title: Practical utility of clinical prediction rules for suspected acute pulmonary embolism in a large academic institution.
abstract: BACKGROUND
  In an attempt to standardize clinicians' approach to the determination of pretest probability (PTP) in pulmonary embolism (PE), two simplified scoring models have recently been proposed. We sought to determine the utility of these algorithms in patients with suspected PE in a large, tertiary, academic medical center.
  
  
  METHODS
  We performed a retrospective analysis of 295 inpatients and outpatients from our institution who were evaluated for suspected PE. Pretest probability (PTP) was calculated using two previously formulated scoring systems by Wells et al. (Canadian score) and Wicki et al. (Geneva score). Our primary endpoint was the prevalence of PE within each strata of PTP.
  
  
  RESULTS
  The prevalence of pulmonary embolism in our cohort was 30%. The prevalence of PE in the low, intermediate and high PTP groups using the Canadian score was 15.3% (95% CI 9.5-23.7%), 34.8% (95% CI 27.9-42.4%), and 47.2% (95% CI 32.0-63.0), respectively. When compared with the low PTP group, the odds ratios of the likelihood of PE was 2.95 (95% CI 1.56-5.59) in the intermediate PTP group and 4.95 (95% CI 2.11-11.64) in the high PTP. The Wicki analysis was divided into "Geneva pure" and "Geneva presumed", where the fractional inspired oxygen concentration was known and presumed to have been sampled on room air, respectively. Neither of the Geneva scores showed statistical significance in the prevalence of PE among the PTP groups.
  
  
  CONCLUSIONS
  The Wells' clinical prediction score is easily applied and meaningfully risk stratifies patients with suspected PE. In our population, the Geneva score was less useful.
authors.affiliation: Pulmonary and Critical Care Medicine Service, Walter Reed Army Medical Center, Building 2, WD 77, 6900 Georgia Avenue NW, Washington, DC 20307-5001, USA. Lisa.Moores@na.amedd.army.mil
authors.forename: Lisa K
authors.initials: LK
authors.lastname: Moores
authors.forename: Jacob F
authors.initials: JF
authors.lastname: Collen
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Woods
authors.forename: Andrew F
authors.initials: AF
authors.lastname: Shorr
mesh_terms: D000046:Academic Medical Centers / Q000706:statistics & numerical data; D000208:Acute Disease; D000465:Algorithms; D015331:Cohort Studies; D003661:Decision Support Techniques; D003937:Diagnosis, Differential; D004219:District of Columbia / Q000453:epidemiology; D005260:Female; D006772:Hospitals, Military / Q000706:statistics & numerical data; D006801:Humans; D016013:Likelihood Functions; D008297:Male; D008396:Maryland / Q000453:epidemiology; D008875:Middle Aged; D016017:Odds Ratio; D011237:Predictive Value of Tests; D015995:Prevalence; D011655:Pulmonary Embolism / Q000175:diagnosis* / Q000453:epidemiology*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D014768:Virginia / Q000453:epidemiology