PSQI (n = 226)

Χ² value

φ

P value

PSQI ≥ 6

PSQI < 6

(n = 8)

(n = 218)

n

%

Adjusted residual

n

%

Adjusted residual

Breakfast

(n = 226)

I eat breakfast every morning.

6

2.65

−1.6

199

88.05

1.6

0.88

−0.10

0.16

I sometimes do not eat breakfast.

2

0.88

1.6

19

8.41

−1.6

Bowel movement

(n = 226)

I have bowel movement every day.

4

1.77

−0.5

130

57.52

0.5

0.03

−0.04

0.72

I do not have bowel movement every day.

4

1.77

0.5

88

38.94

−0.5

School meal

(n = 226)

I always eat a full school meal.

5

2.21

0.0

136

60.18

0.0

0.00

0.00

1.00

I sometimes leave part of a school meal.

3

1.33

0.0

82

36.28

0.0

Snack (lunch to dinner)

(n = 226)

I eat a snack four days or more a week.

4

1.77

0.7

82

36.28

−0.7

0.11

0.05

0.48

I eat a snack less than three days a week.

4

1.77

−0.7

136

60.18

0.7

Snack (dinner to fall asleep)

(n = 226)

I eat a snack four days or more a week.

1

0.44

0.6

15

6.64

−0.6

0.00

0.04

0.45

I eat a snack less than three days a week.

7

3.10

−0.6

203

89.82

0.6

Exercise

(n = 226)

I exercise three or more days a week.

6

2.65

−0.2

170

75.22

0.2

0.00

−0.01

1.00

I exercise less than two days a week.

2

0.88

0.2

48

21.24

−0.2

Cram school

(n = 226)

I am going to cram school.

5

2.21

0.9

101

44.69

−0.9

0.29

0.06

0.48

I am not going to cram school.

3

1.33

−0.9

117

51.77

0.9

Physical strength

(n = 225)

High

2

0.89

1.6

117

52.00

−1.6

1.56

0.11

0.15

Low

6

2.67

−1.6

100

44.44

1.6

Falling asleep*

(n = 177)

I could fall asleep quickly.

1

0.56

−2.7

152

85.88

2.7

3.46

−0.20

0.05

I had difficulty sleeping.

2

1.13

2.7

22

12.43

−2.7

Wake up**

(n = 105)

I woke up feeling refreshed.

2

1.90

−2.0

79

75.24

2.0

2.19

−0.20

0.08

I was sleepy.

3

2.86

2.0

21

20.00

−2.0