By Karen Amendola, PhD, Chief Operating Officer, Division of Research, Evaluation, and Professional Service, Police Foundation, Washington, D.C.
The IACP Research Advisory Committee is proud to offer the monthly “Research in Brief” column. This column features evidence-based research summaries that highlight actionable recommendations for Police Chief magazine readers to consider within their own agencies. The goal of the column is to feature research that is innovative, credible, and relevant to a diverse law enforcement audience.
ew findings hold promise for agencies concerned about budgets and officer wellness. Data from a study conducted by the Police Foundation show that 10-hour shifts offer cost savings and other benefits over traditional 8-hour shifts. Officers who work traditional 8-hour shifts worked significantly more overtime—on average five times more—than officers working alternative 10-hour shifts.
In addition to saving overtime expenses, 10-hour shifts also offer other advantages, including more sleep per night and higher job satisfaction. The data come from The Shift Length Experiment: What We Know About 8-, 10-, and 12-Hour Shift Schedules in Policing, a publication stemming from a study funded by the National Institute of Justice. This study was the first comprehensive, randomized experiment of compressed workweeks in law enforcement. For more information, visit http://www.policefoundation.org/content/shift-length-experiment (accessed February 11, 2013).
The study was designed to test the impacts of three shift lengths (8-, 10-, and 12-hour) on performance, health, safety, quality of life, sleep, fatigue, alertness, off-duty employment, and overtime among police.
In addition to the scientifically rigorous research design and methodology, the number of measures the team used to analyze the impact of shift length makes this study one of the most comprehensive ever undertaken. The outcome measure data included departmental data, laboratory simulations and exercises, and previously validated self-report instruments. The experiment was conducted in the Detroit, Michigan; and Arlington, Texas, police departments between January 2007 and June 2009.
Ten-hour shifts have advantages over 8-hour shifts. Ten-hour shifts appear to offer some advantages over 8-hour shifts, both individually and organizationally, with no noted disadvantages. For example, those officers working 10-hour shifts got significantly more sleep per night (more than half an hour more) than those on 8-hour shifts and had a significantly higher quality of work life. Also, those on 10-hour shifts worked the least amount of overtime of the three groups, potentially resulting in cost savings.
The benefits of 10-hour shifts do not extend to 12-hour shifts. Although it may be expected that some advantages associated with 10-hour shifts would inure to those on 12-hour shifts, researchers did not find that in this study. For example, while those on 10-hour shifts got significantly more sleep than those on 8-hour shifts, the same was not true for those on 12-hour shifts. Also, those on 10-hour shifts had a higher reported quality of work life than those on 8-hour shifts, but those on
12-hour shifts did not. While officers on 12-hour shifts worked less overtime than those on 8-hour shifts, they still worked more than those on 10-hour shifts.
Twelve-hour shifts may pose safety risks to officers and the public. While shift length did not impact safety (for example, driving and reaction time), those assigned to 12-hour shifts had significantly lower average levels of alertness at work and were more sleepy than those on 8-hour shifts—something that was not true for those on 10-hour shifts. Because some sleep scientists assert that people underestimate their fatigue levels, the latter two findings should be concerning.
Eight-hour shifts may be more costly than organizations realize. Officers assigned to 8-hour shifts worked significantly more overtime than those on 10- or 12-hour shifts. In our study, officers assigned to 8-hour shifts worked more than five times as much overtime per two-week period (5.75 hours) as those on 10-hour shifts (0.97 hours), and more than three times as much as those on 12-hour shifts (1.89 hours).
Shift length did not have a significant impact on any of our measures of performance, safety, work-family conflict, or health. Performance and safety measures such as interpersonal interactions, shooting skills, risky driving behaviors, reaction time, fatigue, and self-initiated departmental activity were not impacted by shift length.
The groups did not differ with regard to work-family conflict. During the six-month period in which officers were assigned to the experimental conditions, researchers did not detect differences across groups in terms of sick leave taken, stress experienced, increased cardiovascular problems, or gastrointestinal problems.
There do not appear to be any significant health, safety, or performance problems associated with compressed workweek schedules in policing. Indeed, the implementation of 10-hour shifts may be a viable alternative to traditional 8-hour shifts considering the findings of this study. The benefit of additional sleep on the 10-hour shift could potentially improve health, increase safety, and reduce sleep disorders.
It is important to note, however, that the benefits associated with 10-hour shifts did not inure to the 12-hour shifts. Although the study did not reveal any significant effects associated with objective measures of fatigue across shifts, the implementation of 12-hour shifts should be done only after careful consideration of some of the potential concerns.
Limitations of this study include lack of information regarding the methods and costs associated with implementation of compressed schedules, and the low level of reliability for driving and shooting simulation exercises. Future research should examine the impact of overtime hours on fatigue, safety, and performance and on ways to more effectively regulate hours of work in policing. ♦
Please cite as:
Karen Amendola, "Which Shift Is Best?" Research in Brief, The Police Chief 80 (March 2013): 14.