San Rafael, CA (PRWEB) June 11, 2009
Although most managers are aware that shiftworkers don't sleep as well as other employees, few understand how their organization's shift schedule contributes to the problem. A leading shiftwork consulting firm, Shiftwork Solutions LLC, examined three major shift schedule attributes that affect employee sleep: (1) shift length, (2) fixed vs. rotating shifts, and (3) shift start times. Results of their analysis are summarized below:
Employees working 8-hour day shifts get an average of 6.5 hours of sleep on the days they work. They get 6.8 hours of sleep while working the afternoon shift, 6.1 hours on night shift, and 7.5 hours on their days off. Employees working 12-hour day shifts get an average of 6.3 hours of sleep on the days they work. They get 6.2 hours of sleep while working the night shift and 7.5 hours on their days off.
Jim Dillingham, a partner at Shiftwork Solutions LLC, notes that drawing conclusions from these numbers can be misleading. At first glance, it appears that people working 12-hour shifts get less sleep than those on 8-hour shifts. But this is not the case over a span of several days or weeks, because 12-hour shifts provide twice as many days off and employees sleep longer on their days off. Over a four-week period, workers actually get more sleep on 12s than 8s.
Fixed Shifts vs. Rotating Shifts
Employees working rotating 8-hour shifts average roughly the same amount of sleep over a four-week period as people working a fixed night shift schedule. They get less sleep than people working a fixed day shift or fixed afternoon shift. In addition to improved predictability, fixed shifts allow workers to sleep at approximately the same time each day. This avoids the physical stress (and poor quality sleep) most people experience when they adjust their circadian rhythm to a new sleep period with each shift rotation.
Shift Start Times
Dan Capshaw, also a partner at Shiftwork Solutions LLC, describes his experience at a large auto manufacturing plant with two different shift schedules that were an hour apart. Three-quarters of the workers on day shift started work at 6:30 a.m. The rest started an hour later. When surveyed, employees with the later starting time said they got an average of 34 minutes more sleep on the days they worked than employees with the early start time did. Workers with the earlier start time did not go to sleep earlier, probably because of personal, family or social activities. On their days off, both groups got about the same amount of sleep.
Detailed results of this analysis were published in the March 1, 2008 issue of Occupational Health & Safety. Copies can be found at: OHS Article: Warding Off Sleepiness.
Consultants from Shiftwork Solutions LLC have helped hundreds of companies in a variety of industries to develop shiftwork solutions that satisfy business requirements, employee preferences, and health/safety considerations. The company's two partners, Dan Capshaw and Jim Dillingham, have worked as consultants in this specialized field for more than 17 years apiece.