title: Screening of malignant pleural effusion by discriminant analysis.
abstract: OBJECTIVE
  To assess the value of discriminant analysis as a method of optimizing the discriminant power of routine parameters in differentiating between malignant and non-malignant pleural effusions.
  
  
  METHODS
  Retrospective review of the medical records of 245 patients with exudative pleural effusion.
  
  
  RESULTS
  The most powerful predictor of the malignant etiology of pleural effusion was a function that consisted of seven variables: age (years); effusion volume (coded as up to one third = 1, up to two thirds = 2, massive = 3); sedimentation rate (mm/h); monocyte count in the peripheral blood (cells/mm3); bloodstained exudate (coded as yes = 1, no = 2); and glucose (mg/dL) and iron (microg/dL) concentration in pleural fluid. This function showed a sensitivity of 77%, specificity of 85%, positive predictive value (PPV) of 76%, negative predictive value (NPV) of 86%, and was able to give an 82% rate of correct classification. In patients aged 50 years or younger, the NPV ranged between 91 and 98%, whereas in those older than 60 years, the PPV was 89%.
  
  
  CONCLUSIONS
  The calculated discriminant function is a simple, rapid, and inexpensive method for screening patients with pleural effusion for malignant etiology.
authors.affiliation: Service of Pneumology, Hospital Clinico Universitario, Valencia, Spain. fcava@eresmas.com
authors.forename: F
authors.initials: F
authors.lastname: Carrión-Valero
authors.forename: M
authors.initials: M
authors.lastname: Perpiñá-Tordera
authors.forename: J
authors.initials: J
authors.lastname: Sanchis-Aldás
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001799:Blood Sedimentation; D003937:Diagnosis, Differential; D016002:Discriminant Analysis; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening; D008499:Medical Records / Q000706:statistics & numerical data; D008875:Middle Aged; D010996:Pleural Effusion / Q000175:diagnosis*; D016066:Pleural Effusion, Malignant / Q000175:diagnosis*; D011237:Predictive Value of Tests; D012189:Retrospective Studies