Modified Wells criteria for predicting pumonary embolism(PE) Variable Score Clinical signs and symptoms DVT (minimum of leg swelling and pain on palpation of deep veins) 3 Alternative diagnosis less likely than PE 3 Hea rate >100 bpm 1.5 Immobilization > 3 days or surgery within past 4 weeks 1..5 Previous DVT OR PE 1.5 Haemoptysis 1 Malignancy (including treatment within past 6 months ) 1 LOW RISK: <2 MODERATE RISK: 3-6 HIGH RISK: >6