TABLE 1.

Two-level Wells score for estimating the clinical probability of pulmonary embolism (PE)

Parameter	Score
Clinically suspected DVT	3
Alternative diagnosis less likely than PE	3
Rapid heart rate	1.5
Immobilisation for >3 days or surgery within the past 4 weeks	1.5
History of VTE	1.5
Haemoptysis	1
Malignancy	1

After adding the total points together, a score >6 indicates a high probability of PE; 2−6 a moderate probability; and <2 a low probability. The NICE 2012 guidelines suggest that a score of >4 points indicates PE likely and ≤4 points indicates PE unlikely [9, 19]. DVT: deep vein thrombosis; VTE: venous thromboembolism.