title: Performance of the Wells score in patients with suspected pulmonary embolism during hospitalization: a delayed-type cross sectional study in a community hospital.
abstract: BACKGROUND
  The role of the Wells score for patients who develop signs and symptoms of pulmonary embolism (PE) during hospitalization has not been sufficiently validated. The aim of this study is to evaluate the performance of the Wells score for inpatients with suspected PE and to evaluate the prevalence of pulmonary embolism.
  
  
  METHODS
  We conducted a cross sectional study nested in the prospective Institutional Registry of Thromboembolic Disease at Hospital Italiano de Buenos Aires from June 2006 to March 2011. We included patients who developed symptoms of pulmonary embolism during hospitalization. Patients were stratified based on the Wells score as PE likely (>4 points) or PE unlikely (≤4 points). The presence of pulmonary embolism was defined by pre-specified criteria.
  
  
  RESULTS
  Six hundred and thirteen patients met the inclusion criteria, with an overall prevalence of PE of 36%. Two hundred and nineteen (34%) were classified as PE likely and 394 (66%) as PE unlikely with a prevalence of PE of 66% and 20%, respectively. The Wells score showed a sensitivity of 65 (95% CI 59-72), specificity 81 (95% CI 77-85), positive predictive value 66 (95% CI 60-72) and negative predictive value 80 (95% CI 77-84).
  
  
  CONCLUSIONS
  The Wells Score is accurate to predict the probability of PE in hospitalized patients and this population had a higher prevalence of PE than other cohorts. However, the score is not sufficiently predictive to rule out a potentially fatal disorder.
authors.affiliation: Internal Medicine Research Unit, Internal Medicine Department, Hospital Italiano de Buenos Aires, Buenos Aires, Argentina. Electronic address: maria.posadas@hospitalitaliano.org.ar.
authors.forename: María Lourdes
authors.initials: ML
authors.lastname: Posadas-Martínez
authors.affiliation: Internal Medicine Department, Hospital Italiano de Buenos Aires, Buenos Aires, Argentina. Electronic address: fernando.vazquez@hospitalitaliano.org.ar.
authors.forename: Fernando Javier
authors.initials: FJ
authors.lastname: Vázquez
authors.affiliation: Internal Medicine Research Unit, Internal Medicine Department, Hospital Italiano de Buenos Aires, Buenos Aires, Argentina. Electronic address: diego.giunta@hospitalitaliano.org.ar.
authors.forename: Diego Hernán
authors.initials: DH
authors.lastname: Giunta
authors.affiliation: Internal Medicine Department, Hospital Italiano de Buenos Aires, Buenos Aires, Argentina. Electronic address: gabriel.waisman@hospitalitaliano.org.ar.
authors.forename: Gabriel Darío
authors.initials: GD
authors.lastname: Waisman
authors.affiliation: Internal Medicine Research Unit, Internal Medicine Department, Hospital Italiano de Buenos Aires, Buenos Aires, Argentina. Electronic address: fernan.quiros@hospitalitaliano.org.ar.
authors.forename: Fernán González Bernaldo
authors.initials: FG
authors.lastname: de Quirós
authors.affiliation: Ottawa Hospital-Ottawa Hospital Research Institute, Otawa, Canada. Electronic address: egandara@ohri.ca.
authors.forename: Esteban
authors.initials: E
authors.lastname: Gándara
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001118:Argentina / Q000453:epidemiology; D003430:Cross-Sectional Studies; D005260:Female; D006760:Hospitalization; D006764:Hospitals, Community; D006801:Humans; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D015995:Prevalence; D011655:Pulmonary Embolism / Q000175:diagnosis* / Q000453:epidemiology*
keywords: %; AUC; Angio-CT scan; Area under the curve; BMI; CI; COPD; Chi(2); DVT; HIBA; HR; Hospital Italiano de Buenos Aires; IR; IRTD; Institutional Registry of Thromboembolic Disease; LR+; LR-; N; NPV; Negative likelihood ratio; Negative predictive value; OR; PE; PPV; Positive likelihood ratio; Positive predictive value; ROC; Reciever operating characteristics; UFH; US; VTE; Vs; Wks; angiography computed tomography scan; body mass index; chi-square test; chronic pulmonary disease; confidence interval; deep venous thrombosis; e.g; epidemiology; et al; et alia, Latin for "and others."; for example; heart rate; hospitalized patient; i.e; id est; interquartile range; min; minutes; no pulmonary embolism; no-PE; number; odds ratio; percentage; pulmonary embolism; risk stratification; scores; ultrasound; unfractioned heparin; venous thromboembolic disease; versus; weeks