Study population

Spirometry Test

Taxi drivers’ smokers

Taxi drivers non-smoker

Employees smokers

Employees non-smokers

P-Value

Participants/n

140

60

90

30

FEV1 (%)

average^*

79.55

80.32

83.88

91.64

< 0.05

FEV1/FVC average^*

0.78

0.81

0.84

0.86

< 0.05

Mean symptoms score^*

46.5

31.1

23.7

17.4

0.006