Characteristics

N

COHb (%)

Mean ± SD

Statistics

Coefficient

P-Value

Duration of Smoking Habit

<5 years

≥5 years

21

9

15.69 ± 8.43

16.16 ± 9.27

t, 0.136

0.893

Frequency of Smoking

Always

Occasionally

Rarely

4

11

15

27.10 ± 3.21

15.63 ± 10.55*

12.97 ± 4.88*

F, 5.76

0.008

Smoking Intensity

<5 sticks per day

≥5 sticks per day

28

2

15.35 ± 8.62

22.54 ± 3.03

t, −1.16

0.256