The Shift Length Experiment
The Impact of Shift Length in Policing on Performance, Health, Quality of Life, Sleep, Fatigue, and Extra-Duty Employment
Study Design & Methods:
Using a block-randomized design, this study took the form of a multi-site clinical trial. In two cities, Arlington,Texas and Detroit, Michigan, officers were assigned to either stay on their current shift (which was five 8-hour days) or be assigned to one of two treatment conditions: four consecutive 10-hour shifts or three consecutive 12-hour shifts (followed by a fourth 8-hour shift every other week). This was a pre-post design, so officers were asked to complete self-report measures (paper and pencil tests) of attitudes (quality of work and personal life), behaviors, and stress, as well as sleep diaries and alertness logs for a two-week period during both the pre-test and at the end of the six-month study. In addition, officers completed laboratory-based measures (in the police departments) including: driving performance using a simulator, judgmental shooting using an interactive simulator and laser equipped guns,, interpersonal skills and judgment using video-based scenarios, and fatigue using a pupilometer-type test as well as a reaction time measure.
The results showed that compared to 8-hour shifts, 10-hour shifts resulted in significantly more sleep by officers (approximately 30 minutes more per 24-hour period), significantly reduced overtime, and increased quality of work life. While those on 12-hour shifts also worked significantly less overtime than those on 8-hour shifts, it was still more than those on 10-hour shifts. However, those on 12-hour shifts demonstrated significantly more sleepiness than those on 8-hour shifts. There was also a small to moderate sized effect of alertness, in that those on 12-hour shifts were significantly less alert than those on 8-hour shifts. It is important to note that we controlled for time of day worked (day, evening, or midnight shifts), so these effects were present over and above any effects associated with the time of day worked. We concluded that 10-hour shifts were optimal in that they were associated with the greatest benefits to the agencies and officers, while offering no apparent limitations in terms of sleepiness or lack of alertness as found among the 12-hour group.
Funding & Collaboration:
The “Shift Length Experiment” and associated surveys were funded by the National Institute of Justice (NIJ) of the U.S. Department of Justice (DOJ), with additional support from the Police Foundation.
Implications for Policy & Practice:
The findings from this study suggest that, at least for medium to large police organizations, agencies are likely to see cost savings when implementing 10-hour shifts, and the officers are more likely to have increased safety and wellness associated with increased sleep (about 175 hours more sleep annually) while maximizing alertness on the job. Given previous reported deficiencies in sleep among officers nationwide, implementing four 10-hour shifts consecutively may be one approach to minimizing fatigue-related problems. While other research has indicated that officers got less sleep than in our study, it is important to note that in our study we obtained information on the primary sleep period as well as naps, indicating that officers may indeed manage their fatigue through short naps to supplement their primary sleep period. Finally, officers on 10-hour shifts demonstrated increased levels of quality of work life, which may also be beneficial to their emotional well-being, although there were some differences across sites.
 To ensure all officers were working their required 40 hour/week average over each two week period.
Point of Contact:
Karen L. Amendola, PhD
For more information: http://www.policefoundation.org/content/shift-length
Keywords: compressed schedules; shift length; shift schedules; officer safety, health, and wellness; evidence-based policing; police performance; officer fatigue; overtime
Dr. Karen Amendola Discusses the Shift Length Experiment
NIJ-Harvard webinar, Healthy Officers are Safe Officers: The Nexus Between Performance & Health.
Dr. Karen Amendola's presentation on the shift length experiment at the June 2012 NIJ Conference.
Listen to the January 2013 Office of Community Oriented Policing Services (COPS) podcast on the shift length experiment.
In the Media
The March 2013 issue of Police Chief contains a research-in-brief of the shift length experiment.
The April 2013 issue of COPS Dispatch contains an article by Drs. Karen Amendola and David Weisburd on the shift length experiment.
Publications Documenting the Shift Length Experiment
The Shift Length Experiment: What We Know About 8-, 10-, and 12-Hour Shifts in Policing
Karen L. Amendola, David Weisburd, Edwin E. Hamilton, Greg Jones, & Meghan Slipka (Police Foundation Report; December 2011)
An Experimental Study of Compressed Work Schedules in Policing: Advantages and Disadvantages of Various Shift Lengths
Karen L. Amendola, David Weisburd, Edwin E. Hamilton, Greg Jones, Meghan Slipka
Journal of Experimental Criminology, December 2011, Volume 7, Issue 4, pp. 407-442
Final Report to the NIJ: The Impact of Shift Length in Policing on Performance, Health, Quality of Life, Sleep, Fatigue, and Extra-Duty Employment
Karen L. Amendola, David Weisburd, Edwin E. Hamilton, Greg Jones, & Meghan Slipka (December 2011)
Officer Safety, Health, and Wellness. Karen L. Amendola. In Encyclopedia of Criminology and Criminal Justice (Bruinsma & Weisburd, Eds., 2014). New York: Springer Science+Business Media, 3322 – 3332. Available at: http://link.springer.com/referenceworkentry/10.1007%2F978-1-4614-5690-2_651
Schedule Matters: The Movement to Compressed Work Weeks, Karen L. Amendola & David Wesiburd, Police Chief Magazine, 79 (May 2012): 30–35
Results of a Random National Survey of Police Agencies
As part of the shift length experiment, the Police Foundation conducted a random telephone survey of 300 police agencies to determine the proportion of agencies that have adopted compressed schedules. We also examined variables based on agency size and the use of shift rotation, as well as trends associated with each over time. The purposes of this telephone survey, conducted first in November 2005 and again in November 2009, were to determine the proportion of agencies that use compressed shift schedules (e.g., 8-, 10-, or 12- hour shifts, or some variation) for their field patrol officers, and to identify the extent to which agencies employ rotating shifts. The first report below is a comparison report of the survey results in Time One and Time Two.
Trends in Shift Length: Results of a Random National Survey of Police Agencies
Karen L. Amendola, Meghan G. Slipka, Edwin E. Hamilton, with Michael Soelberg and Kristen Koval (December 2011)
Law Enforcement Shift Schedules: Results of a 2009 Random National Survey of Police Agencies
Karen L. Amendola, Meghan G. Slipka, Edwin E. Hamilton, Michael Soelberg (November 2011)
Law Enforcement Shift Schedules: Results of a 2005 Random National Survey of Police Agencies
Karen L. Amendola. Edwin E. Hamilton, Laura A. Wyckoff (May 2006; revised November 2011)