Table 6 Descriptive Statistics of the Total Sample, Test of Gender Differences, Bivariate Correlations Between Individual ISI Items, and Item-Total Correlations Among Male and Female Adult Workers

Item 1

0.70

0.93

0-4

1.27

0.95

2.70

.005

Item 2

1.09

1.15

0-4

0.93

0.09

0.05

.000

---

---

Item 3

0.99

1.11

0-4

0.94

−0.01

0.40

.001

---

---

Item 4

1.41

1.07

0-4

0.55

−0.40

0.09

.000

---

---

Item 5

1.23

0.95

0-4

0.58

−0.18

0.34

.001

---

---

Item 6

0.89

0.92

0-4

0.80

−0.17

0.38

.001

---

---

Item 7

0.67

1.01

0-4

1.52

1.56

0.00

.000

---

---

ISI total score

6.98

4.96

0-26

1.02

0.92

0.01

.000

0.48

.030

Bivariate correlations

Item 1

Item 2

Item 3

Item 4

Item 5

Item 6

Item 7

Item 1

---

.40***

.32***

.51***

.20***

.12*

.49***

Item 2

.56***

---

.72***

.71***

.23***

.13*

.66***

Item 3

44***

.57***

---

.62***

.20***

.11*

.61***

Item 4

.63***

.73***

.51***

---

.19***

.06

.70***

Item 5

.20*

.15

.22*

.19*

---

.45***

.30***

Item 6

.12

.06

.05

.12

.41***

---

.27***

Item 7

.62***

.66***

.54***

.75***

.40***

.22*

---

r_it

.64***

.68***

.57***

.73***

.34***

.21*

.68***