The annual number of hours worked per person in the United States surpasses Japan and most of Western Europe.

[International Labour Office 2002]

Overtime is common in the United States and has increased steadily from 1970 through the 1990s [Hetrick 2000; Rones et al. 1997]. According to the International Labour Office [2002], the annual number of hours worked per person in the United States surpasses Japan and most of Western Europe. Figure 1 displays the average annual work hours for the locations of studies discussed in this document [International Labour Office 2003]. As illustrated, work hours in the United States are only surpassed by Thailand, Hong Kong, and South Korea.

This document provides an integrative review of selected health and safety issues associated with overtime and extended work shifts. Findings are summarized as reported by the original authors, and the study methods are described, but not critically evaluated. For this document, overtime is defined as more than 40 hours per week and extended work shifts are defined as shifts longer than 8 hours.

Seventy-five research reports, including one meta-analysis, were identified according to the following criteria:

1. Focused on overtime or extended work shifts
2. Published from 1995 through 2002
3. Peer-reviewed publication
4. Published in the English language

The information retrieval databases used to identify reports include Medline, Current Contents, PsycINFO, and ScienceDirect. Keywords used in the search were overtime, extended work shifts, work hours, work schedule tolerance, 12-hour shifts, 10-hour shifts. Additionally, the references cited in the retrieved reports were examined for any relevant research reports. The studies examined a variety of health and safety issues, ranging from illnesses and injuries to social life and job satisfaction. The present report is limited to a summary of those studies that addressed associations between long working hours and illnesses, injuries, health behaviors, and performance. The health behaviors include physical activity, smoking, alcohol use, and body weight. Performance measures include automobile crashes, tests of cognitive functioning, executive functioning, subjective alertness, cardiovascular fatigue, and muscle fatigue. Of the 75* reports examined, 51 studies and one meta-analysis addressed these outcomes and are summarized below. The summary of findings does not include the remaining 23 reports that did not examine illnesses, injuries, health behaviors, or performance.

Figure 1. Average Annual Work Hours by Country [International Labour Office 2003]

Index: Main Page Table 1 Table 2 Table 3 Table 4 Table 5 Table 6 Table 7 Table 8 Table 9 Abbreviations Acknowledgments Introduction Description of Work Schedules and Samples Health and Safety Findings Summary Concluding Remarks References