A decision tree for differentiating tuberculous from malignant pleural effusions.
OBJECTIVE
To improve physicians' ability to discriminate tuberculous from malignant pleural effusions through a simple clinical algorithm that avoids pleural biopsy.


METHODS
We retrospectively compared the clinical and pleural fluid features of 238 adults with pleural effusion who satisfied diagnostic criteria for tuberculosis (n=64) or malignancy (n=174) at one academic center (derivation cohort). Then, we built a decision tree model to predict tuberculosis using the C4.5 algorithm. The model was validated with an independent sample set from another center that included 74 tuberculous and 293 malignant effusions (validation cohort).


RESULTS
Among 12 potential predictor variables, the classification tree analysis selected four discriminant parameters (age>35 years, pleural fluid adenosine deaminase>38U/L, temperature>or=37.8 degrees C, and pleural fluid LDH>320U/L) from the derivation cohort. The generated flowchart had 92.2% sensitivity, 98.3% specificity, and an area under the ROC curve of 0.976 for diagnosing tuberculosis. The corresponding operating characteristics for the validation cohort were 85.1%, 96.9% and 0.958.


CONCLUSIONS
Applying a decision tree analysis that contains simple clinical and laboratory data can help in the differential diagnosis of tuberculous and malignant pleural effusions.
Pleural Disease Unit, Department of Internal Medicine, Arnau de Vilanova University Hospital, IRBLLEIDA, Avda Alcalde Rovira Roure 80, 25198 Lleida, Spain. jporcelp@yahoo.es
José M
JM
Porcel
Carmen
C
Alemán
Silvia
S
Bielsa
Javier
J
Sarrapio
Tomás
T
Fernández de Sevilla
Aureli
A
Esquerda
D000243:Adenosine Deaminase / Q000032:analysis; D000328:Adult; D000367:Age Factors; D000368:Aged; D000465:Algorithms; D004796:Clinical Enzyme Tests / Q000379:methods; D003663:Decision Trees; D003937:Diagnosis, Differential; D005260:Female; D005334:Fever / Q000382:microbiology; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000032:analysis; D008297:Male; D008875:Middle Aged; D010996:Pleural Effusion / Q000737:chemistry / Q000382:microbiology / Q000473:pathology; D016066:Pleural Effusion, Malignant / Q000737:chemistry / Q000175:diagnosis* / Q000473:pathology; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014396:Tuberculosis, Pleural / Q000150:complications / Q000175:diagnosis*; D055815:Young Adult
D007770:L-Lactate Dehydrogenase; D000243:Adenosine Deaminase