Background Published risk tools do not provide possible management options for syncope in the emergency department (ED). Using the 30-day observed risk estimates based on the Canadian Syncope Risk Score (CSRS), we developed personalised risk prediction to guide management decisions.
Methods We pooled previously reported data from two large cohort studies, the CSRS derivation and validation cohorts, that prospectively enrolled adults (≥16 years) with syncope at 11 Canadian EDs between 2010 and 2018. Using this larger cohort, we calculated the CSRS calibration and discrimination, and determined with greater precision than in previous studies the 30-day risk of adjudicated serious outcomes not identified during the index ED evaluation depending on the CSRS and the risk category. Based on these findings, we developed an on-line calculator and pictorial decision aids.
Results 8233 patients were included of whom 295 (3.6%, 95% CI 3.2% to 4.0%) experienced 30-day serious outcomes. The calibration slope was 1.0, and the area under the curve was 0.88 (95% CI 0.87 to 0.91). The observed risk increased from 0.3% (95% CI 0.2% to 0.5%) in the very-low-risk group (CSRS −3 to –2) to 42.7% (95% CI 35.0% to 50.7%), in the very-high-risk (CSRS≥+6) group (Cochrane-Armitage trend test p<0.001). Among the very-low and low-risk patients (score −3 to 0), ≤1.0% had any serious outcome, there was one death due to sepsis and none suffered a ventricular arrhythmia. Among the medium-risk patients (score +1 to+3), 7.8% had serious outcomes, with <1% death, and a serious outcome was present in >20% of high/very-high-risk patients (score +4 to+11) including 4%–6% deaths. The online calculator and the pictorial aids can be found at: https://teamvenk.com/csrs
Conclusions 30-day observed risk estimates from a large cohort of patients can be obtained for management decision-making. Our work suggests very-low-risk and low-risk patients may be discharged, discussion with patients regarding investigations and disposition are needed for medium-risk patients, and high-risk patients should be hospitalised. The online calculator, accompanied by pictorial decision aids for the CSRS, may assist in discussion with patients.
- emergency department
Data availability statement
No data are available.
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Handling editor Edward Carlton
Contributors VT, JWY, BHR, EM, NLS, MH, PH, MM, ADM, MT and MLAS conceived the idea, contributed to the study design, developed the study protocol and applied for funding. VT, JY, BHR, EM, NLS, MH, AF, PH, MM, PAN, ADM, M-JN, MT and MLAS supervised the conduct of the studies including recruitment of patients, data collection, data management including quality control. MT provided statistical advice on study design. M-JN analysed the data under MT’s supervision. HM, PAN and SS interpreted the results, designed and developed the online calculator, pictograms and patient information materials. VT drafted the manuscript. All authors reviewed the manuscript and contributed substantially to its revision. VT takes responsibility for the paper as a whole.
Funding The two prospective studies from which these data were taken were funded by The Physicians’ Services Incorporated Foundation (09q4017), Canadian Institutes of Health Research (MOP-114927), Heart and Stroke Foundation Canada (G-15–0009006), and the Cardiac Arrhythmia Network of Canada (SRG-15-P10-001) as part of the Networks of Centres of Excellence (NCE).
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
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