Objective and subjective working hours and their roles on workers’ health among Japanese employees

Abstract

This study investigated the correlation between objective and subjective working hours (OWH and SWH, respectively) and their relation to the workers' health. The study included 6,806 workers of a Japanese company (response rate = 86.6%). OWH were collected as the monthly data during fiscal year 2017 from the company record. SWH were self-reported as the weekly data during the past month in November 2017. Both OWH and SWH corresponded to the same period of one month (October 2017). Additionally, the data for the annual health checkup in fiscal year 2017 and self-reported mental health in November 2017 were collected. The results indicated that the longer OWH was related to more underestimation of SWH. The analyses of covariance adjusted for the selected variables showed that irrespective of OWH or SWH, significant relationships were found for stress responses but not for body mass index, aspartate and alanine aminotransferase, fasting blood glucose, hemoglobin A1c, high-density lipoprotein cholesterol, or triglyceride. However, significant relationships with only OWH were noted for systolic and diastolic blood pressure, low-density lipoprotein cholesterol, gamma-glutamyl transpeptidase, and positive work-related state of mind. The present findings show that SWH should be used carefully when assessing the health effects of long working hours.

Metabolic and Obesity Phenotype Trajectories in Taiwanese Medical Personnel

“…Recall bias might also cause a discrepancy between subjective working hours and objective working hours. This stands in line with a previous study which highlighted that subjective working hours should be interpreted carefully when assessing the health effects of long working hours [43]. In addition, as working hours were examined as a categorical variable, potential curvilinear effects on metabolic and obesity status might also have been neglected.…”

Association between long working hours and liver enzymes: evidence from the Korea National Health and Nutrition Examination Survey, 2007–2017

“…The number of literatures on the relationship between working hours and liver function is limited. In a cross-sectional study of 6,086 Japanese workers conducted by Ochiai et al, 20 no correlation was observed between weekly working hours and abnormal LFT. However, since this study was conducted only in Japanese tertiary industry workers, there are limitations to the generalization of the results.…”

“…A recent study suggested a correlation between weekly working hours and liver damage, but it is difficult to generalize because this study only targeted a specific patient group. 19 20 Therefore, this study aimed to examine the relationship between weekly working hours and abnormal LFT using the data from the Korea National Health and Nutrition Examination Survey (KNHANES), which is a representative sample survey conducted in the Korean population. Considering that the liver is an organ that represents sexual dimorphism 21 and the health effects of long working hours may differ by sex, all analyses were conducted separately by sex.…”

Study profile: protocol outline and study perspectives of the cohort by the National Institute of Occupational Safety and Health, Japan (JNIOSH cohort)

“…The precision between self-reported working hours and company-recorded working hours has not been sufficiently examined thus far 18) . A preliminary assessment in a sub-population of the study cohort showed that the difference between actual working hours and self-reported working hours tended to be greater for those who worked longer hours 19) . The identification of individual and workplace factors that strongly influence the under-and overestimation of working hours will provide important evidence to guide appropriate management of working hours.…”