Toward better utilization of laboratory resources: The impact of a mandatory 4Ts pretest clinical assessment form on the diagnosis of heparin-induced thrombocytopenia

Background: Frequency rates for heparin-induced thrombocytopenia range from 0.5% to 5.0% of all heparin-treated patients. The most readily available laboratory tests are very sensitive for heparin-dependent platelet factor 4 antibodies, but are not specific for heparin-induced thrombocytopenia. Tests with greater specificity are more technically demanding and less readily available. In addition to laboratory testing, four clinical …