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Impairment Testing and Field Impairment Test with Predictive Safety

What is Cognitive  Impairment?

Last Updated: 1st February 2018
Workplace Safety
Alertness Test and Impairment Testing with Predictive Safety

Defining Impairment

Generally, impairment means a weakening or hindrance of functionality. When referring to people, impairment describes a cognitive hindrance characterized by an inability to pay attention, think and speak clearly, make decisions, and so on. Impairment can also be physical, which can include balance and mobility problems.


A definition of impairment must also include that in order for functionality to be weakened or hindered, there must be a standard, a norm, of functionality. Impairment is a reduction from one’s individual optimal functionality and therefore is usually a temporary state.

Manage Impairment Testing in the Workplace with Alertness Test

Why Manage Impairment in the Workplace?

Workplace safety is enforced and assured in many ways: regulatory compliance, training, practice, supervision, personal accountability and awareness, risk management, equipment maintenance, signage, safety gear (PPE), and so on.

But the value in each of these measures is reliant on, and limited by, the judgment and behavior of people. For example, proper fall protection equipment will protect from a fall only if used, and choosing to use the equipment is a matter of behavior and judgment. So too is enforcing and ensuring that others use the equipment as required.

But matters of behavior and judgment are not always matters of choice. Behavior and judgment are susceptible to impairment, which can result from unfortunate circumstances, like illness, as much as personal choices, like alcohol intoxication. What does this mean for the work environment? In the same way that machinery needs monitoring and maintenance to keep optimal functionality and prevent interruptions in productivity, people also need attention and care to ensure they are operating optimally.

But machinery and people are quite different. Machinery has no thoughts, no will, no ability to convince itself that it does not need rest or repair. Machinery does not use judgment to determine when it is safe to use. Machinery does not believe it cannot miss a day’s work despite performing poorly or unsafely, and machinery does not think it will be punished as much for a safety-related mistake as it would be for stopping work because of a safety concern. People, on the other hand, can and often do these things.

In fact, our society tends to consider working through fatigue as an inevitability of modern life, and we may even celebrate it as a sign of resilience and strong work ethic, even where safety risks are present. This characteristic of our culture endures in spite of well-established research showing how commonly that cognitive impairment is a factor in workplace accidents and lost productivity.

Impaired workers, such as those who are suffering from fatigue, pose safety risks not only because of the reduction in their physical functionality but also because of the reduction in their cognition, which includes judgment and self-awareness.

For example, the impaired worker may be more likely to forgo the fall protection equipment and downplay the regulation requiring its use.

An impaired worker may not actually recognize her own impairment; she may believe she is functioning at a high level, but in fact is just not cognizant of the deficiency in her performance. And because the nature of impairment and the dangers of fatigue are not as widely understood as they should be in workplaces, a dangerously fatigued worker may be too embarrassed to tell a supervisor that he feels unable to safely operate heavy equipment. Or he may convince himself that he is not impaired and that he can “pull it together.” For these reasons, it is often only until after an incident has occurred that any impairment is discovered.

With impairment testing, we can mitigate the likelihood of an accident
to occur due to cognitive impairment, which we will
go more in depth in the next coming sections.

Causes of Cognitive Impairment

Causes of Cognitive Impairment

Because the brain controls both the mind and the body, cognitive impairment and physical impairment can often exist together. For example, acute drowsiness, a symptom of fatigue, can lead to heavy eyes and nodding off, and alcohol intoxication is known to affect motor skills and balance. Though not all forms or degrees of cognitive impairment have visible characteristics, behavior will likely be affected through involuntary actions like yawning and other forms of diminished physical self-control.

Cognitive impairment can have a number of causes, and not all of them are visibly apparent. And because impairment affects judgment too, an impaired person may not recognize or agree that his or her performance is diminished. Because many conditions and circumstances can lead to impairment, employees and employers alike can mitigate its impact on workplace safety and productivity by learning more about it and its many causes.

Impairment Testing and Marijuana Impairment Testing


FatigueWorker fatigue is one of the most common contributing factors to workplace accidents and near-misses. Fatigue can manifest from of a number of reasons, both work-related and not. Most fatigue and its symptoms accompany sleep debt, an accumulation of insufficient restorative sleep, but it can also arise from mental or physical exertion, personal health factors, and psychosocial factors. Regardless of its cause, fatigue is more than just being tired; it can impair mentally as well as physically.

Shift workers, especially those who work rotating shifts, are especially susceptible to fatigue due to the disruption of their circadian rhythm, or sleep/wake cycle. The human biological system operates on an internal clock in which different functions run on different cycle lengths. The circadian rhythm lasts approximately 24 hours, with various functions rising or falling at various times throughout. These rising and falling functions—heart rate, body temperature, and others—create a powerful physiological tendency to sleep at night and be awake during the day. Difficulties occur when work-time arrangements cause individuals to work against this tendency, which affects both the ability to remain alert and the ability to sleep.

Employees who work rotating shift schedules, in which they alternate between day and night shifts, are especially susceptible to sleep debt and associated fatigue symptoms because it takes time for a person to become better adjusted to a new schedule. In fact, at the beginning of every new shift cycle, workers are much more likely to experience what is commonly called “jet lag,” because they are working against two things: their natural circadian rhythms, which expect them to be awake during the day and asleep at night, and having become adjusted to their previous shift cycle and now must readjust.

Other forms of fatigue are not directly related to insufficient sleep but can arise from stress and would still be alleviated through rest. A workload too difficult or big to handle can lead to stress and fatigue, and so too can personal life crises and the stress they bring. Personal problems may also lead to cognitive impairment from distraction or preoccupation, which is discussed below.


Workplace Safety Solutions with Impairment Testing at Predictive Safety

IllnessBeing sick or coming down with an illness can compromise one’s alertness, as the body is working to fight the bug. The mind can be cloudy, and it can be hard to focus when dealing with a cold, the flu, a stomach bug, or other issues.

In the same way that people often feel obligated to work despite being fatigued, many often feel similarly when fighting illness, believing that working while sick is necessary, virtuous, or both. In reality, compromised alertness can cause serious performance detriments that may go unnoticed by the impaired employee.

In addition, presenteeism can cause illness to spread, creating a domino effect of sickness and lost productivity among an entire workforce.

Some employees may use over-the-counter or even prescription medications to combat their symptoms and be more effective at work. But although the medications may help how the employees feel, they may have side-effects that don’t make up for the loss in alertness that the illness caused, instead causing a mild intoxicating effect. Even medications that claim to be “non-drowsy” formulas may still bear warnings about operating machinery or driving a car while using them.

Field Impairment Test and Alertness Test


DrugsPre-employment and random drug testing has been a regular fixture in workplaces since the 1980s,

and some might think of drug use as the most common or most concerning cause of impairment among employees. Although it is relatively uncommon, especially when compared to other causes of impairment in the workplace, drug use is known to have been a contributing factor in incidents and deserves attention in workplace safety.

Although illicit and prescription drugs tend to impair in one way or another, they come in myriad types, forms, and usages, and the degree to which they impair differs from drug to drug and from person to person. Many workplace drug tests do not account for all possible intoxicating and impairing substances, including prescription and over-the-counter medicines, nor can they keep up with all new “designer” and “club” drugs that occasionally surface in our society. As a result, identifying intoxication and impairment from drugs can be tricky. It may even be true that someone could test as intoxicated but exhibit no impairment, and vice versa, as can be the case with marijuana.

Drugs also present another quandary: withdrawal. A person can have symptoms of withdrawal after stopping use of a drug to which he or she had become dependent. These symptoms can be mild or severe, and they can affect alertness and cognition. The dangers of withdrawal symptoms can exist whether the ceased substance was an illegal drug, prescription medication, or alcohol.



DrinkingAlcohol intoxication is a bit more common than drug use as a factor in workplace incidents. Plus it is easier to identify through personal observation and body fluid testing. Impairment from alcohol intoxication is characterized by compromised balance and speech, diminished mobility and dexterity, and lessened focus, judgment, and decision-making. In fact, the symptoms of moderate alcohol intoxication and advanced fatigue are comparable if not indistinguishable from each other.

But the safety risk that alcohol intoxication can present a workplace is probably more often unrelated to drinking alcohol while on the clock or during a lunch break, as the issues that heavy drinking can cause can linger into the next day in the form of a hangover. The symptoms of a hangover might not be visible to supervisors or co-workers, but they can be severe, leading to painful headaches and sensitivity to noise and light, nausea and vomiting, and not to mention cognitive impairment, foggy-headedness, reduced reaction time, diminished mobility, and so on.

Impairment Testing and Workplace Safety Test

Emotional Distress and Preoccupation

Emotional DistressEveryone can be affected by life’s ups and downs, and these can cause us to focus on those things, whether they’re bad or good, or even in between, as many things in life can at least cause our minds to wander. Our brains are very good at turning on “auto pilot,” especially when doing repetitive or monotonous tasks, and a preoccupied mind may be unable to react as quickly to sudden problems as a focused mind.

Emotional distress caused by bad news or personal crises, like relationship or marital problems, the loss of a loved one, financial woes, or even animosity among co-workers may contribute to diminished attention to the work environment, potentially leading to diminished productivity and lapses in safety.

Impairment Testing and Safety Culture at Work

Where Impairment, or Non-Alertness,
Fits into Safety Management

Being “fit for duty” means an individual is physically, mentally, and emotionally capable of performing his or her work without posing a danger. Yet many workplaces rely on measuring “lagging indicators”—things like the number of days since the last recordable incident, the results of safety audits and employee drug tests—to assume their present safety performance, and “fitness for duty” is often conflated with clean urine tests rather than the capability to perform work.

As a result, the word “impairment” has become associated with intoxication, and all the other causes of impairment tend to be overlooked. But the oversight may have persisted also due to a lack of methods to approach the wider problem, especially since the notion of “fitness for duty” gained understanding in the safety and human resources arenas. However, the advent of the Internet, cellular communications, mobile smart devices, and data analytics present new ways of tackling the issue of impairment in the workplace, and in a way that changes how we think about impairment.

A different approach to impairment within established workplaces represents a shift in culture, but cultural shifts are difficult to force. An issue with the term “impairment” is that it implies the presence of something rather than a reduction of something, and therefore it remains easy to synonymize it with intoxication, the presence of intoxicants. Using different terms that do not carry the stigma of impairment might help bring about the cultural shift more easily, for example, reduced alertness or non-alertness. The word alertness better implies a norm or standard, and people may more readily understand that one’s alertness can vary for many reasons rather than realize that impairment is also a matter of degrees and many causes, when only the language used is different.

Addressing fatigue and non-alertness creates a cultural shift where supervisors and managers better understand the human element of their workforce. This can lead to more intelligent shift and break scheduling by optimizing crews or job tasks according to time of day, even potentially reducing the need for overtime because shift performance is improved. Plus, employees become more attentive to their own states of mind and fatigue levels. When non-alertness is considered (instead of problematic impairment), it can improve mindfulness and self-accountability among the workforce, and it can reduce the number of occasions in which poor performance or unsafe behavior would lead to a punitive response if not also cause a safety incident.

The shift in culture that managing alertness and fatigue can inspire is both cause and consequence of an absence of regulatory guidance in many industries. Where scant regulations do exist, they focus on limiting the number of hours worked over particular numbers of days. Although such limitations are important to help reduce the impact of work-related fatigue, they do not—and cannot—address all possible sources of fatigue or impairment generally. Because impairment can result from innocuous and common circumstances, regulatory agencies cannot regulate affect life outside the workplace nor things unrelated to the occupational arena.

As a result, it remains the responsibility of businesses and organizations to proactively manage employee alertness if not also monitor their fatigue. Even in companies where non-alertness or fatigue risk may be thought to have minimal safety impact, alertness monitoring and fatigue management can benefit performance and improve productivity because managers know when employees are operating at their best and can manage them appropriately in the case they’re having an off day.

To combat the safety and performance risks of impairment or non-alertness, Predictive Safety offers two complementary platforms that can suit your organization’s structure and needs in a cost-effective way:
AlertMeter Alertness Test and Cognitive Impairment
AlertMeter® is a simple graphic cognitive impairment test that takes 60 to 90 seconds to complete at the start of a shift, before undertaking complex or safety-sensitive tasks, when returning from lunch, or other times as appropriate for your work environment. It is sensitive to any deviation in an employee’s normal alertness levels, whether because of fatigue, alcohol, illness, or other causes, which allows a designated supervisor to assess the employee’s fitness for work before he or she can pose a risk.
PRISM Predictive Fatigue Risk Management
The PRISM fatigue management system analyzes many data streams in real-time to assess and predict individual employees’ fatigue risk throughout their shifts and beyond. PRISM allows supervisors to monitor when employees may need breaks and countermeasures—like snacks or drinks, rest, exercise, and so on—to keep up their alertness and performance. PRISM is ideal for occupations and industries with extended shifts, 24-hour shift schedules, and rotating shift cycles. PRISM also incorporates AlertMeter® and can be integrated into virtually any work environment.

References and Further Reading

  • Popkin, S.M., Howarth, H.D., & Tepas, D.I. (2006). Ergonomics of work systems. Handbook of Human Factors and Ergonomics (3rd ed.). Ed. Gavriel Salvendy. Hoboken: John Wiley & Sons.
  • Schutte, P.C. (2009). Fatigue risk management: Charting a path to a safer workplace. The Southern African Institute of Mining and Metallurgy, Hard Rock Safe Safety Conference: Sun City, South Africa.
  • Harrington, J.M. (2001). Health effects of shift work and extended hours of work. Occupational and Environmental Medicine 58(1): 68–72.
  • Van Dongen, H.P.A. & Dinges, D.F. (2005). Sleep, circadian rhythms, and psychomotor vigilance. Clinics in Sports Medicine 24(2): 237–249.
  • Caldwell, J.A., Caldwell, J.L., & Schmidt, R.M. (2008). Alertness management strategies for operational contexts. Sleep Management Reviews 12(4): 257–273.
  • Lerman, S.E., et al. (2012). Fatigue risk management in the workplace. Journal of Occupational and Environmental Medicine 54(2): 231¬–258.
Impairment Testing and Cognitive Impairment with Alertness Test


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