Email updates

Keep up to date with the latest news and content from BMC Emergency Medicine and BioMed Central.

Open Access Study protocol

Risk stratification of adult emergency department syncope patients to predict short-term serious outcomes after discharge (RiSEDS) study

Venkatesh Thiruganasambandamoorthy123*, Ian G Stiell123, Marco LA Sivilotti45, Heather Murray46, Brian H Rowe7, Eddy Lang8, Andrew McRae8, Robert Sheldon9 and George A Wells3

  • * Corresponding author: Venkatesh Thiruganasambandamoorthy

Author Affiliations

1 Department of Emergency Medicine, University of Ottawa, Ottawa, Canada

2 Ottawa Hospital Research Institute, Clinical Epidemiology Unit, The Ottawa Hospital, Civic Campus, 1053 Carling Avenue, 6th Floor, Rm F650, Ottawa, Ontario K1Y 4E9, Canada

3 Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, Ontario, Canada

4 Department of Emergency Medicine, Queen’s University, Kingston, Ontario, Canada

5 Department of Biomedical and Molecular Sciences, Queen’s University, Kingston, Ontario, Canada

6 Department of Public Health Sciences, Queen’s University, Kingston, Ontario, Canada

7 Department of Emergency Medicine and School of Public Health, University of Alberta, Edmonton, Alberta, Canada

8 Department of Emergency Medicine, University of Calgary, Calgary, Alberta, Canada

9 Department of Medicine, University of Alberta, Calgary, Alberta, Canada

For all author emails, please log on.

BMC Emergency Medicine 2014, 14:8  doi:10.1186/1471-227X-14-8

Published: 14 March 2014



While Canadian ED physicians discharge most syncope patients with no specific further follow-up, approximately 5% will suffer serious outcomes after ED discharge. The goal of this study is to prospectively identify risk factors and to derive a clinical decision tool to accurately predict those at risk for serious outcomes after ED discharge within 30 days.


We will conduct a prospective cohort study at 6 Canadian EDs to include adults with syncope and exclude patients with loss of consciousness > 5 minutes, mental status changes from baseline, obvious witnessed seizure, or head trauma prior to syncope. Emergency physicians will collect standardized clinical variables including historical features, physical findings, and results of immediately available tests (blood, ECG, and ED cardiac monitoring) prior to ED discharge/hospital admission. A second emergency physician will evaluate approximately 10% of study patients for interobserver agreement calculation of predictor variables. The primary outcome will be a composite serious outcome occurring within 30 days of ED discharge and includes three distinct categories: serious adverse events (death, arrhythmia); identification of serious underlying disease (structural heart disease, aortic dissection, pulmonary embolism, severe pulmonary hypertension, subarachnoid hemorrhage, significant hemorrhage, myocardial infarction); or procedures to treat the cause of syncope. The secondary outcome will be any of the above serious outcomes either suspected or those occurring in the ED. A blinded Adjudication Committee will confirm all serious outcomes. Univariate analysis will be performed to compare the predictor variables in patients with and without primary outcome. Variables with p-values <0.2 and kappa values ≥0.60 will be selected for stepwise logistic regression to identify the risk factors and to develop the clinical decision tool. We will enroll 5,000 patients (with 125 positive for primary outcome) for robust identification of risk factors and clinical decision tool development.


Once successfully developed, this tool will accurately risk-stratify adult syncope patients; however, validation and implementation will still be required. This program of research should lead to standardized care of syncope patients, and improve patient safety.

Syncope; Serious outcomes; Prognosis; Arrhythmia; Emergency department; Management