| Author, Date |
Sample |
Measure of Overtime |
Health or Safety Measure |
Statistical Methods Controls |
Results Reported by Authors |
| Kageyama et al.1998 |
233 male white collar workers:
- Age M 30.8
- Japan |
One-time questionnaire and interview (overtime h/month < 20; 20 - 59; >60) |
One-time questionnaire and interview measured exercise: rarely, 1-2/month, 1 wk, >= 2/wk |
- General linear models
- Covariates: age, body mass index, smoking and alcohol intake, commute time
- Kendall's rank correlation |
Frequency of exercise not correlated with overtime |
| Kirkcaldy et al. 1997 |
2,500 healthcare workers:
- Women 87%
- Age M 33, R 15 - 86
- Germany |
One-time questionnaire: work h/wk |
One-time questionnaire: driving crashes and job-related "accidents" |
- Multiple regression
- Covariates: age, gender, work climate, commute distance, job stress, children |
As work hours increased, job-related "accidents" and driving crashes increased (p < .05) |
| Mizoue et al. 2001a |
1,281 municipal employees:
- Age not reported
- Men 72%
- Japan |
One-time questionnaire (overtime hours during previous month 0 - < 10; 10<30; >=30) |
One-time questionnaire:
- Sick building syndrome symptoms
- Environmental tobacco smoke (ETS) |
- Multivariate logistic regression
- Covariates: age, gender, position type, asthma or hay fever, VDT use, work interest, work overload, work control, colleague support, distress, sports activity, sleep hours |
- Percent of workers active in sports by overtime group: < 10h = 17%; 10 < 30h = 16%; >=30 h = 8%
- Percent of workers in overtime groups with ETS: <10h = 49%; 10 < 30h = 59%; >= 30 h = 62%
- Working overtime >= 30 h/month increased risk of at least one sick building syndrome symptom (OR 2.6, CI 1.4 - 4.5; adjusted for some covariates)
- OR 2.96 for >= 30 h when adjusting for fixed covariates (age, etc)
- Addition to model of lifestyle and stress-related covariates reduced OR to 2.5
|
| Nakamura et al. 1998 |
248 male non-management white collar workers:
- Age M 31, R 21 - 56
- Japan |
- From time clocks between 1990 and 1993
- Overtime: average monthly work hours beyond 40 h/wk
|
1990 and 1193 measured height, weight, abdominal and hip circumference, skin-fold thickness, serum cholesterol/triglycerides |
- Pearson, Spearman Correlation
- Multiple linear regression with stepwise procedures
- Covariates: age, gender, marital status, education and lifestyle (e.g., eating habits, exercise, smoking, alcohol use) |
- Increased overtime correlated with an increase in BMI (r = .218, p< .01) and waist circumference (r = .218, p<0.01) from 1990 to 1993, but not with 1993 measurements alone.
- While controlling for late dinner, overtime associated with an increase in BMI (B = 0.0103, p < 0.05).
- While controlling for age, overtime associated with an increase in BMI (B=0.0405, p < 0.05) |
| Park et al. 2001b |
238 male engineers from 3 electronics manufacturing plants:
- Age M 32
- South Korea |
One-time questionnaire (M h/wk during previous month):* <60; >60 <70; >70
*R 52 - 89 h/wk |
One-time questionnaire:
- Number of cigarettes oer day
- Number of alcoholic drinks per week |
- Analysis of covariance adjusting for age
- Duncan's multiple comparison procedure |
No significant differences in mean number of daily cigarettes smoked or mean number of weekly alcohol drinks across the three working hour groups |
