Evaluating patients presenting to the emergency department after syncope: validation of the Canadian Syncope Risk Score

Abstract

Study questionOur primary objective is to validate the utility and safety of the Canadian Syncope Risk Score (CSRS) as a clinical decision rule when assessing patients who present with syncope to Australian emergency departments (EDs). Our secondary objective is to evaluate the economic benefits of diverting patients who are at low risk of serious adverse events from admission to hospital. TimetablePhase one of the study will be conducted during March 2018 -March 2019 at the ED of Redcliffe Hospital, an outer metropolitan hospital near Brisbane, which receives 65 000 ED presentations each year. MethodsThis protocol describes phase one of a two-phase validation study. Phase one is an observational prospective validation study. Patients aged 18 or more who present to the ED with syncope, defined as a transient loss of consciousness followed by prompt recovery within the preceding 24 hours, will be recruited as participants. Patients are excluded if they have prolonged syncope (longer than 5 minutes) or persistent reduction in Glasgow Coma Scale (GCS) score, an obvious seizure, intoxication, inability to communicate in English, or major trauma requiring hospitalisation. The study is designed to not influence patient management, with the decision regarding ultimate patient disposition remaining at the discretion of the treating clinician. Demographic and clinical information required to satisfy the domains of the CSRS will be prospectively recorded by the treating clinician, and the CSRS will be calculated retrospectively. Patients will be contacted by telephone 30 days after their initial presentation to the ED for information about any subsequent adverse events.We will undertake a cost-effectiveness analysis from the health care perspective, comparing usual care and applying the CSRS to identify patients at low risk of adverse events who can be safely discharged from the ED instead of being admitted to hospital for further evaluation. Health care costs, including those associated with inpatient stay and admission-related resource use, will be collected from routine administrative databases. Statistical analysisAs phase one is an observational validation study, no formal sample size calculation is required, but we aim to recruit about 500 eligible patients over the one-year period. Data will be summarised as means with standard deviations, medians with interquartile ranges, or frequencies and percentages as appropriate. The diagnostic utility of the CSRS will be assessed by estimating its specificity, sensitivity, positive and negative predictive values, and the area under the receiver operating characteristic (ROC) curve.Parameters included in the economic model will be informed by the collected study data. The outcome of interest is the number of inpatient admissions avoided, with results being presented as costs saved per avoided admission. Health care costs will be included in the economic model and analysed with previously published methods. The results of the economic analysis will be presented as incremental ...

External validation of the Canadian Syncope Risk Score for patients presenting with undifferentiated syncope to the emergency department

“…A recent multi‐centre validation study by the same authors confirmed the robustness of their decision rule which demonstrated high accuracy and reproducibility with patients in the very‐low to low‐risk category having a likelihood of 30‐day SAE in the order of 0.2 and 0.7% respectively 25 . This represents a cohort of low risk patients where hospital admission could be avoided without further significant risk of harm 14 . Our goal in the present study was to externally validate the accuracy and safety of the CSRS in an Australian setting.…”

“…ED physicians, registrars and residents were trained to prospectively enrol patients and collect CSRS predictors using a data collection proforma. An ECG and troponin level were mandated as part of the study protocol 14 . An Internal Medicine physician reviewed and interpreted all ECG variables required to calculate the CSRS for each patient.…”

“…With current pressures on healthcare resources and increasing hospital congestion, clinicians need a safe and efficient approach in managing patients presenting to ED with syncope. This includes identifying those at high‐risk who would benefit from admission and further testing but also avoiding unnecessary admission of low risk patient groups 14 . Given a definitive diagnosis is not often achieved in ED, the cornerstone of management relies on accurate risk stratification to determine safe disposition 2,9,15–17 …”

“…Multiple clinical decision rules have been developed over the years to aid in this decision process 12,16,18–20 . None have been universally adopted because of performance inconsistencies in validation studies across different populations 14,18,21–23 …”

Economic evaluation of applying the Canadian Syncope Risk Score in an Australian emergency department

“…4 Due to the heterogeneity of underlying causes, with some potentially life threatening, the management of syncope has been problematic especially following nondiagnostic evaluation in ED. [5][6][7][8] This has led to a conservative approach and high hospitalisation rates. 9 This approach is not only costly but adds little to the overall management and prognosis of patients admitted with syncope.…”