Table 3 Factor structure of WorkTime Scale survey items in 3 blue-collar worker samples

Q1

I worked more than 12 hours per day

0.75

0.63

0.70

Q2

I worked more than 48 hours per week

0.83

0.69

0.75

Q3

I worked overtime

0.53

0.58

0.58

Q4

I worked some early morning hours between 5 am and 8 am

0.84

0.07 ns

0.24

Q5

I worked at least 3 daytime hours between 8 am and 6 pm

–

–

–

–

–

–

Q6

I worked at least 3 evening hours after 6 pm

0.81

0.64

0.72

Q7

I worked at least 3 overnight hours between 11 pm and 5 am

0.80

0.45

0.52

Q8

I worked 6 or more days in a row

0.80

0.77

0.77

Q9

I had two or more days off in a row

–

–

–

–

–

–

Q10

I had less than 11 hours between shifts

–

–

–

–

–

–

Q11

I was on call (expected to immediately provide work or service if contacted or called)

0.61

0.67

0.85

Q12

I worked mandatory overtime

0.58

0.54

0.65

Q13

I had control over my work schedule

–

–

–

–

–

–

Q14

I had to go to work unexpectedly at times when I was not scheduled to work

0.95

0.85

0.77

Q15

I unexpectedly had to work more than an hour later than I was scheduled to work

0.60

0.71

0.73

Q16

I knew my schedule in advance

–

–

–

–

–

–

Q17

Last minute adjustments were made to my schedule

–

–

–

–

–

–

Q18

I worked on a Sunday

0.88

0.86

0.86

Q19

I worked on the weekend

0.87

0.89

0.85

Q20

I worked on a holiday

0.81

0.94

0.82

Q21

I worked during a special event (e.g., birthday party, wedding, graduation party, etc.)

–

–

–

–

–

–

0.95

0.87

0.88

0.76

0.88

0.81