Reduced prothrombin consumption HP:0003337 Poor prothrombin consumption HP:0008172 UMLS:C4021732 The prothrombin consumption test measures the formation of intrinsic thromboplastin by determining the residual serum prothrombin after blood clotting is complete. If there is a defect in the process, less prothrombin will be converted to thrombin than normal (less prothrombin is consumed). This test may be abnormal with conditions including deficiency of factors VIII or IX, with circulating anticoagulants, thrombocytopenia. Abnormality of prothrombin