centers: learning from the trauma surgeons
Acad Emerg Med
Take heart America: a comprehensive, community-wide, systems-based approach to the treatment of cardiac arrest
Crit Care Med
Regional systems of care for out-of-hospital cardiac arrest: a policy statement from the American Heart Association
Circulation
Hospital volume and surgical mortality in the United States
N Engl J Med
Do hospitals and surgeons with higher coronary artery bypass graft surgery volumes still have lower risk-adjusted mortality rates?
Circulation
Is volume related to outcome in health care?. A systematic review and methodological critique of the literature
Ann Intern Med
Relationship between trauma center volume and outcomes
JAMA
The association between hospital volume and survival after acute myocardial infarction in elderly patients
N Engl J Med
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2021, American Journal of Emergency MedicineRelationship Between Institutional Volume of Out-of-Hospital Cardiac Arrest Cases and 1-Month Neurologic Outcomes: A Post Hoc Analysis of a Prospective Observational Study
2020, Journal of Emergency MedicineCitation Excerpt :For each institution, we calculated OHCA case volumes by counting the total number of eligible OHCA cases. According to the previous studies, the highest one-third, middle one-third, and lowest one-third of institutions were classified as high-volume, middle-volume, and low-volume centers, respectively, based on the total distribution of cases (5,9). The cutoff values for each group were determined to trisect the number of patients as equally as possible.
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A Spanish translated version of the abstract of this article appears as Appendix in the final online version at doi:10.1016/j.resuscitation.2012.02.006.
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Presented in Poster form at 2011 Society for Academic Emergency Medicine National Research Meeting, Boston, MA, June 2011.
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On behalf of the CARES Surveillance Group. See Appendix A.