title: Wells Score and Poor Outcomes Among Adult Patients With Subsegmental Pulmonary Embolism: A Cohort Study.
abstract: BACKGROUND
  Since the introduction of computed tomography pulmonary angiography, isolated subsegmental pulmonary embolism has become a commonly recognized clinical problem, but its clinical relevance remains unclear. The objective of the present study was to evaluate the extent to which the simplified Wells score discriminates between patients with varying levels of risk of complications after presenting with subsegmental pulmonary embolism.
  
  
  METHODS
  Retrospective cohort study. Patients included had subsegmental pulmonary embolism (1 or multiple emboli limited to subsegmental arteries). Primary explanatory variable was the simplified Wells score, categorized as high (>4) or low (≤4). The primary outcome was time to death or new venous thromboembolism. Kaplan-Meier techniques and Cox regression analysis were used to compare the survival experience of patients with high versus low Wells score with and without adjustment for active malignancy, age, Charlson score, previous venous thromboembolism, and previous major surgery in the last 30 days.
  
  
  RESULTS
  Seventy-nine patients with subsegmental pulmonary embolism were included. Patients with a high Wells score had a 4-fold increased risk of the composite outcome (hazard ratio = 4.2, 95% confidence interval [CI] = 2.0-8.9, P < .001). Other covariates significantly associated with increased risk in univariate analyses included active malignancy, a low serum albumin, and an increased Charlson score. In multivariate Cox regression analyses adjusting for these other factors, a high Wells score remained significant (hazard ratio 5.5, 95% CI 2.4-12.6, P < .001).
  
  
  CONCLUSIONS
  High Wells score is associated with death or new venous thromboembolism during follow-up among patients with subsegmental pulmonary embolism.
  
  
  BACKGROUND
  ClinicalTrials.gov number, NCT01372514.
authors.affiliation: Internal Medicine Department, Hospital Italiano de Buenos Aires, Buenos Aires University, Buenos Aires, Argentina federico.angriman@hospitalitaliano.org.ar.
authors.forename: Federico
authors.initials: F
authors.lastname: Angriman
authors.affiliation: Internal Medicine Department, Hospital Italiano de Buenos Aires, Buenos Aires University, Buenos Aires, Argentina.
authors.forename: Bruno L
authors.initials: BL
authors.lastname: Ferreyro
authors.affiliation: Internal Medicine Research Unit, Hospital Italiano de Buenos Aires, Buenos Aires, Argentina.
authors.forename: María L
authors.initials: ML
authors.lastname: Posadas-Martinez
authors.affiliation: Internal Medicine Research Unit, Hospital Italiano de Buenos Aires, Buenos Aires, Argentina.
authors.forename: Diego
authors.initials: D
authors.lastname: Giunta
authors.affiliation: Internal Medicine Department, Hospital Italiano de Buenos Aires, Buenos Aires, Argentina.
authors.forename: Fernando J
authors.initials: FJ
authors.lastname: Vazquez
authors.affiliation: Kaiser Permanente Center for Health Research, Portland, OR, USA.
authors.forename: William M
authors.initials: WM
authors.lastname: Vollmer
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging* / Q000401:mortality*; D012189:Retrospective Studies; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed / Q000379:methods
keywords: pulmonary embolism; risk factors; subsegmental