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March 24, 2011
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Force Science Institute Destroying Myths & Discovering Cold Facts
with Force Science Institute

Anti-fatigue measures could cut cop deaths 15 percent, researcher claims

Dr. Bryan Vila, a former 17-year veteran street cop in Los Angeles, says that a mix of poor personal habits and arbitrary agency policies are putting officers at risk

A leading sleep researcher argues that officer deaths from vehicle accidents and violent attacks could be cut by at least 15 percent — “a pretty darned conservative estimate”—if the problem of police fatigue was seriously addressed.

As it is, he claims, a toxic mix of poor personal habits and arbitrary agency policies is creating a “large pool of officers at risk.”

These assertions come from Dr. Bryan Vila, a former 17-year veteran street cop in Los Angeles who now directs the Simulated Hazardous Operational Tasks laboratory in Washington State University’s Sleep & Performance Research Center in Spokane. Author of the landmark book Tired Cops, Vila spoke at the latest IACP annual conference as a panelist discussing “Strategies for Promoting Officer Safety by Managing Fatigue and Work Hours.”

He expanded on his remarks in a recent interview with Force Science News about the impact of long shifts, rotating schedules, and insufficient sleep on police reaction time and threat decision-making.

Sobering Stats
First, some sobering statistics Vila shared with his IACP audience. According to a survey by the AAA Foundation for Traffic Safety, among officers in the US and Canada:

• 53 percent get less than 6.5 hours of sleep daily (compared to 30 percent of the general population)
• 91 percent report feeling fatigued “routinely”
• 14 percent are tired when they start their work shift
• 85 percent drive while “drowsy”
• 39 percent have fallen asleep at the wheel

Vila identified some of the many unwelcome consequences. “Fatigue decreases attentiveness, impairs physical and cognitive functioning, diminishes the ability to deal with challenges, and sets up a vicious cycle: fatigue decreases your ability to deal with stress and stress decreases your ability to deal with fatigue.

“So far as health and wellness are concerned, chronic sleep deprivation is associated with cardiovascular disease, gastrointestinal disorders, sleep apnea and other sleep disorders, and metabolic syndrome—the group of risk factors that increase your chances of coronary artery disease, stroke, and type-two diabetes.”

And, he estimates, fatigue is likely to be responsible for at least 15 percent of officer deaths and career-ending injuries from vehicle crashes and felonious assaults.

Flawed Driving
The greatest risk from drowsy driving seems to come from cops heading home fatigued after shift. Before the obvious hazard of falling asleep at the wheel occurs, there’s the issue of momentary inattentiveness.

“A drowsy driver does not experience a steady decrease in driving ability,” Vila explains. “You get random, but increasingly frequent, lapses of attention. You space out for a few seconds.

“Most of the time, you get away with it. If you’re on a straight, flat road with no other traffic, it can be no harm, no foul. But if the road turns while you’re inattentive, you’ve got a problem.” He cites the case of a California officer driving home up a winding canyon on a bright Sunday morning. “During an attention lapse, the road curved and he kept going straight — out of lane and into a swarm of bicycles coming downhill. He killed two riders, a horrible tragedy.”

During their work shift, periodic shots of adrenalin may help officers stave off drowsiness until they’re off-duty, Vila speculates. “But then when the adrenalin wears off, the payback comes.” More research is needed, he says, to clarify the adrenalin-fatigue interaction and its effect on performance.

Combat Limitations
Fatigue is also “a prime candidate for affecting how well you do in a combat situation,” Vila says. Again, specific research findings are sparse, but “the best information so far strongly suggests that long work hours and erratic, insufficient sleep put officers more at threat in confrontations, as well as driving,” he says.

Among other things, as you get more and more tired, you experience a “cognitive narrowing” that can cause you to miss important elements in your surrounding environment, Vila explains. This is similar to the so-called “tunnel vision” stress reaction that is common in a threat situation and indeed may accentuate that phenomenon, Vila says. “You’re not able to shift focus readily with a lot of competing demands on your attention.”

Moreover, the fatigue-related narrowing can also impede your decision-making. “Your judgment is likely to be compromised,” he says, “and the risk increases that you won’t make as good decisions as you otherwise would. When you’re tired, you tend to latch onto a ‘solution’ for challenges that confront you and stick with it even when objective information suggests it is wrong.

“Parts of the brain that we know are especially vulnerable to fatigue are those that help you control emotion and arousal and those that direct the executive functions, such as making and realizing the consequences of decisions.

“These elements obviously affect your ability to survive life-threatening challenges. Being tired puts you at a substantial disadvantage, compared to being fully alert and having your best faculties for detecting and addressing the threat.”

Self Monitoring
What’s also certain from studies of astronauts, fighter pilots, and other subjects is that “human beings are lousy judges of how impaired they are from fatigue,” Vila says.

“One of the first parts of your brain negatively affected by lack of sleep is the part that looks in on yourself and reports how you’re doing. That means that one of the first pieces of safety equipment to go down as you get more tired is your tiredness monitor.

“Your cognitive ability can be affected by fatigue, without your realizing it, to the same degree as someone who’s drunk. In tests even of elite professionals, people’s reports of how tired they are don’t relate accurately to how tired they really are. In short, you just can’t self-monitor fatigue worth a damn.”

Agency Adaptations
Protecting officers from fatigue disasters requires a collaborative effort between agencies and personnel, Vila advises.

He believes agencies can help by scheduling shifts to more closely mirror natural body rhythms. “We don’t have full information yet on what’s the perfect shift or at least the least harmful shift,” he says. “But the officers most at risk seem to be those who work through the night, because the body’s natural circadian rhythm is to be awake and working in daylight.

“In most people, there tends to be a gradual decrease in alertness after ten or eleven o’clock at night, hitting bottom between three and six in the morning. From about six onward, light rays from the sun trigger cells in your brain that promote a renewed cycle of alertness.

“The longer your shift is in darkness, the more at risk of fatigue you are. If you’ve been up for 12 hours, you’re more at risk at four in the morning than if you’ve been up for 12 hours and it’s four in the afternoon.”

“Departments often just arbitrarily pick the times for shifts to begin and end, but with a little flexibility they could favor the night-shift officers, who are most at risk. Get them started earlier and off the job and in bed earlier, even if it means the day shift has to start earlier.”
Also, he points out, “departments don’t have to have the same length of shifts all around the clock. They could have 12-hour shifts during the day and eight-hour shifts at night. And they could sharply limit the number of night shifts an officer works consecutively. The more night shifts you work in a row, the less and less resilient you become to being tired. After about 3 consecutive night shifts, you’ll start to see a substantial problem and you need time off so you can catch up on your sleep.”

For more than a decade, Vila has advocated that agencies provide a “napping room” where officers can take 20- to 40-minute restorative breaks during duty hours. “Even if you don’t fall sound asleep, just lying down with your eyes closed for 30 minutes in an absolutely dark and safe room can have a major refreshing effect,” he says.

“All this may be a bit of a pain for administrators,” Vila acknowledges, “but it’s smart in terms of risk management. Departments will end up getting better work out of their people while keeping them safer.”

Personal Responsibility
“You need to be your own first line of defense in combating fatigue,” Vila emphasizes.

Among the personal issues that affect whether you get the recommended seven to eight hours of quality sleep per 24 hours are these:

• What’s your sleep environment? “Are you sacking out in the La-Z-Boy with the game on and getting up every hour or so to do things?” he asks.
• How much caffeine are you taking in?
• What’s your overall level of health and fitness?
• Are you working a 12-hour shift and then tacking on overtime or a second job?
• If you work nights, are you scheduling sleep appropriately?

“The farther into the day that you first try to sleep, the fewer consecutive hours of sleep you’re likely to get,” Vila explains. “If you can go to bed at five to seven in the morning, good. But if you wait ‘til noon, sleep is harder to sustain.”
Dealing effectively with the fatigue issue in law enforcement is really “a tightrope walk,” Vila says. “Agencies have to back the demands for service in their community with concern for the needs of the officers they put on the street to meet those demands. But by the same token, if officers are not making rest and resilience priorities for themselves, whatever departments do may not be enough.”

New Research Ahead
During the next two years, Vila and his research team plan to conduct controlled laboratory experiments that he hopes will provide a scientific basis for managing police fatigue. Supported by joint funding from California POST and the federal DoD, they will study the cumulative impact of work-related fatigue on the performance of experienced patrol officers in three critical operational tasks: vehicle driving, deadly force encounters, and reporting.

Vila says: “Even though research involving other professionals makes clear that fatigue from sleep loss degrades human performance while driving, making decisions, collecting information, communicating, and reporting, little is known about the magnitude of those effects in police work. That is important knowledge we need in order to manage police fatigue in a cost-effective manner.”

The study will involve 80 officers, half of whom work night shifts and half who work days. Each officer will take a battery of tests twice, once while highly fatigued, and another time when rested. Their sleep will be tracked using wrist actigraphs and their performance will be measured in the WSU Sleep & Performance Research Center, using MPRI PatrolSimIV driving simulators, AIS PRISim L1000 deadly force judgment and decision-making simulators, and in a computerized field report writing simulation as well as a set of vigilance and fatigue assessments.


About the author

The Force Science Institute was launched in 2004 by Executive Director Bill Lewinski, PhD. - a specialist in police psychology -- to conduct unique lethal-force experiments. The non-profit Force Science Institute, based at Minnesota State University-Mankato, uses sophisticated time-and-motion measurements to document-for the first time-critical hidden truths about the physical and mental dynamics of life-threatening events, particularly officer-involved shootings. Its startling findings profoundly impact on officer training and safety and on the public's naive perceptions.

For more information, visit www.forcescience.org or e-mail info@forcescience.org. If you would benefit from receiving updates on the FSRC's findings as well as a variety of other use-of-force related articles, please visit www.forcesciencenews.com and click on the "Please sign up for our newsletter" link at the front of the site. Subscriptions are free.





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