Predictor variable

Unstandardized coefficient β

Standard error

Standardization coefficient Beta

t

p

(Constant)

74.16

4.42

16.77

0.00

Place of residence

0.70

0.87

0.08

0.80

0.42

Education level

−1.02

0.47

−0.22

−2.17

0.03

Occupation

0.08

0.18

0.03

0.42

0.68

Monthly personal income

−1.38

0.42

−0.32

−3.3

0.00

Health status of main caregivers

1.05

0.93

0.08

1.12

0.26

Smoking history

4.25

2.02

0.26

2.10

0.04

Number of cigarettes smoked per day

−0.48

1.16

−0.04

−0.41

0.68

Years of smoking

−0.05

1.03

−0.01

−0.05

0.96

Postoperative treatment or not

1.82

1.03

0.13

1.76

0.08