Graveyard Shift Blurs Officers’ Day

For police officers on the graveyard shift in Philadelphia, each day can be a blur of confusion, fatigue and malaise. The stress builds up over time, producing high rates of alcohol and sleeping pill use, accidents and estrangement in families.

The problem is in the schedule, not the job, said neuroscientist Charles Czeisler of Harvard Medical School. According to Czeisler, the typical schedule, which rotates officers through graveyard, evening and day shifts, fails to accommodate the body’s natural circadian rhythm--the biological clock--which controls individual sleep-wake cycles.

Czeisler redesigned the schedule of a group of Philadelphia police officers and detectives. The new schedule made three major changes.

First, workers changed shifts every 18 days rather than every eight days, allowing more time to adjust to the change.

Second, the rotation shifted forward--from day, to evening, to graveyard--rather than backward as before. Since the typical circadian clock runs on about a 25-hour day, the natural tendency is to shift to a later hour; shifting to an earlier hour makes readjustment more difficult.

Third, Czeisler reduced the number of consecutive days worked from six to four to allow officers to catch up on sleep, thereby avoiding the cumulative sleep deprivation night-shift workers often experience.

After 11 months on the new schedule, officers reported significant declines in sleep problems, sleepiness on the job and fatigue and an increase in alertness.

On-the-job automobile accidents fell by 40%, sleeping pill and alcohol usage dropped 50% and sick time declined 23%.

Family satisfaction with the new schedule increased fivefold. Although the quantity of time spent with families remained about the same, the quality improved. Officers said they felt more rested, more energetic and less irritable.