title: Limitations of D-dimer testing in unselected inpatients with suspected venous thromboembolism.
abstract: OBJECTIVE
  To determine the utility and limitations of D-dimer testing for the evaluation of venous thromboembolism in hospitalized patients.
  
  
  METHODS
  We performed D-dimer testing by four different methods in unselected inpatients undergoing radiologic evaluation for possible venous thromboembolism. We included patients with a history of malignancy, recent surgery, thrombosis, and anticoagulation treatment. C-reactive protein levels were assayed as a measure of inflammation.
  
  
  RESULTS
  Of 45 patients with radiographically proven proximal deep venous thrombosis or pulmonary embolism, 43 had elevated D-dimer levels by enzyme-linked immunosorbent assay (ELISA) (sensitivity, 96%); the specificity of the test was 23% (36/157). The qualitative non-ELISA tests had higher specificities, but their sensitivities were <70%. Nineteen patients (42%) with thrombosis had false-negative D-dimer tests by at least one assay. The specificity of the tests decreased with increasing duration of hospitalization, increasing age, and increasing C-reactive protein levels. D-dimer testing had little or no utility in distinguishing patients with thrombosis from those without in patients who had been hospitalized for more than 3 days, were older than 60 years, or had C-reactive protein levels in the highest quartile.
  
  
  CONCLUSIONS
  In unselected inpatients, D-dimer testing has limited clinical utility because of its poor specificity. This is particularly true for older patients, those who have undergone prolonged hospitalization, and those with markedly elevated C-reactive protein levels. In some patient subsets, a negative non-ELISA D-dimer test cannot discriminate between inpatients with and without thrombosis.
authors.affiliation: Department of Medicine, Johns Hopkins Hospital, Baltimore, Maryland, USA. brotmad@ccf.org
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Brotman
authors.forename: Jodi B
authors.initials: JB
authors.lastname: Segal
authors.forename: Jayesh T
authors.initials: JT
authors.lastname: Jani
authors.forename: Brent G
authors.initials: BG
authors.lastname: Petty
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Kickler
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000372:Agglutination Tests; D015415:Biomarkers / Q000032:analysis; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis / Q000378:metabolism*; D006801:Humans; D007297:Inpatients; D007841:Latex Fixation Tests; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D011655:Pulmonary Embolism / Q000097:blood* / Q000000981:diagnostic imaging / Q000628:therapy; D012372:ROC Curve; D011859:Radiography; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D020246:Venous Thrombosis / Q000097:blood* / Q000000981:diagnostic imaging / Q000628:therapy
chemical_list: D015415:Biomarkers; D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D