Table 2 Follow up studies for analysis.

Author	Country and year	Inclusion criteria	Outpatients (%)	Prevalence of PE	False negatives (%)	Study appraisal scores: 0 = no criteria fulfilled, 1 = only some criteria fulfilled, 2 = all criteria fulfilled.
						Follow up	Study cohort	Included patients	Excluded patients	CTPA protocol
Musset et al28	France 2002	All patients suspected of pulmonary embolism	77%	35%	68/638	2	1	1	1	2
Tillie‐Leblond et al29	France 2002	All patients suspected of pulmonary embolism	85%	30%	19/201	1	1	2	1	2
van Strijen et al30	Holland 2003	All patients suspected of pulmonary embolism	54%	24%	5/378	2	1	1	1	2
Perrier et al31	Switzerland, France 2004	Elevated D‐dimer and normal ultrasound	100%	23%	9/413	2	1	2	2	2
Perrier et al32	Switzerland, France 2005	Elevated D‐dimer or high clinical probability of pulmonary embolism	100%	26%	8/324	2	1	2	1	2
Ferretti et al33	France 1997	Normal ultrasound and intermedate VQ scan	35%	24%	7/112	1	1	1	1	2
Ost et al34	USA 2001	Patients with high clinical probability of PE and non‐diagnostic VQ scan	Unknown	27%	3/71	1	1	1	1	2
Remy‐Jardin et al35	France 2002	Patients referred for CT pulmonary angiogram	17%	18%	11/173	1	1	1	1	2
Friera et al36	Spain 2004	Patients referred for CT pulmonary angiogram	Unknown	25%	1/115	1	1	1	0	2
Revel et al37	France 2005	Patients referred for CT pulmonary angiogram	44%	24%	7/140	1	1	1	0	2
Prologo et al38	USA 2005	Patients referred for CT pulmonary angiography	Unknown	10%	2/198	1	1	1	1	2