Risk-stratification tools for emergency department patients with syncope: a systematic review and meta-analysis of direct evidence for SAEM GRACE

<p dir="ltr"><b>Objectives:</b><b> </b>Approximately 10% of patients with syncope have serious or life-threatening causes that may not be apparent during the initial emergency department (ED) assessment. Consequently, researchers have developed clinical decision rules (CDRs) to predict adverse outcomes and risk stratify ED syncope patients. This systematic review and meta-analysis (SRMA) aims to cohere and synthesize the best current evidence regarding the methodological quality and predictive accuracy of CDRs for developing an evidence-based ED syncope management guideline. <p dir="ltr"><b>Methods:</b><b> </b>We conducted a systematic literature search according to the patient-intervention-control-outcome question: In patients 16 years of age or older who present to the ED with syncope for whom no underlying serious/life-threatening condition was found during the index ED visit (population), are risk stratification tools (intervention), better than unstructured clinical judgment (i.e., usual care; comparison), for providing accurate prognosis and aiding disposition decision for outcomes within 30 days (outcome)? Two reviewers independently assessed articles for inclusion and methodological quality. We performed statistical analysis using Meta-DiSc. We used GRADEPro GDT software to determine the certainty of the evidence and create a summary of the findings (SoF) tables. <p dir="ltr"><b>Results:</b><b> </b>Of 2047 publications obtained through the search strategy, 31 comprising 13 CDRs met the inclusion criteria. There were 13 derivation studies (17,578 participants) and 24 validation studies (14,845 participants). Only three CDRs were validated in more than two studies. The San Francisco Syncope Rule (SFSR) was validated in 12 studies: positive likelihood ratio (LR+) 1.15-4.70 and negative likelihood ratio (LR-) 0.03-0.64. The Canadian Syncope Risk Score (CSRS) was validated in five studies: LR+ 1.15-2.58 and LR- 0.05-0.50. The Osservatorio Epidemiologico sulla Sincope nel Lazio (OESIL) risk score was validated in five studies: LR+ 1.16-3.32 and LR- 0.14-0.46. <p dir="ltr"><b>Conclusions:</b><b> </b>Most CDRs for ED adult syncope management have low-quality evidence for routine clinical practice use. Only three CDRs (SFSR, CSRS, OESIL) are validated by more than two studies, with significant overlap in operating characteristics.