Workload and health complaints in overtime workers: a survey

In epidemiological studies on workload and complaints on health, the dose-response relationship should be assessed to design a strategy for the prevention of disease or disability. Evaluation for the relationship between workload and complaints were urgently required.

The study population consisted of 109 male workers at a car manufacturer workplace. These observations were analyzed to determine exposure to load and subjective complains by standardized questionnaire. Workloads of the target subjects were divided into four groups (A to D), according to the scores of a self-administered questionnaire.

Percentage of feeling stressful to each of seven items such as overtime work, irregular work, official trip, nighttime work, no rest and/or no nap, mental workload, and physical workload were 62.4, 34.9, 0.9, 23.9, 18.3, 65.1, and 33.9%, respectively. Pearson's moment correlation coefficient between workload and health complaint was 0.585. After adjusting for age, it became 0.586. Furthermore, odds ratio of the subjects who were grouped into C or D were 13.6 (95% confidence interval 3.0 to 61.4) and 48.0 (95% confidence interval 4.3 to 537.3) against group A, which were all significant.

There was a significant relationship between workload and health complaints in this questionnaire survey. To prevent or lower complaints of workers, improvements of working conditions such as overtime work are recommended to reduce health risk.