A Method for Grouping Emergency Department Visits by Severity and Complexity.


INTRODUCTION:Triage functions to quickly prioritize care and sort patients by anticipated resource needs. Despite widespread use of the Emergency Severity Index (ESI), there is still no universal standard for emergency department (ED) triage. Thus, it can be difficult to objectively assess national trends in ED acuity and resource requirements. We sought to derive an ESI from National Hospital Ambulatory Medical Care Survey (NHAMCS) survey items (NHAMCS-ESI) and to assess the performance of this index with respect to stratifying outcomes, including hospital admission, waiting times, and ED length of stay (LOS). METHODS:We used data from the 2010-2015 NHAMCS, to create a measure of ED visit complexity based on variables within NHAMCS. We used NHAMCS data on chief complaint, vitals, resources used, interventions, and pain level to group ED visits into five levels of acuity using a stepwise algorithm that mirrored ESI. In addition, we examined associations of NHAMCS-ESI with typical indicators of acuity such as waiting time, LOS, and disposition. The NHAMCS-ESI categorization was also compared against the "immediacy" variable across all of these outcomes. Visit counts used weighted scores to estimate national levels of ED visits. RESULTS:The NHAMCS ED visits represent an estimated 805,726,000 ED visits over this time period. NHAMCS-ESI categorized visits somewhat evenly, with most visits (42.5%) categorized as a level 3. The categorization pattern is distinct from that of the "immediacy" variable within NHAMCS. Of admitted patients, 89% were categorized as NHAMCS-ESI level 2-3. Median ED waiting times increased as NHAMCS-ESI levels decreased in acuity (from approximately 14 minutes to 25 minutes). Median LOS decreased as NHAMCS-ESI decreased from almost 200 minutes for level 1 patients to nearly 80 minutes for level 5 patients. CONCLUSION:We derived an objective tool to measure an ED visit's complexity and resource use. This tool can be validated and used to compare complexity of ED visits across hospitals and regions, and over time.






Published Version (Please cite this version)


Publication Info

Theiling, Brent, Kendrick Kennedy, Alexander Limkakeng, Pratik Manandhar, Alaattin Erkanli and Stephen Pitts (2020). A Method for Grouping Emergency Department Visits by Severity and Complexity. The western journal of emergency medicine, 21(5). pp. 1147–1155. 10.5811/westjem.2020.6.44086 Retrieved from https://hdl.handle.net/10161/21615.

This is constructed from limited available data and may be imprecise. To cite this article, please review & use the official citation provided by the journal.



Brent Jason Theiling

Associate Professor of Emergency Medicine


Dr. Theiling is a board-certified emergency medicine physician with expertise in Emergency Department and hospital operations. He is currently the vice chair of operations for Duke University's Department of Emergency Medicine, as well as CSU Medical Director of the Emergency Services Clinical Service Unit for Duke University Hospital. This unit encompasses Duke's Emergency Department, Life Flight Critical Care transport teams, the Duke Trauma Center, Patient Transport and Emergency Management.

As an Associate Professor of Emergency Medicine at Duke University School of Medicine and works in providing high-quality emergency care.. Dr. Theiling also provides cutting-edge education to future emergency medicine providers, focusing on clinical emergency medicine and critical care, advancements in medical education and emergency department operations.

Dr. Theiling is also a member of the Duke Emergency Medicine Residency Core Faculty and has won multiple awards for his work in education and clinical care. He has over a dozen publications in peer-reviewed journals about clinical emergency medicine, advancements in medical education, emergency department operations and work with Duke Life Flight. He works closely with AMPA and is active in the organization.


Kendrick V Kennedy

Assistant Professor of Emergency Medicine

Dr. Kennedy’s professional interests include advocacy, education, and service for marginalized populations. This includes working with community leaders to address social determinants of health and the emergency physicians' role in this process.  Dr. Kennedy’s work within the community of Durham has given him an appreciation of strong community connections and the importance of understanding the resources that are available for the patients he serves. With that knowledge Dr. Kennedy strives to combine clinical knowledge, a great work ethic and a highly professional attitude to provide excellent patient care.


Alexander Tan Limkakeng

Professor of Emergency Medicine

Dr. Alexander T. Limkakeng, Jr., MD, MHSc, FACEP is a Professor of Emergency Medicine, Vice Chair of Clinical Research, Director of the Acute Care Research Team, and Director of the Resident Research Fellowship for the Department of Emergency Medicine in the Duke University School of Medicine in Durham, North Carolina.

Dr. Limkakeng has served as chair of the American College of Emergency Physicians (ACEP) Research Committee, and been the Course Director of the ACEP Research Forum from 2016-2018, the largest emergency medical research platform in the nation. He is also the Assistant Director of ACEP’s Emergency Medicine Basic Research Skills course. He was elected to the Nominating Committee of the Society of Academic Emergency Medicine.

As a researcher, Dr. Limkakeng has led multiple clinical trials and interdepartmental sponsored projects and is author on over 100 peer-reviewed manuscripts. These include studies in emergency conditions such as COVID-19, traumatic brain injury, hypertension, heart failure, thrombosis, stroke, envenomations, and septic shock. His research has been funded by grants and contracts totaling over $9 million dollars. He has lectured internationally on acute coronary syndrome, responsible conduct of research, design of clinical trials, and precision medicine in emergency care. He has led Duke’s involvement in NIH-funded research networks and in industry-funded work that led to FDA approval for multiple high-sensitivity cardiac troponin assays and point-of-care COVID-19 diagnostic tests. He has servesd as Co-PI for the Duke U24 Hub in the NIH Early Phase Pain Investigation Clinical Network (EPPIC-Net) (1U24NS114416) and now serves as a co-PI on the Duke U24 Hub award (1U24NS129498) in the NIH Strategies to Innovate Emergency Care Clinical Trials (SIREN) Network and in the NIH NINDS Strokenet network (1U24NS135250)

His personal research interest is finding new ways to diagnose acute coronary syndrome. In particular, he is interested in novel biomarkers and precision medicine approaches to this problem. The common element throughout this work is a focus on time-sensitive health conditions.

Unless otherwise indicated, scholarly articles published by Duke faculty members are made available here with a CC-BY-NC (Creative Commons Attribution Non-Commercial) license, as enabled by the Duke Open Access Policy. If you wish to use the materials in ways not already permitted under CC-BY-NC, please consult the copyright owner. Other materials are made available here through the author’s grant of a non-exclusive license to make their work openly accessible.