Effectiveness of a clinical decision support system to identify heparin induced thrombocytopenia.

BACKGROUND: Subtle decreases in platelet count may impede timely recognition of heparin-induced thrombocytopenia (HIT), placing the patient at increased risk of thrombotic events. OBJECTIVE: A clinical decision support system (CDSS) was developed to alert physicians using computerized provider order entry when a patient with an active order for heparin experienced platelet count decreases consistent with HIT. METHODS: Comparisons for timeliness of HIT identification and treatment were evaluated for the year preceding and year following implementation of the CDSS in patients with laboratory confirmation of HIT. RESULTS: During the intervention time period, the CDSS alert occurred 41,922 times identifying 2,036 patients who had 2,338 inpatient admissions. The CDSS had no significant impact on time from fall in platelet count to HIT laboratory testing (control 2.3 days vs intervention 3.0 days P = 0.30) and therapy (control 19.3 days vs intervention 15.0 days P = 0.45), and appeared to delay discontinuation of heparin products (control 1.3 days vs. intervention 2.9 days P = 0.04). However, discontinuation of heparin following shorter exposure duration and after smaller decrease in platelet count occurred during the intervention period. The HIT CDSS sensitivity and specificity were each 87% with a negative predictive value of 99.9% and positive predictive value of 2.3%. CONCLUSIONS: Implementation of a CDSS did not appear to improve the ability to detect and respond to potential HIT, but resulted in increased laboratory testing and changes in clinician reactions to decreasing platelet counts that deserve further study.