Table 1

Characteristics of the study design and study population

First author, year	Country	Type	Patients, n	Mean age, year	Female, %	Prevalence of CAD/ACS, %	Follow-up period
Coronary artery disease
Gencer rule
Gencer et al,7 2010	Switzerland	Derivation	661	55.4	52.5	12.9	1 year
Gencer et al,7 2010	Germany	External validation	774	N/A	58.0	14.7	6 months
Marburg Heart Score
Bösner et al,15 2010	Germany	Derivation	1249	59	43.9	14.4	6 months
Bösner et al,15 2010	Switzerland	External validation	672	55	47.6	12.6	1 year
Haasenritter et al,16 2012	Germany	External validation	844	59.5	51.5	10.9	6 months
Haasenritter et al,17 2015	Germany	External validation	578	60.2	51.7	12.1	6 months
INTERCHEST*
Aerts et al,14 2017	USA, Belgium, Sweden, Switzerland, Germany	Derivation	3099	N/A	N/A	12.5	N/A
	Switzerland	Validation in study 1	644	55.4	52.3	13.2	1 year
	Germany	Validation in study 2	1238	59.4	56.2	14.5	6 months
Acute coronary syndrome
Grijseels rule
Grijseels et al,13 1995	The Netherlands	Derivation	906	67	46	46.2	30 days
Grijseels et al,12 1996	The Netherlands	Validation	977	65.6	47	47.8	30 days
Bruins Slot rule
Bruins Slot et al,11 2011	The Netherlands	Derivation	298	66	52	22	30 days
Aerts et al,14 2017	USA, Belgium, Sweden, Switzerland, Germany	Sensitivity analysis	169	N/A	N/A	N/A	N/A

*Derivation used pooled individual patient data from five studies. The INTERCHEST was applied to two of these five studies to measure its diagnostic performance. We referred to this as ‘validation in study 1 and 2’.
ACS, acute coronary syndrome; CAD, coronary artery disease; N/A, not applicable.