title: Use of likelihood ratios improves interpretation of laboratory testing for pulmonary sarcoidosis.
abstract: Laboratory tests for pulmonary sarcoidosis (percentage lymphocytes and CD4/CD8 ratio in bronchoalveolar lavage fluid and serum angiotensin-converting enzyme activity) lack sensitivity and specificity. In a retrospective study of 153 subjects under suspicion of pulmonary sarcoidosis (36 cases and 117 patients with other diseases [control patients]), we defined likelihood ratios (LRs) for rationally selected result intervals of these tests, which improve clinical interpretation as compared with dichotomous interpretation based on a single cutoff value. By using logistic regression analysis, we further integrated the 3 individual tests into a unified algorithm that could rule out diagnosis in 57 (48.7%) of the 177 control subjects and confirm diagnosis in 12 (33%) of the 36 pulmonary sarcoidosis cases. We conclude that use of LRs improves interpretation of laboratory tests for pulmonary sarcoidosis. In addition, we present a prediction algorithm based on the combination of laboratory tests that helps clinicians confirm or exclude diagnosis in almost half of the study population.
authors.affiliation: Dept of Haematology, Universitair Ziekenhuis Brussel, Laarbeeklaan 101, Brussels, Belgium.
authors.forename: Dieter
authors.initials: D
authors.lastname: De Smet
authors.forename: Geert A
authors.initials: GA
authors.lastname: Martens
authors.forename: Bram Vanden
authors.initials: BV
authors.lastname: Berghe
authors.forename: Marc
authors.initials: M
authors.lastname: Meysman
authors.forename: Olivier
authors.initials: O
authors.lastname: Heylen
authors.forename: Frans K
authors.initials: FK
authors.lastname: Gorus
authors.forename: Marc
authors.initials: M
authors.lastname: De Waele
mesh_terms: D000465:Algorithms; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry / Q000166:cytology; D016516:CD4-CD8 Ratio / Q000706:statistics & numerical data; D019411:Clinical Laboratory Techniques / Q000379:methods / Q000592:standards / Q000706:statistics & numerical data*; D003627:Data Interpretation, Statistical; D005260:Female; D006801:Humans; D016013:Likelihood Functions; D016015:Logistic Models; D008297:Male; D012189:Retrospective Studies; D017565:Sarcoidosis, Pulmonary / Q000097:blood / Q000175:diagnosis*