Participants characteristics
TUBERCULOSIS (TB)
We interviewed 2,925 residents. Finally, 2,486 eligible participants were included in the analysis, of which 1,584 lived in low altitudes (mean: 1,190.56 m, range: 996–1,442 m) and 902 lived in high altitudes (mean: 2,684.92 m, range: 2,416–2,896 m). Compared to the low-altitude population, the high-altitude population showed significant differences in demographic characteristics except for body mass index (BMI), history of tuberculosis (TB), and coal as fuel (Demographic characteristics and exposures of Gansu participants aged 40 years or older.BMI, body-mass index; FVC, forced vital capacity; FEVMean (minimum, maximum).Mean (standard deviation, SD).Median (PLow altitudes vs. high altitudes.Five patients older than 81 years were excluded.Bold values denote significant 