Shift Work, Sleep Deprivation, and Jail Schedules1

(hypertension, diabetes, increased cholesterol levels) sleep problems have been shown to lead to increased incidence of cardiovascular disease, and shift workers may have as much as 40% increase in risk of CVD (Bøggild, H. Knutsson, A., 1999).

The fatigue and reduced level of alertness that comes along with sleep problems and working during biological night has other mental and behavioral effects. Mental alertness and cognitive process are made less effective, leading to reduced productivity and, in the case of correctional institutions, increased chances of missing critical events or behaviors. Shift work is associated with an increased rate of accidents on the job, and, even more common, accidents driving home from work at the end of a long late shift. In addition, irritability is increased and inhibitions can be reduced during sleep deprivation (Folkard et al, 2005). People working during sleep deprivation are likely to have incidents of “micro-sleep”—unnoticed (even by themselves) periods of very brief sleep or nodding off (Swenson et al., 2008).

Reduced mental alertness, lower levels of working memory capacity and lessened cognitive abilities are reflected in poorer performance with respect to self regulation, self control and risk assessment; poorer judgment, increased impulsiveness, poorer reasoning skills and more “sloppy” behavior on the job (Alhola, & Polo-Kantola, 2007, Kimberg, et al., 1998).

These problems also have additional implications for organizations. Sleep problems from shift work have been related to increased absenteeism and rates of staff turnover and greater use of sick time (Caruso, et al., 2004). Because of these absences, it also often results in increased use of overtime, often resulting also greater use of less experience staff to cover for absences.

40 hours of total work per week, show increased fatigue, reduction in alertness, cognitive functioning, performance on vigilance tasks, and increases in the level of injuries and health complaints (Caruso, e al., 2004). One study of nurses found no differences in performance between 12 and 18 hour shifts with respect to cognitive ability provided the subjects were able to get adequate (7 hours) sleep (Thomas et al., 2006).

The US Navy has traditionally used 6 hour shifts for seamen (6 hours on duty, 6 hours on other assignment, 6 hours sleep), creating effectively an 18 hour work day. Recent research has indicated, however, that these 18 hour days lead to more problems in fatigue and performance than schedules that synchronize with the biological 24 hour day. Because of this research, the navy is considering abandoning their traditional schedule for one based on 8 hour shifts (Crepeau at al 2006).

In industrial settings, longer shifts, whether from regular schedules or overtime, have led to much higher accident and injury rates. Working at least 12 hours per day was associated with a 37% increased risk of injury. Working 60 hours/week or more led to a 23% increase. There appears to be a linear relationship—as hours per day worked increases in regular schedules the rate of injuries rises. There is also a higher risk of accidents during night shifts, and one study found 10 hour shifts had 13% increased injury risk than 8 hour shifts, with 12 hour shifts having a 27% greater risk of injury. (Folkhard et al., 2005). Even though many workers claim that their social and domestic life is better with 12 hour shifts but performance declines compared to 8 hour shifts (Mitchell & Williamson 2000).

Regulation of overtime. Accidents, especially while driving home from a shift, is a serious concern when staff members are drowsy from overnight shifts or significant overtime. Managers need to take care of the amount of overtime and condition of staff leaving the institution. “A key issue with 12-hour shift systems and the potential for increased fatigue and reduced alertness is the regulation of overtime (Gould, 1989 cited in Baulk et al, 2009, p. 697). This should be systematically regulated and tracked in order to avoid further extension of wakefulness wherever possible (or so that additional safeguards can be used if wakefulness is extended beyond acceptable limits). Most regulated systems specify that no longer than 4 hours of additional work be added to any 12-hour shift, and also that a minimum period of 8–10 hours of rest break be taken following any period of extended work.” (Baulk et al., 2008, p. 697)

Others suggest that, where possible, staff should avoid especially risky duties in the hours before normal biological waking (3–5 am) and do things to increase alertness “such as conversations, walking about or exercising, having healthy snacks, or going into brightly lit areas.”(Swenson et al., 2008, p. 305)

Physical conditions. Circadian rhythms respond to levels of light and dark. Providing high intensity lighting (1000 lux or greater) in the workplace can help reduce sleepiness. It may be just as important to assure darkness at home for sleeping with drapes, eye masks, etc. (Burgess et al., 2002).

____________________________________

Richard E. Wener, Professor Emeritus of Environmental Psychology in the Department of Technology, Culture and Society at NYU. In 2010 Professor Wener was a Fulbright Fellow at the Vienna University of Technology. For more than thirty years Professor Wener has studied the way correctional architecture affects facility operations and the behavior of staff and inmates. This work began in 1975 with evaluations of the first of the “new generation jails”—federal Metropolitan Correctional Centers in Chicago and New York. He was a member of the team that studied conditions of confinement to support revisions of American Correctional Association standards for the design of jails and prisons. His writing has addressed design and management features which serve to reduce violence, vandalism, and stress in correctional settings by understanding the lessons of successful direct supervision facilities. Contact Prof. Wener at rwener@nyu.edu.