Seven tests were compared in blood samples collected from normal individuals and patients with venous thrombosis. Three tests were found to have significance for discrimination: platelet entrapment in glass spheres, the hematocrit, and partial thromboplastin time of dilute plasma. A good, but incomplete, separation of individuals was effected by using a discriminant function based on these three variables.
Hume M, Chan Y. Examination of the Blood in the Presence of Venous Thrombosis. JAMA. 1967;200(9):747–750. doi:10.1001/jama.1967.03120220049007