Table 4 Utility of each attribute level and the result of logit analysis (N = 220)

Working mode

 Part-time work

6.99

0.05

0.03

0.08

Reference

 Full-time work

-6.99

-0.05

0.03

0.08

0.90

(0.86–0.96)

Duration per visit

 1 h

41.05

0.29

0.06

< 0.001

Reference

 2 h

19.10

0.14

0.06

0.01

0.85

(0.77–0.95)

 3 h

-4.91

-0.04

0.05

0.51

0.72

(0.65–0.80)

 4 h

-55.24

-0.40

0.06

< 0.001

0.50

(0.45–0.56)

Income per visit(¥)^a

 100

-139.00

-0.99

0.06

< 0.001

Reference

 250

-20.12

-0.14

0.05

0.007

2.34

(2.11–2.60)

 400

46.53

0.33

0.05

< 0.001

3.77

(3.39–4.19)

 550

112.59

0.81

0.06

< 0.001

6.05

(5.41–6.75)

Personal safety management

 Superior

78.56

0.56

0.05

< 0.001

Reference

 Medium

4.88

0.03

0.05

0.44

0.59

(0.54–0.64)

 Basic

-83.44

-0.60

0.05

< 0.001

0.31

(0.29–0.35)

Medical risk prevention

 Superior

30.15

0.22

0.04

< 0.001

Reference

 Medium

0.66

0.01

0.05

0.92

0.81

(0.74–0.88)

 Basic

-30.81

-0.22

0.04

< 0.001

0.65

(0.59–0.71)

Refresher training

 Less than 4 h

-6.44

-0.05

0.04

0.30

Reference

 4 − 8 h

-2.30

-0.02

0.05

0.72

1.03

(0.94–1.13)

 More than 8 h

8.75

0.06

0.04

0.16

1.11

(1.02–1.22)