Table 1

Characteristics of included cohorts

Author, year, countryN (% female)Age, mean (SD) or median (IQR)Subject selectionOutcome definitionPE prevalenceDuration of follow-up, days
Wolf, 2008, USA134 (54.0)58 (43–72)Adults 18–85 years with clinically suspected PE, chest radiograph and ECG included.Exclusion: pregnant, haemodynamically unstable, known D-dimer level in recent pastCombination of:
▸ high probability V/Q scan using modified prospective investigation of PE diagnosis criteria
intermediate probability V/Q scan with a high pretest clinical suspicion
▸ contrast-enhanced CT scan chest pulmonary angiogram
▸ diagnosis of VTE
Hogg, 2005, UK425 (51.1)38.3 (15.0)Adults (>18 years) presented to ED with pleuritic chest pain.
Exclusion: pneumothorax, ECG changes of myocardial infarction, ischaemia or pericarditis, pregnancy or trauma within 4 weeks
Combination of:
▸ high probability V/Q scan with high clinical probability
▸ CT-pulmonary angiography
▸ digital subtraction angiography
Kline, 2004, USA, LR1427 (60.0)47 (17)Adults (>18 years) with clinical suspicion for PE that emergency physicians believed were at LR to justify exclusion of PE on the basis of a negative D-dimerCombination of:
▸ CT angiography
▸ CT angiography-venography
▸ V/Q scan (followed by duplex ultrasound of the extremities)
Kline, 2004, USA, VLR382 (56.0)56 (18)Adults (>18 years) presenting with shortness of breath but emergency physician stated PE not the most likely diagnosisCombination of:
▸ CT angiography
▸ CT angiography-venography
▸ V/Q scan (followed by duplex ultrasound of the extremities)
Dachs, 2010, USA213All the ED patients who underwent a CT scan to rule out PECT chest8.590
Hugli, 2011, Switzerland, France, Belgium1675 (56.7)61 (45–76)Adult outpatients treated in the ED with a clinical suspicion of PE.
Exclusion: contraindication to multidetector CT (MDCT) (ie, allergy to iodine contrast agents, creatine clearance < 30 ml/min or pregnancy), a terminal illness with an expected survival of <3 months, a previous documented diagnosis of PE or were receiving anticoagulant therapy at presentation
Combination of:
▸ positive MDCT or pulmonary angiography
▸ high probability V/Q scan
▸ proximal deep vein thrombosis documented by compression ultrasonography
Beam, 2007, USA189Adults (>18 years) with clinical suspicion for PE for whom emergency physicians considered formal PE evaluation necessaryCombination of:
▸ CT scan and V/Q scan
Righini, 2005, Switzerland762 (58.0)61 (19)Consecutive outpatients suspected of PECombination of:
▸ clinical probability assessment
▸ D-dimer measurement
▸ venous ultrasonography (USA)
▸ helical CT
▸ pulmonary angiogram
Crichlow, 2011, USA110 (74)46.4 (30.8–62.0)Patients who received CTpulmonary angiography or lower-extremity duplex ultrasonographyCombination of:
▸ CT-pulmonary angiography
▸ Lower-extremity duplex
▸ Ultrasonography
Kline, 2010, USA110ED patients (>17 years) admitted with chief complaints: chest pain, shortness of breath, respiratory distress, syncope, hypotension,palpitations, cough, altered mental status or syntax indicating that the patient was sent from outside facility for PE evaluationCombination of:
▸ D-dimer
▸ pulmonary vasculature imaging
▸ venous ultrasonography
Courtney, 2006, USA315ED patients with any testing (V/Q scan, CTscan or D-dimer test) to evaluate for PECombination of:
▸ V/Q scan
▸ CT scan
▸ D-dimer test
Kline, 2008, USA, New Zealand8138 (67.0)49.1Adults (≥18 years) with clinical suspicion for PE on ED physician's evaluation.
Exclusion: (1) positive pulmonary vascular imaging study in last 7 days, (2) patient indicated that the enrolment hospital was not his or her choice for follow-up or (3) patient would be lost to follow-up (eg, homeless, psychiatric disorders, international travellers, person arrested for felonies)
Combination of:
▸ either a high probability V/Q scan or
▸ CT angiogram or
▸ conventional pulmonary angiogram or
▸ PE on autopsy
Penaloza, 2012, Belgium, France959 (62.0)63.9 (0.6)Consecutive patients with suspected PE who presented to EDs. Exclusion: (1) the diagnosis of thromboembolic disease wasdocumented before admission; (2) PE was suspected during a hospital stay of more than 2 days duration; or (3) diagnostic testing was cancelled for ethical reasons, because of rapid death or because the patient decided to leave the hospital against medical adviceCombination of:
▸ either a high probability V/Q scan or spiral CT
▸ venous compression ultrasonography
▸ pulmonary angiogram
▸ PE on autopsy
  • ED, emergency department; LR, low risk; PE, pulmonary embolism; V/Q scan, ventilation-perfusion scan; VLR, very low risk; VTE, venous thromboembolism.