title: C-reactive protein and D-dimer with clinical probability score in the exclusion of pulmonary embolism.
abstract: This study evaluated the diagnostic value of C-reactive protein (CRP) combined with a clinical decision rule in the exclusion of pulmonary embolism (PE) and compared this with D-dimer. In 363 consecutive outpatients CRP and D-dimer test were performed and clinical probability of PE was assessed. Patients with D-dimer levels<500 microg/l and clinical probability indicating 'PE unlikely' were followed for 3 months. Ventilation-perfusion scan or spiral computerized tomography was performed in patients with D-dimer levels>or=500 microg/l or clinical probability indicating 'PE likely'. The CRP had a sensitivity of 95.7% [95% confidence interval (CI): 90-100] and negative predictive value (NPV) of 98.4% (96-100). CRP<5 mg/l with clinical probability score indicating 'PE unlikely' (n=108, 30%), had a sensitivity of 96.7% (90-100), a specificity of 43.0% (37-49) and NPV of 99.1% (97-100). D-dimer<500 microg/l with clinical probability score indicating 'PE unlikely' (n=170, 51%), had a sensitivity of 96.7% (90-100), a specificity of 67.9% (62-74) and NPV of 99.4% (98-100). Based on retrospective data it was concluded that a standard CRP test can potentially be used to safely exclude PE, either as a sole test or combined with clinical probability assessment. Prospective studies are needed to confirm these findings.
authors.affiliation: Department of General Internal Medicine, Leiden University Medical Centre, Leiden, the Netherlands. n.steeghs@lumc.nl
authors.forename: N
authors.initials: N
authors.lastname: Steeghs
authors.forename: R J
authors.initials: RJ
authors.lastname: Goekoop
authors.forename: R W L M
authors.initials: RW
authors.lastname: Niessen
authors.forename: G J P M
authors.initials: GJ
authors.lastname: Jonkers
authors.forename: H
authors.initials: H
authors.lastname: Dik
authors.forename: M V
authors.initials: MV
authors.lastname: Huisman
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis*; D016001:Confidence Intervals; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis*; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011336:Probability; D011446:Prospective Studies; D011655:Pulmonary Embolism / Q000097:blood / Q000175:diagnosis*; D012372:ROC Curve; D012189:Retrospective Studies; D012307:Risk Factors; D012680:Sensitivity and Specificity
chemical_list: D015415:Biomarkers; D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D; D002097:C-Reactive Protein