From the summary:
This report presents the results of the first known comprehensive randomized experiment of CWWs in law enforcement. The Police Foundation experiment 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 scientifically rigorous research design and methodology, the number of reliable outcome measures employed to analyze the impact of shift length, including departmental data, laboratory simulations and exercises, and previously validated self-report instruments, make this study one of the most comprehensive ever undertaken in this area. The experiment was conducted in the Detroit (MI) and Arlington (TX) Police Departments between January 2007 and June 2009.
The study found some distinct advantages of 10-hour shifts and identified some disadvantages associated with 12-hour shifts that are concerning. It is important that agencies implement strategies and policies that are evidence based, and the findings of this study provide important information for law enforcement leaders and other policy makers to consider when examining both the most efficient and effective practices for their agency, as well as the safety and quality of life of their personnel and the public they serve.
– Trends in Shift Length: Results of a Random National Survey of Police Agencies
Source: Karen L. Amendola, Meghan G. Slipka, Edwin E. Hamilton, Police Foundation, December 2011
– Law Enforcement Shift Schedules: Results of a 2005 Random National Survey of Police Agencies
Source: Karen L. Amendola. Edwin E. Hamilton, Laura A. Wyckoff, Police Foundation, May 2006; revised November 2011
– Law Enforcement Shift Schedules: Results of a 2009 Random National Survey of Police Agencies
Source: Karen L. Amendola, Meghan G. Slipka, Edwin E. Hamilton, Michael Soelberg, Police Foundation, November 2011
– 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, Police Foundation, December 2011, Executive summary