F2 and chronic obstructive pulmonary disease: CRP: C-reactive protein; INR: international normalized ratio; PTT: prothrombin time; LDH: lactate dehydrogenase; BMI: body mass index, kg/m2; VTE: venous thromboembolism; DVT: deep vein thrombosis; COPD: chronic obstructive pulmonary disease; NIPPV: non-invasive positive pressure ventilation lung disease - included COPD, asthma and interstitial lung disease malignancy - included all malignancies, both active and those with prior history of same.