A two-stage thrombophilia screening protocol: more efficient use of laboratory tests

Abstract number: P0334

Leyte^* A., Van Zanten† A. P., Van Der Heide† Y. T., Smits† P. H. M., ten cate† H., Brandjes† D. P. M.

^*Onze Lieve Vrouwe Gasthuis, HKCL, Netherlands; †Slotervaart Hospital, Netherlands

In an emergency room setting, on clinical wards and in the out-patient clinic, the diagnosis of venous thromboembolism (VTE) is often considered. In the majority of cases however, it is subsequently rejected as soon as the results of objective investigations are available. So far, optimalization of laboratory testing in VTE has been mostly restricted to the diagnostic strategies for its exclusion and confirmation. The fact that often, in putative VTE cases, extensive laboratory testing for VTE risk factors (a thrombophilia screen) is triggered in an early stage has received less attention. Even though this screen is not meaningful if VTE is later rejected, it is more often than not carried out anyway once it has been ordered, nullifying part of the savings obtained by diagnostic optimalization. In the Slotervaart Hospital in 1999 this has led to the implementation of a joint thrombophilia screening protocol for the Department of Internal Medicine and the Clinical Chemistry and Hematology Laboratory with the purpose of only performing comprehensive VTE risk factor testing if the presence of VTE has been confirmed objectively. A second goal was to prevent incomplete or redundant lab work and to facilitate data-analysis by adopting a fixed test profile. In total, 236 patients were included in this protocol in 2.5 years of time. Of these, 95 patients (40%) proved to be eligible for a full thrombophilia screen. This yielded impressive savings on test costs, provided information on the prevalence of (double and triple) risk factors in the population investigated, and therefore provided tools for further streamlining of the protocol.