The Development of a Risk-Adjustment Strategy to Benchmark Emergency Medical Service (EMS) Performance in Relation to Out-of-Hospital Cardiac Arrest in Australia and New Zealand

Howell, Stuart
Smith, Karen
Finn, Judith
Cameron, Peter
Ball, Stephen
Bosley, Emma
Doan, Tan
Dicker, Bridget
Faddy, Steven
Nehme, Ziad
Item type
Journal Article
Degree name
Journal Title
Journal ISSN
Volume Title

INTRODUCTION: The aim of this study was to develop a risk adjustment strategy, including effect modifiers, for benchmarking emergency medical service (EMS) performance for out-of-hospital cardiac arrest (OHCA) in Australia and New Zealand.

METHOD: Using 2017-2019 data from the Australasian Resuscitation Outcomes Consortium (Aus-ROC) OHCA Epistry, we included adults who received an EMS attempted resuscitation for a presumed medical OHCA. Logistic regression was applied to develop risk adjustment models for event survival (return of spontaneous circulation at hospital handover) and survival to hospital discharge/30 days. We examined potential effect modifiers, and assessed model discrimination and validity.

RESULTS: Both OHCA survival outcome models included EMS agency and the Utstein variables (age, sex, location of arrest, witnessed arrest, initial rhythm, bystander cardiopulmonary resuscitation, defibrillation prior to EMS arrival, and EMS response time). The model for event survival had good discrimination according to the concordance statistic (0.77) and explained 28% of the variation in survival. The corresponding figures for survival to hospital discharge/30 days were 0.87 and 49%. The addition of effect modifiers did little to improve the performance of either model.

CONCLUSION: The development of risk adjustment models with good discrimination is an important step in benchmarking EMS performance for OHCA. The Utstein variables are important in risk-adjustment, but only explain a small proportion of the variation in survival. Further research is required to understand what factors contribute to the variation in survival between EMS.

Emergency medical services , Heart arrest , Out of hospital cardiac arrest , Registries , Resuscitation , Aus-ROC OHCA Epistry Management Committee , 4203 Health Services and Systems , 32 Biomedical and Clinical Sciences , 3202 Clinical Sciences , 42 Health Sciences , Heart Disease , Emergency Care , Cardiovascular , Cardiovascular , 1103 Clinical Sciences , 1110 Nursing , 1117 Public Health and Health Services , Emergency & Critical Care Medicine , 3202 Clinical sciences , 4205 Nursing , 4206 Public health
Resuscitation, ISSN: 0300-9572 (Print); 1873-1570 (Online), Elsevier, 188, 109847-. doi: 10.1016/j.resuscitation.2023.109847
Rights statement