A new lab order, Heparin-Induced Thrombocytopenia Antibody (HIT AB) will be available January 2, 2019. This order will provide decision support for providers: 1) Is HIT AB test necessary for my patient? 2) Results from HIT AB will reflex Serotonin Release Assay (SRA) when needed.

When completed, the HIT Powerform shown below will result with a 4Ts Score of 0-8. This will be the first step to provide probability of HIT diagnosis. When signing the order, a 4Ts score of less than 3 shows a probability of 1.9%. With low probability for HIT, there is the option to Cancel or Override the order for HIT AB. When the 4Ts score is more than 3, the order for HIT AB is placed after signing.

Below are the probabilities of HIT given each HIT AB negative result along with each possible 4Ts score from the PowerForm and each positive result for HIT AB along with the possible 4Ts Score. When HIT AB is detected, the probability of HIT diagnosis increases and Serotonin Release Assay (SRA) will reflex to confirm.