Assessing the clinical and cost impact of on-demand immunoassay testing for the diagnosis of heparin induced thrombocytopenia

- Testing on-demand enables treatment decisions to be based on test results.
- Testing on-demand with fast turnaround enables rapid treatment decisions.
- Testing on-demand reduces the cost of speculatively switching patients off heparin.
- Testing on-demand may reduce clinical outcomes representing HIT complications.

BackgroundThe diagnostic work-up for heparin induced thrombocytopenia (HIT) can take several days. Consequently patients may be speculatively switched onto replacement anticoagulant therapy before a diagnosis is confirmed. On-demand immunoassay diagnostic testing enables timely treatment decisions, based on test results.ObjectiveTo estimate the clinical and cost impact of the use of on-demand versus batched diagnostic tests for HIT.MethodsLiterature was reviewed to identify test performance, clinical and cost data. Semi-structured interviews (n = 4) and a survey (n = 90) provided insights into current practice and challenges. Flow diagram models were developed to estimate the potential impact of on-demand testing.ResultsModelling estimated more HIT-related outcomes for patients maintained on heparin whilst awaiting test results and patients switched onto replacement anticoagulant therapy awaiting test results, compared with on-demand testing and treatment based on the results. The budget impact model estimated that on-demand testing reduced replacement anticoagulant therapy costs from $39,616 to $12,799 per patient. There are limitations to the data available to inform modelling and the estimates should be treated with caution.ConclusionsUsing on-demand testing may drive positive effects on clinical and cost outcomes.