Demographic and clinical characteristics of the subjects in derivation phase and validation phase.

G1, patients with culture-positive PTB in derivation group; G2, patients other pulmonary diseases in the derivation group; G3, patients with culture-positive PTB in validation group; G4, patients other pulmonary diseases in the validation group.Data are presented as mean ± standard deviation for continuous variables, and n (%) for categorical variables.PTB, pulmonary tuberculosis; NA, not assessed.*Indicates statistical significance between G1 and G2 in derivation phase or between G3 and G4 in validation phase, P§Comparision of the incidence of culture-positive PTB of the derivation group with the validation group (3.2% [132/4140] vs. 3.6% [147/4105], P = 0.654).Note: Combined disease such as bacterial infection with culture-positive PTB (n = 1), and lymphoma with culture-positive PTB (n = 1) were grouped as culture-positive PTB. In the derivation phase there were 633 patients with previous PTB (19 with culture-positive PTB and 614 other pulmonary diseases without culture-positive PTB).