title: International survey on D-dimer test reporting: a call for standardization.
abstract: D-dimer is the biochemical gold standard for diagnosing a variety of thrombotic disorders, but result reporting is heterogeneous in clinical laboratories. A specific five-item questionnaire was developed to gain a clear picture of the current standardization of D-dimer test results. The questionnaire was opened online (December 24, 2014-February 10, 2015) on the platform "Google Drive (Google Inc., Mountain View; CA)," and widely disseminated worldwide by newsletters and alerts. A total of 409 responses were obtained during the period of data capture, the largest of which were from Italy (136; 33%), Australia (55; 22%), Croatia (29; 7%), Serbia (26; 6%), and the United States (21; 5%). Most respondents belonged to laboratories in general hospitals (208; 51%), followed by laboratories in university hospitals (104; 26%), and the private sector (94; 23%). The majority of respondents (i.e., 246; 60%) indicated the use of fibrinogen equivalent unit for expressing D-dimer results, with significant heterogeneities across countries and health care settings. The highest prevalence of laboratories indicated they were using "ng/mL" (139; 34%), followed by "mg/L" (136; 33%), and "µg/L" (73; 18%), with significant heterogeneity across countries but not among different health care settings. Expectedly, the vast majority of laboratories (379; 93%) declared to be using a fixed cutoff rather than an age-adjusted threshold, with no significant heterogeneity across countries and health care settings. The results of this survey attest that at least 28 different combinations of measurement units are currently used to report D-dimer results worldwide, and this evidence underscores the urgent need for more effective international joined efforts aimed to promote a worldwide standardization of D-dimer results reporting.
authors.affiliation: Department of Clinical Chemistry and Hematology, Academic Hospital of Parma, Parma, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Lippi
authors.affiliation: Department of Clinical Sciences and Community Health, University of Milano, Italy.
authors.forename: Armando
authors.initials: A
authors.lastname: Tripodi
authors.affiliation: University Department of Chemistry, University Hospital Center Sestre Milosrdnice, Zagreb, Croatia.
authors.forename: Ana-Maria
authors.initials: AM
authors.lastname: Simundic
authors.affiliation: Department of Haematology, Institute of Clinical Pathology and Medical Research (ICPMR), Pathology West, NSW Health Pathology, Westmead, New South Wales, Australia.
authors.forename: Emmanuel J
authors.initials: EJ
authors.lastname: Favaloro
mesh_terms: D001774:Blood Chemical Analysis / Q000379:methods / Q000592:standards*; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis*; D005340:Fibrinogen / Q000737:chemistry; D006801:Humans; D007391:International Cooperation; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D013927:Thrombosis / Q000097:blood*; D014481:United States; D054556:Venous Thromboembolism / Q000097:blood
chemical_list: D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D; D005340:Fibrinogen