title: Accuracy of the Wells clinical prediction rule for pulmonary embolism in older ambulatory adults.
abstract: OBJECTIVE
  To determine whether the Wells clinical prediction rule for pulmonary embolism (PE), which produces a point score based on clinical features and the likelihood of diagnoses other than PE, combined with normal D-dimer testing can be used to exclude PE in older unhospitalized adults.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Primary care and nursing homes.
  
  
  METHODS
  Older adults (≥60) clinically suspected of having a PE (N = 294, mean age 76, 44% residing in a nursing home).
  
  
  METHODS
  The presence of PE was confirmed using a composite reference standard including computed tomography and 3-month follow-up. The proportion of individuals with an unlikely risk of PE was calculated according to the Wells rule (≤4 points) plus a normal qualitative point-of-care D-dimer test (efficiency) and the presence of symptomatic PE during 3 months of follow-up within these patients (failure rate).
  
  
  RESULTS
  Pulmonary embolism occurred in 83 participants (28%). Eighty-five participants had an unlikely risk according to the Wells rule and a normal D-dimer test (efficiency 29%), five of whom experienced a nonfatal PE during 3 months of follow-up (failure rate = 5.9%, 95% confidence interval (CI) = 2.5-13%). According to a refitted diagnostic strategy for older adults, 69 had a low risk of PE (24%), two of whom had PE (failure rate = 2.9%, 95% CI = 0.8-10%).
  
  
  CONCLUSIONS
  The use of the well-known and widely used Wells rule (original or refitted) does not guarantee safe exclusion of PE in older unhospitalized adults with suspected PE. This may lead to discussion among professionals as to whether the original or revised Wells rule is useful for elderly outpatients.
authors.affiliation: Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, the Netherlands; Department of Geriatrics, University Medical Center Utrecht, Utrecht, the Netherlands.
authors.forename: Henrike J
authors.initials: HJ
authors.lastname: Schouten
authors.forename: Geert-Jan
authors.initials: GJ
authors.lastname: Geersing
authors.forename: Ruud
authors.initials: R
authors.lastname: Oudega
authors.forename: Johannes J M
authors.initials: JJ
authors.lastname: van Delden
authors.forename: Karel G M
authors.initials: KG
authors.lastname: Moons
authors.forename: Huiberdina L
authors.initials: HL
authors.lastname: Koek
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000553:Ambulatory Care; D002423:Cause of Death; D015331:Cohort Studies; D003661:Decision Support Techniques; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis; D005500:Follow-Up Studies; D006707:Homes for the Aged; D006801:Humans; D016013:Likelihood Functions; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D009735:Nursing Homes; D011237:Predictive Value of Tests; D011320:Primary Health Care; D011446:Prospective Studies; D011655:Pulmonary Embolism / Q000097:blood / Q000175:diagnosis* / Q000401:mortality; D014057:Tomography, X-Ray Computed; D054556:Venous Thromboembolism / Q000097:blood / Q000175:diagnosis / Q000401:mortality
chemical_list: D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D
keywords: D-dimer; Wells; clinical decision rule; diagnosis; elderly; geriatric; nursing home; pulmonary embolism; venous thromboembolism