Meta-analysis of shift work and occupational injury and illness

Background: Due to advent of the “24 hour society” more individuals must work during non-standard hours. The Bureau of Labor Statistics reported in 2004 that an estimated 15 million people in the United States were employed full time in shift work positions. This poses the threat of many adverse health effects attributable to disturbances of the natural circadian rhythm resulting in reduced performance, increased accident rates, sleeplessness or other health conditions.

Objectives: 1) To assess the correlation between shift work and increased occupational injury and illness 2) To evaluate the association between disruption of the normal circadian rhythm due to shift work and adverse health effects

Methods: Search was done using PubMed and Highwire with the terms shift work, occupational injury and work-related illness from January 2000 to present.

Results: The misalignment of the natural circadian rhythm has been associated with adverse metabolic health effects. Results of epidemiological studies indicate that shift workers have increased levels of triglycerides in comparison to non-shift workers. Higher incidence rate of occupational injury has also been observed during nonstandard work hours, with higher rates of injury reported in the afternoon and night shift in comparison to the morning shift.

Conclusion: Symptoms experienced by shift workers mirror the indicators of jet lag. They complain of gastrointestinal issues, fatigue and sleepiness during work periods. Sleepiness and chronic fatigue due to shift work and extended work hours can contribute to error resulting in increased accidents and injury.