The Cost of HIT-Safe Anticoagulant Use at a Tertiary Care, Adult, Academic Hospital.

Abstract

Objective: Heparin-induced thrombocytopenia (HIT) is a potential adverse outcome of heparin therapy. At Sunnybrook Health Sciences Centre (SHSC), a patient suspected of HIT has heparin discontinued, a HIT enzyme-linked immunosorbent assay (ELISA) ordered, and is then treated with a HIT-safe anticoagulant. Few studies have assessed the cost of treating suspected (negative and confirmed) HIT. The objective of our study was to quantify the direct costs associated with treating HIT from a Canadian hospital perspective.Methods: A cost analysis was conducted at SHSC, a 701-bed academic hospital with cardiac surgery. Suspected HIT included all patients who had a HIT ELISA ordered. A confirmed HIT case had one of the following:positive serotonin release assay (SRA),positive HIT ELISA (optical density: 0.4 to 1.0) plus high clinical probability for HIT, orstrongly positive HIT ELISA (optical density > 1.0).A negative HIT case had a negative HIT ELISA or SRA. Costs associated with using HIT-safe anticoagulants included:drug acquisition,preparation time,monitoring tests, andthe management of bleeding (e.g., blood transfusions).The average treatment cost (2007 Canadian dollars) per case of confirmed HIT, confirmed HIT with thrombosis (HITT), and negative HIT was calculated. Cost data was obtained from the hospital human resources, pharmacy database, and laboratory.Results: There were 108 suspected HIT cases in 2005. Thirty-one of the suspected HIT cases were treated: 12 out of 88 negative HIT cases, 7 out of 8 confirmed HIT cases, and all 12 confirmed HITT cases (Table). Six cases were treated with more than one HIT-safe anticoagulant (one negative HIT case and five confirmed HITT cases). Lepirudin accounted for 64% of the total HIT-safe medication costs in 2005. Overall, the direct thrombin inhibitors (DTIs) accounted for 96% of the treatment costs. Seventeen patients were treated with fondaparinux, eight of whom were negative HIT cases. Cases with confirmed HITT had greater treatment costs per patient than those with confirmed HIT. The average treatment cost of a negative HIT case was $64 ($0–$3,987).Conclusions: The treatment costs presented appear to be lower than costs presented in other studies. This may, in part, be the result of a hospital HIT management policy and a comprehensive TE Service that manages all cases of HIT. The total costs and the cost per patient were greatest for the DTIs.Table: HIT-safe anticoagulant use.Negative HITConfirmed HITConfirmed HITTTotal cost of useAverage argatroban cost ± SD (range)$3,987n = 1$0n = 0 n = 0$4,023 ± $4,211 ($693 – $8,757)n = 3$16,056Average bivalirudin cost ± SD (range)$0n = 0$9,302n = 1$0n = 0$9,302Average lepirudin cost ± SD (range)$221n = 1$3,562 ± $23 ($3,545 – $3,578)n = 2$4,793 ± $4,842 ($1,099 – $16,744)n = 9$50,482Average danaparoid cost ± SD (range)$228 ± $135 ($90 – $359)n = 3$0n = 0$54n = 1$738Average fondaparinux cost ± SD (range)$91 ± $58 ($28 – $196)n = 8$81 ± $67 ($42 – $182)n = 4$263 ± $100 ($140 – $365)n = 5$2,367Total number treated13172183NAAverage HIT-safe anticoagulant cost ± SD (range)$64 ± $428 ($0 – $3,987)Median = $0n = 88$2,094 ± $3,314 ($0 – $9,302)Median = $119n = 8$4,715 ± $4,776 ($252 – $16,744)Median = $3,156n = 12$78,945NA - not applicable, SD - standard deviation, 1One patient received both lepirudin and fondaparinux, 2 One patient died before receiving any treatment, 3 Five patients received more than one HIT-safe anticoagulant