Value of red blood cell distribution width on emergency department admission in patients with venous thrombosis

Red blood cell distribution width (RDW) was found to be a useful parameter in a variety of cardiovascular and thrombotic disorders. Therefore, we conducted a retrospective case-control study to establish whether an association exists between RDW and venous thrombosis. The study population consisted of 431 consecutive patients who received a diagnosis of venous thrombosis in the emergency department (ED), thus including cases of superficial venous thrombosis, deep vein thrombosis (DVT), and/or pulmonary embolism (PE). The control population consisted of 967 matched outpatients who underwent routine laboratory testing. The RDW values were found to be significantly increased in patients with venous thrombosis compared to controls, with an incremental trend of values from patients with superficial thrombosis, isolate DVT, to PE. Increased RDW values were an independent risk factor for isolate DVT and PE, displaying a relative risk that was greater in patients with provoked DVT and PE that in those with unprovoked thrombosis after multiple adjustment for age, gender, hemoglobin, and mean corpuscular volume. Interestingly, RDW also exhibited a significant diagnostic performance at ED admission, displaying an area under the curve of 0.65 (95% confidence interval [CI] 0.62 to 0.68; p <0.001) for all cases of venous thrombosis, 0.63 (95% CI 0.59 to 0.68; p <0.001) for isolate DVT, and 0.70 (95% CI 0.65 to 0.75; p <0.001) for PE. The results of this study suggest that increased RDW not only is associated with venous thrombosis but may also increase the efficiency of baseline risk assessment of patients with suspected venous thrombosis on ED admission.