In a recent article, "Losing Sleep: the Causes and Effects of Sleep Deprivation", TheDoctor sleep experts Namni Goel, Ph.D., and David F. Dinges, Ph.D. discussed the complex nature of human sleep cycles and their implications for those who work irregular or late hours.

Now, a separate meta-study suggests that simple work schedule adjustments might help shift workers in both their work and personal lives.

Shift work is generally defined as including anyone who works nights or any period outside the traditional 7 a.m. to 6 p.m. workday.

It is not only working at night that is disruptive; many shift workers have frequently changing schedules. Instead of a permanent night shift, for instance, some work at night for several days and then rotate to afternoons for several days.

It is well established that shift workers are more vulnerable to substance abuse, sleep disturbances, absenteeism, injuries and accidents.

It is not only working at night that is disruptive; many shift workers have frequently changing schedules. Instead of a permanent night shift, for instance, some work at night for several days and then rotate to afternoons for several days. According to the study, forward-rotating shifts — that is, with each succeeding shift beginning later in the day — seem to be easier on the mind and body, according to lead author, Clare Bambra of the Department of Geography at Durham University in England.

The findings, which appear in the May issue of the American Journal of Preventive Medicine, pulled data from 26 studies of shift workers around the world, including traffic controllers, autoworkers, police officers, nurses and chemical plant employees. According to the study, forward-rotating shifts — that is, with each succeeding shift beginning later in the day — seem to be easier on the mind and body, according to the lead author, Clare Bambra of the Department of Geography at Durham University in England.

As many countries move toward 24-hour societies, shift work is becoming more common in the professional and service sectors. Still, shift work remains more common in lower-paying industries.

"Shift work tends to affect people of lower socioeconomic groups more often, so it could be a factor in the health disparities that we see between groups," Bambra said.

Alec Davidson, Ph.D., assistant professor of anatomy and neurobiology at Morehouse School of Medicine, who studies circadian rhythms in animals, said the study of health promotion among shift workers is in its early stages, but that there is "a huge amount of resistance."

"You'd think there would be motivation to fix these things. Substance abuse, sickness and health — as well as the happiness of the workforce — are bottom-line issues for companies if they could overcome these problems," said Davidson.

The study appears in the May, 2008 American Journal of Preventive Medicine.