Clinical decision support to aid in diagnosis of heparin-induced thrombocytopenia

Clinical decision support (CDS) can potentially improve the rate of heparin-induced thrombocytopenia (HIT) diagnostic testing for patients who are at increased risk. We implemented and evaluated CDS utilizing the HIT computerized risk (HIT-CR) score in a large healthcare system. The CDS was triggered by a HIT-CR score of 4 and provided clinicians with a temporal graph of platelet counts and prompts to help further assess the risk of HIT. The primary outcome of this study was the percentage of patients at intermediate to high risk for HIT (4Ts scores ≥4) who underwent recommended diagnostic testing for HIT. Among those with 4Ts scores ≥4, the diagnostic testing rate increased from 28/237 (11.8%) to 98/288 (34.0%) (p < 0.0001) after implementation of the CDS advisory. The rate of patients determined to have HIT was 6/332 (1.8%) pre-intervention and 13/412 (3.2%) post-intervention (p = 0.25). Fourteen of the 26 patients with 4Ts scores ≥6 did not undergo diagnostic testing for HIT despite the CDS advisory, and eight had possible complications from undiagnosed HIT. A CDS tool using the HIT-CR score for assessment of risk of HIT can increase the rate of diagnostic testing in patients with elevated risk of HIT, but there is potential for further improvement.