title: Diagnostic strategy using a modified clinical decision rule and D-dimer test to rule out pulmonary embolism in elderly in- and outpatients.
abstract: Excluding or confirming pulmonary embolism remains a diagnostic challenge. In elderly patients pulmonary embolism is associated with substantial co-morbidity and mortality, and many elderly patients with suspected pulmonary embolism are inpatients. The safety and efficacy of the combination of a clinical probability (CDR) and d-dimer test in excluding pulmonary embolism in this group is unclear. We retrospectively analysed data of two prospective studies of consecutive in-and outpatients with suspected pulmonary embolism. The patients were categorized into three age groups: <65 years, 65-75 years and >75 years. The sensitivity, negative predictive value and the proportion of patients with the combination of a non-high CDR score according to Wells (< or = 4) and a normal d-dimer result were calculated for each group. In 747 consecutive patients with suspected pulmonary embolism, sensitivity and negative predictive value of a non-high CDR and a normal d-dimer result in outpatients (n=538) of all age categories (<65 years, 65-75 years and >75 years) were both 100%. These tests were, however, less reliable for inpatients(n=209), irrespective of their age (sensitivity 91% [ CI: 79-98%], negative predictive value 88 % [CI: 74-96%]. The proportion of both in-and outpatients >75 years with a non-high CDR and a normal d-dimer concentration was only 14%, whereas this was 22% in patients 65-75 years and 41% among in-and outpatients <65 years, respectively. In elderly outpatients the combination of a non-high CDR and a normal d-dimer result is a safe strategy to rule out pulmonary embolism. However, in inpatients this algorithm is not reliable to safely exclude pulmonary embolism. In addition, the proportion of patients >65 years in which this strategy excludes pulmonary embolism is markedly lower compared to younger patients.
authors.affiliation: Academic Medical Center, Department of Vascular Medicine, Room F4-136, Meibergdreef 9, 1105 AZ Amsterdam. m.sohne@amc.uva.nl
authors.forename: Maaike
authors.initials: M
authors.lastname: Söhne
authors.forename: Pieter W
authors.initials: PW
authors.lastname: Kamphuisen
authors.forename: Patricia J W B
authors.initials: PJ
authors.lastname: van Mierlo
authors.forename: Harry R
authors.initials: HR
authors.lastname: Büller
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001780:Blood Coagulation Tests; D003937:Diagnosis, Differential; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis* / Q000096:biosynthesis; D005853:Geriatrics / Q000379:methods*; D006801:Humans; D007297:Inpatients; D008875:Middle Aged; D010045:Outpatients; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011655:Pulmonary Embolism / Q000175:diagnosis*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
chemical_list: D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D