Table 1.

Emergency department syncope studies

No	Year	Study	Variables	Scoring system	Endpoints	Results1	Strengths	Weakness
1	1997	Martin et al.	• Abnormal ECG	0 to 4	1-year arrhythmias or deaths	4.4% score 0	One of the earliest studies	Only long-term outcomes
			• History of ventricular arrhythmia	(1 point for each item)
			• History of CHF			57.6% score 3 or 4		Not validated
			• Age >45 years
2	2002	OESIL	• Abnormal ECG	0 to 4	1-year mortality	0% score 0	Externally validated for	Only long-term outcomes
			• History of cardiovascular disease	(1 point for each item)		0.6% score
			• Lack of prodrome			14% score 2	up to 6 month outcomes	Modest performance for outcomes up to 6 months
			• Age >65 years
						29% score 3
						53% score 4
3	2003	Sarasin et al.	• Age >65 years	0 to 3	Arrhythmias in unexplained ED syncope	2% score 0	Studied arrhythmia risk in unexplained syncope	Only inpatients
			• History of CHF	(1 point for each item)		17% score 1		Internal validation on historical cohort
			Abnormal ECG			35% score 2
						27% score 3
								No external validation
4	2004	San Francisco Syncope Rule	• Abnormal ECG	No item = No risk	7-day serious events	Sensitivity 98%	First tool for short-term events	Wide variations in performance
			• History of CHF
			• Shortness of breath
			• Hematocrit < 30%	≥ 1 item = risk		Specificity 56%	Most widely validated	ECG variable too broad
			• Triage systolic BP <90 mmHg
								Included soft outcomes2
5	2007	Boston Syncope Rule	• Compilation of 25 plausible variables	≥ 1 item = risk	30-day serious events	Sensitivity 97%	A thorough list of variables	No statistical methods
						Specificity 62%		Not practical
								No external validation
6	2008	STePS	• Abnormal ECG	≥ 1 item = risk	10-day and 1-year events	Not Reported	Addresses the role of admissions to hospital	Readmission to hospital was an outcome
			• Trauma
			• No prodrome
			• Male sex
								Not validated
7	2008	EGSYS	• Palpitations before syncope (+4)	Addition of all items	Cardiac syncope probability	2% score <3	First study to incorporate variables from history	Not generalizable - Syncope expert always available
			• Abnormal ECG and/or heart disease (+3)
			• Syncope during effort (+3)		2-year total mortality	13% score 3
			• Syncope while supine (+2)			33% score 4
						77% score >4		Internal validation 92% sensitivity
						2% score <3
						21% score ≥3		No robust external validation
			• Autonomic prodrome (−1)
8	2009	Sun et al.	• Age >90 years (+1)	Addition of all items	30-day events among older (≥ 60 years) syncope patients	2.5% score −1, 0	First study to risk stratify older patients	Retrospective
			• Male sex (+1)
			• History of arrhythmia (+1)			6.3% score 1,2		Can be applied only to older patients
			• Triage systolic BP >160 (+1)				Large sample size
			• Abnormal ECG (+1)
			• Abnormal troponin I (+1)			20% score 3 to 6		Not validated
			• Near-syncope (−1)
9	2010	ROSE	• BNP level ≥300 pg/ml	Presence of any item	1-month serious events	Sensitivity 87%	First study to evaluate the role of BNP in risk stratification	Short-term events included stroke
			• Bradycardia ≤50 in ED/pre-hospital
			• Positive fecal occult blood on rectal			Specificity 66%
			• Anemia – Hemoglobin ≤ 90 g/L					Requires BNP testing that is not widely available
			• Chest pain with syncope
			• Q wave on ECG (except in lead III)
			• O2 saturation ≤ 94% on room air					Less than ideal sensitivity

ECG = Electrocardiogram, CHF = Congestive Heart Failure, OESIL = Osservatorio Epidemiologico sulla Sincope nel Lazio, BP = Blood Pressure, STePS = Short-Term Prognosis of Syncope, EGSYS = Evaluation of Guidelines in Syncope Study, BNP = Brain type or B-type Natriuretic Peptide.

¹Results of validation phase when available.

²Soft outcomes = Cortical stroke and hospitalization on return visit with no serious events.

All studies used standard statistical methods to develop the tool except the Boston Syncope Rule study.