Fig 4. Positive (PPV) and negative (NPV) predictive values of five tests used to diagnose pulmonary tuberculosis in 344 captive bears in Cambodia and Vietnam.

Tests included thoracic radiography, serology (DPP VetTB assay, with two definitions of positive depending on the strength of the reaction line), and microscopy, PCR, and culture of bronchoalveolar lavage (BAL) samples. Median (points) and 95% Bayesian credible intervals (bars) are shown for estimates calculated for two disease prevalence scenarios using a Bayesian latent class model assuming conditional dependence between BAL microscopy and BAL PCR.