Extended-hours operations, with employees on the job outside of 7 a.m. to 7 p.m., have significantly higher rates of absenteeism and turnover, according to the sixth annual Shiftwork Practices survey by Circadian Technologies.

Managers at 10 percent of the facilities participating in the survey reported that their employees are severely fatigued, up from 6 percent in 2002. The survey found that workers' compensation claims are 15 times higher at operations with severe fatigue problems than at those reporting no fatigue problems. It also found that facilities banning employee napping, an effective measure against fatigue, have workers' compensation costs four times higher than those that do not prohibit napping.

In 2003, absenteeism rates averaged 5.8 percent among extended-hours workers, three times higher than the average rate of 1.9 percent for the entire United States workforce over the same period. Transportation, processing, and health-care industries have the highest absenteeism rates at 7.2 percent, 6.9 percent, and 6.8 percent, respectively. After factoring in the costs of finding replacements, management time, and overtime pay, employer costs for extended-hours employee absenteeism average $3,490 per worker per year, compared with an annual average of $925 for daytime employees.