title: Application of age-adjusted D-dimer threshold for exclusion thromboembolism (PTE) in older patients: a retrospective study.
abstract: The D-dimer assay's ability to exclude pulmonary thromboembolism (PTE) falls with age.1,2 Douma et al. have proposed an age-adjusted D-dimer threshold ([threshold, µg/l] = [age, years] x 10) for patients aged >50 years with low clinical risk of PTE.3 We retrospectively applied this threshold to patients who underwent computer tomographic pulmonary angiogram (CTPA) for suspected PTE during a 13 month period at a busy District General Hospital. Of the 423 patients >50 years old who underwent CTPA, 22 (5.2%) had D-dimer concentrations higher than the traditional threshold but lower than the age-adjust threshold, none of whom had evidence of PTE on CTPA. This suggests that use of the age-adjusted D-dimer threshold may reduce necessity for CTPA concept patients aged >50 years.
authors.affiliation: Foundation Year 2 Doctor, Southern General Hospital,NHS Greater Glasgow and Clyde. owainleng@hotmail.com
authors.forename: O
authors.initials: O
authors.lastname: Leng
authors.forename: H B
authors.initials: HB
authors.lastname: Sitaraaman
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography / Q000379:methods; D015415:Biomarkers / Q000097:blood; D015331:Cohort Studies; D003937:Diagnosis, Differential; D004056:Differential Threshold; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis*; D006769:Hospitals, General; D006801:Humans; D008297:Male; D008875:Middle Aged; D011655:Pulmonary Embolism / Q000097:blood* / Q000000981:diagnostic imaging*; D012372:ROC Curve; D012189:Retrospective Studies; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013923:Thromboembolism / Q000097:blood / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed / Q000379:methods
chemical_list: D015415:Biomarkers; D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D