Date of Award

Fall 2011

Degree Type


Degree Name

Master of Science (MSc)


Health Research Methodology


Lehana Thabane


Carlos Morillo



Committee Member

Marek Smieja


Background: Syncope is estimated to account for 1% to 3% of emergency department (ED) annual visits in North America. Although most potential causes of syncope are benign and self-limited, others are associated with serious morbidity and substantial mortality. Recent efforts have focused on prospective identification of ED patients with syncope who are at high risk for early serious adverse outcomes in an attempt to hospitalize them at their first visit to the ED.

Objective: The purpose of this thesis is to describe the methodological issues related to the design of a study to determine whether the Revised Strategy of Syncope Diagnosis in the Emergency Room at the General Hospital Structured Care Pathway (RESASTER-SCP) is superior to usual care in identifying patients at low risk for serious adverse outcomes presenting to the ED who can be safely discharged home.

Design and Methods: A cluster randomized trial will be conducted with EDs (16 teaching and 46 non-teaching general hospitals) as the unit of randomization and patients presenting with syncope (TLOC) as the unit of analysis. Study participants will be followed at 1, 3, 5, and 12 months after the intervention (RESASTER-SCP vs. usual care) has been applied in the ED. Intention to treat analysis will be used. The analysis will be conducted at the individual level using proportions. Alpha level will be set at 0.05 with a power of 0.80 for the primary outcome.

Conclusion: This thesis describes some of the methodological issues concerning the design of a cluster randomized trial to determine whether or not RESASTER-SCP is superior to usual care in identifying patients presenting with syncope to the ED who can be safely discharged home.

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