Managing Work Schedules: An Alertness

and Safety Perspective

Mark R. Rosekind

57

ABSTRACT

Around-the-clock activities ranging from essentials such as

health care and public safety to conveniences like shopping

are pervasive in modern society. These activities create significant physiologic challenges for workers in providing safe and

productive operations. Humans are biologically designed to

be awake during the day and to sleep at night. Work schedules

that oppose this natural biologic rhythm generate physiologic

disruptions that lead to significantly degraded performance

and increased risks to health and safety. Such effects of continuous work schedules on individuals, organizations, and the

public are frequently underestimated, contributing to incidents, accidents, and societal disasters. Still, some scientific

and real-world considerations illustrate the intricacies of managing work schedules, including individual differences, organizational culture, and economic factors. Effectively

addressing these risks is a complex and often contentious

issue that requires a comprehensive and programmatic

approach.

In many studies, workers in around-the-clock occupations

report obtaining less than adequate amounts of sleep and

experiencing sleepiness on the job. Approaches to address

this issue must occur at all levels, from individuals to corporations to society. Individuals can obtain information on the

topics of sleep, circadian rhythms, and alertness strategies,

and organizations and society can facilitate such education.

Organizations can also encourage the use of certain alertness

strategies (such as naps) with support facilities and by

institution of policy, and they can use scientifically based

scheduling practices to minimize risks related to work

schedules.

Individuals, organizations, and society all have important

roles to play in the diagnosis and treatment of sleep disorders,

many of which go unidentified. Effectively managing modern

work schedules, and their associated sleep and circadian

factors, offers an opportunity for sleep medicine to improve

the health and safety of millions of individuals, corporations,

and society.

Modern society has evolved into a world filled with aroundthe-clock activities that range from essentials such as health

care, public safety, and power to conveniences such as shopping.

These activities create significant physiologic challenges for

the humans who must provide safe and productive operations. Human beings have evolved to be active during the

day and to sleep at night. Therefore, any work schedule that

opposes this natural biological programming will create

physiologic disruptions that can lead to significantly degraded

alertness, performance, and safety. These risks affect individuals,

organizations, and the public and are frequently underestimated, leading to the potential for incidents, accidents,

and societal disasters. Effectively addressing these risks is a

complex and often contentious task that requires a comprehensive and programmatic approach.

First, a context will be provided to demonstrate why

managing work schedules is both a health and safety issue

and to show the extremely large number of people affected by

these concerns. Next, effective approaches to address this

issue will be outlined from both individual and organizational

perspectives. Finally, the complexity of managing work schedules will be illustrated by identifying some scientific and realworld considerations that remain challenges to improving

health and safety in around-the-clock settings.

WORK SCHEDULES AFFECT SLEEP,

ALERTNESS, AND SAFETY

In work settings, it’s all about safety. Obviously, the focus of a

text on sleep medicine is health as it relates to the prevalence,

risks, diagnosis, treatment, and other aspects of sleep disorders. Even “basic” research is presented in the context of

clinical sleep medicine and its relevance to sleep disorders.

However, although health and its promotion have become

broadly acknowledged and integrated into work settings, the

primary reason that occupational environments focus on work

schedules is related to safety. This is the paramount concern

in any work environment, and especially in safety-sensitive

settings such as transportation, health care, and public safety.

Even in life-threatening situations, where “getting the job

done” is critical, the safety of everyone, especially the individual operator or provider, is a primary concern.1 This book

superbly addresses the health consequences of sleep loss,

sleep disorders, and shift work. Therefore, the emphasis here

will be on how work schedules affect sleep, alertness, and

ultimately safety.

Any work not done in daytime, in standard working hours,

or on a regular schedule has the potential to significantly

affect both sleep and circadian rhythms. The operational

issues are complex and are related to a variety of factors, such

as the creation of acute sleep loss prior to a work period, the

accumulation of a sleep debt across consecutive days,

extended work periods or on-call schedules, and other issues

to be outlined later. Some examples from transportation,

health care, and public safety demonstrate how work schedules

can create acute and cumulative sleep loss.

A variety of National Aeronautics and Space Administration

(NASA) studies have examined the sleep and circadian disruption of commercial airline pilots.2 For example, in one study,

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Managing Work Schedules 681

long-haul international pilots averaged 7.3 hours of sleep

during a home baseline period prior to a trip. However, while

on their trip, these pilots averaged 5.3 hours of sleep during a

primary sleep period that was supplemented by naps for a total

of 6.5 hours of sleep per 24 hours.3 Short-haul domestic pilots

who had a 12.5 hour layover or off-duty period averaged

6.7 hours of sleep.4 Overnight cargo pilots averaged 4.6 hours

of sleep in their primary sleep period, which was supplemented to a total of 6.3 hours of total sleep per 24 hours. This

was in comparison to the 7.5 hours of home baseline sleep that

they obtained.5 Overall, 85% of the pilots studied in different

flight environments accumulated a sleep debt across their trip

schedules. Their sleep debt ranged from 8 hours on short-haul

schedules to 16 hours on long-haul flight schedules.6

The sleep-wake schedules of truck drivers in different

operations also have been studied.7 In one large study of

commercial drivers operating on different schedules, the drivers

averaged 3.8 to 5.4 hours of total sleep. For example, after

10 hours of day driving, the drivers averaged 5.4 hours of sleep

during their 10.7 hours off-duty. After a 13-hour night drive,

the drivers averaged 3.8 hours of sleep during the 8.6 hour

off-duty period; after a 13-hour day drive, the drivers averaged

5.1 hours of sleep during their 8.9 hour off-duty period.

In a study of train engineers conducted by the Federal

Railroad Administration, the crews averaged 6.1 hours of

sleep with an off-duty period of 12 hours and only 4.6 hours

of sleep with a 9.3-hour off-duty period.8

The sleep-wake schedules of health care providers have

been studied with an increased interest in how this affects

patient safety.1,9,10 For example, emergency department

attending physicians averaged 5.5 hours of sleep after a night

shift compared to 8.3 hours of sleep after a day shift.11 A study

of surgical residents found that they averaged 5 to 6 hours of

sleep while they were on call, whether the schedule was

every other night, every third night, or every fourth night.12

Eighty-nine percent of OB/GYN residents reported less than

4 hours of sleep while on call, and a group of anesthesiologists

reported an average of 4.8 hours of sleep while on call.13,14 In

a recent study, hospital staff nurses reported getting 6.5 hours

of sleep on workdays compared to 7.8 hours on days off.15

Police officers have been found to average 6.2 hours of

sleep while working an 8-hour shift and 6.5 hours when on a

12-hour shift. In one survey, 53% of officers reported an

average of 6.5 hours of sleep or less.16,17 Firefighters averaged

5.1 hours of sleep when working on a night shift schedule

compared to 7.1 hours when working on a day shift schedule.18

These examples from transportation, health care, and public

safety demonstrate the acute sleep loss and cumulative sleep

debt experienced in these work settings. In fact, the amount

of sleep typically averaged on work days is significantly less

than the adult average requirement of about 8 hours. This

becomes a relevant safety issue because acute and cumulative

sleep loss lead to decreased alertness and performance.19-21

Laboratory research has clearly established this relationship.

One integrated demonstration of these findings showed that 5

hours of sleep across 7 consecutive nights created significantly

increased physiologic sleepiness, and these decrements were

highly correlated with decreased psychomotor performance.22

Recently, varying amounts of acute sleep loss (2, 4, 6, and 8

hours) were found to increase sleepiness more than ethanol

and had effects comparable to those of ethanol on degrading

psychomotor performance.23 In this study, 2 hours of sleep

loss equated to a breath ethanol concentration (BrEC) of

.045%, which is the equivalent of ingesting 2 or 3 12-ounce

beers. Four hours of sleep loss equated to a .095% BrEC, the

equivalent of ingesting 5 or 6 12-ounce beers.

The acute and cumulative sleep loss found in various work

settings has been associated with sleepiness on the job. In

NASA studies, 80% of regional pilots and 71% of corporate

and business aviation pilots reported “nodding off” in the

cockpit during a flight.24,25 In another NASA study of longhaul pilots, 154 occurrences of physiologic microevents (i.e.,

alpha or theta electroencephalogram [EEG] or slow eye movements) were recorded during the last 90 minutes of a 9-hour

flight.26 A study of air traffic controllers conducted by the

Federal Aviation Administration (FAA) found that 48% report

“they often fell asleep unintentionally.”27

Police officers also report falling asleep on duty. For example, 80% report dozing off at a stop light once a week,28 26%

nod off during daytime activities, and 41% fall asleep during

a night shift.29 An Alertness Solutions survey found that 85%

of officers reported “unintentionally” nodding off while on

duty (unpublished findings).

In a multiple sleep latency test (MSLT) study of anesthesia

residents, the residents were found to have an average postcall

sleep latency of 5.5 minutes.30 However, their average baseline

(no-call condition) sleep latency was 6.5 minutes, and difference between postcall and no-call MSLT, was not statistically

significant. This demonstrated that both the acute (post-call)

and cumulative (chronic) effects of sleep loss (baseline, no-call

condition) created significant physiologic sleepiness in these

residents. With increased total sleep, the residents’ average sleep

latency increased to a normal range (12.8 minutes).

Overall, 60% to 70% of shift workers report difficulty

with sleep, sleepiness on the job, or actually falling asleep

unintentionally while at work.31

This sleep loss and decreased alertness degrades safety,

the real-world outcome of most significance. Incidents and

accidents due to sleep loss, fatigue, and circadian disruption

have been identified in every mode of transportation and most

around-the-clock operational environments. An extensive

literature describing these fatigue-related, sleep-loss, and

circadian-based incidents and accidents is available, including

in this text.9,32-38 These include major societal disasters such

as the grounding of the Exxon Valdez, the Three Mile Island

nuclear accident, the space shuttle Challenger accident, and

more.36,39-41 Other data also demonstrate the associated safety

risks. For example, in one study 41% of medical trainees

reported having made a fatigue-related error.14 In Alertness

Solutions surveys of health care providers, 19% reported

worsening a patient’s condition and 30% reported injuring

themselves because of fatigue. In a survey of police officers,

Alertness Solutions found that 44% reported acting in an

unsafe manner or taking unnecessary risks because of fatigue

(unpublished findings). Extended work hours have been

associated with a threefold increase in on-the-job accident and

injury rates, and workers with sleepiness complaints had a

more than twofold increased risk for an occupational

injury.42,43

WHO IS AFFECTED?

Data regarding the number of people who are affected by these

issues typically are discussed in the context of “shift work.”

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682 Disorders of Chronobiology

Traditionally, this has focused on the number of individuals

working variable hours, nonfixed day shift, or alternate shifts.

For example, one study of 1997 data published in 2000 indicated that 28% of the U.S. workforce, about 25 million people, worked variable hours.44 In a September 2002 study,

22.2% of men and 21.4% of women worked schedules other

than fixed day shifts.45 In this analysis, to count as occurring

in one of the four shift categories, at least half the hours

worked had to fall into the criteria times for the reference

week. Therefore, it is possible that 49% of the hours could

have occurred outside the specific “shift” category. In another

report, 14.5%, or 14.5 million full-time wage and salary

workers, were categorized as working an “alternate” shift.46

This percentage was reduced from a report 10 years earlier

that found 18% working an alternate shift.46

Shift work has evolved from longstanding views related to

swing- and night-shift work that occurred primarily as a result

of the Industrial Revolution. Historically, electric lighting and

machines made it possible for manufacturing and assembly

line operations to expand into around-the-clock activities.

However, the modern workforce has evolved far beyond these

traditional views of shift work. Box 57–1 identifies some of the

common schedule factors that affect the modern workforce

and that can create sleep and circadian disruption, with

subsequent effects on alertness and safety.

Even a cursory consideration of the factors identified in

Box 57–1 clearly shows that the issues associated with

modern work schedules extend far beyond traditional perspectives. In fact, many occupational settings that would have

never been previously identified as “shift-work” environments

do have to confront the physiologic challenges posed by the

issues in Box 57–1. For this reason, it is unlikely that we

have any accurate or relevant data to determine how many

workers in the United States must confront the known

sleep and circadian disruptions that can be associated with

managing modern work schedules. One poignant example of

this workforce evolution is the extensive amount of air travel

that is now commonplace in many occupational settings.

Whereas traditional “shift work” activities were generally

ground based, the sleep and circadian disruptions associated

with domestic and international travel can have similar

physiologic outcomes. People in the United States take more

than 161 million domestic trips on airplanes every year,

and 47% of these trips are likely to be business or work

related.47,48

No data are available on how many people have work

schedules affected by the factors identified in Box 57–1.

Therefore, there are no reliable estimates of the number of

Americans who experience sleep and circadian disruptions

related to their work schedules. However, some extrapolation

from existing data sources suggests that significantly more

people are affected than generally considered. A 2001

American Work Force report identified approximately 135

million workers in the United States in 2000.49 If roughly 78%

are on a fixed day schedule, then 30 million workers would be

working outside this 9-to-5 day.45 Since only 50% of the work

hours had to fit this category, then the other 50% could have

been outside this fixed day schedule. This could represent

another 53 million workers for a total of 83 million people

who are working outside a standard, fixed day schedule. Of

course, data on who works these schedules regularly, occasionally, or on demand is also unknown.

Any discussion of who is affected by work schedules must

also include the diverse entities that assume the cost of outcomes. Traditionally, discussions regarding shift work focused

on the issues related to the individual worker. However, it is

clear that work schedules affect individuals, employers, and

the public. The primary focus on individuals has typically

been related to health issues, such as increased risk for

gastrointestinal and cardiovascular diseases, reproductive

health problems, and cancer.50-53 The organizational focus is

usually on safety and work hours, and the public interest is

safety for individuals and for society more generally. This is an

expanded and critical perspective because it emphasizes that

the organizational and societal roles in effectively managing

work schedules equals that of the individual. It is this “shared

responsibility” approach that offers an opportunity to bring

disparate entities together for constructive change regarding

these issues rather than deteriorate into finger pointing

and blame. No one entity alone—individual, organization, or

society—can fully or effectively manage the challenges posed

by modern work schedules. The need for a comprehensive

approach that involves shared responsibility is further

highlighted by the complexity of real-world operational

environments.

THERE IS NO MAGIC BULLET

Effectively managing the sleep and circadian disruption associated with work schedules is a complex, and often contentious,

endeavor. Five factors illustrate the complexity of addressing

this issue. First, there are diverse operational requirements

both across work settings and within specific environments.

For example, aviation environments include domestic and

short-haul, international, air cargo, corporate, and on-demand

flying; fixed-wing craft and helicopters; and other flight activities. Second, there are individual differences among the

operators, such as age, experience, and sleep need. Third, sleep

and circadian physiology is complex, as clearly illustrated by

the content of this book. Fourth, historical and cultural factors

affect work schedules; one such factor is the classic attitude,

“that is how I learned it” or “it has always been done that way.”

Box 57–1. Work-Schedule Factors That

Affect Sleep, Circadian Rhythms,

and Alertness

Early start times

Extended work periods

Amount of work time within a shift or duty period

Less than 8 hours off between work periods

Number of consecutive work periods

Insufficient recovery time off between consecutive

work periods

Night work through window of circadian low

Daytime sleep periods

Day-to-night or night-to-day transitions (schedule

stability)

Changing work periods (e.g., starting and ending times, 

cycles)

On-call or reserve status

Schedule predictability (i.e., available in advance)

Time zone changes

Unplanned work extensions

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Managing Work Schedules 683

Fifth, economics can be a powerful consideration for all parties involved in defining work schedules. For individuals, the

work schedule will affect income level, quality of life, and family relations. For the organization, work schedules can define

workforce size and requirements (i.e., fixed personnel costs),

productivity and output, and operational flexibility to meet

changing corporate needs.

Together these five factors demonstrate the complexity

of effectively managing the sleep and circadian disruption

associated with work schedules. This complexity precludes

a simple or single solution or a one-size-fits-all approach to

managing fatigue in operational settings.

To expand further on this real-world complexity, an

Alertness Risk Management (ARM) model based on Reason54

is portrayed in Figures 57–1 to 57–5. It illustrates some examples of the risks associated with different levels of alertness,

the complexity of their interaction, and how, when the factors

coincide, an alertness-related incident or accident can occur.

The initial five factors identified and the expanded risk

examples portrayed in the ARM clearly demonstrate the need

for a comprehensive approach to effectively managing the

sleep and circadian disruptions associated with modern

work schedules. A comprehensive alertness management

program (AMP) to address these issues would include education, alertness strategies, scheduling, healthy sleep, and policies

and scientific foundation.9,55-57 An overview of how to apply

this comprehensive approach to individual, organizational,

and societal issues related to managing work schedules is

outlined next.

ALERTNESS MANAGEMENT

An Individual Perspective

Education

Perhaps the most crucial starting point for individuals is to

become educated about the personal health and safety risks

associated with sleep and circadian disruption. Previous

National Sleep Foundation data have shown that generally

people are uninformed and hold misconceptions about even

the most basic sleep knowledge.58 It is important for individuals to know the basics of sleep need, cumulative sleep debt,

circadian windows of alertness and performance vulnerability,

effects of sleep loss, and more. This knowledge-based education

Society

Regulations

Attitudes/biases

Information

24/7 demand

Safety

Cost v. benefit

Policies

Organizations/Corporations

Economics

Regulations

Programs/activities

Customers

Policies

Personnel

Scheduling

Culture/values

Figure 57–2. Alertness Risk Management (ARM) Model: Risk factors associated with organizations or corporations.

Copyright Alertness Solutions 2004.

Figure 57–1. Alertness Risk Management

(ARM) Model: Risk factors associated with

society. Copyright Alertness Solutions

2004.

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684 Disorders of Chronobiology

should be complemented by a tailored personal identification

of the signs and symptoms experienced as a result of sleep

and circadian disruptions. There is a critical transition from

identifying a sign and symptom to taking action.

Alertness Strategies

A variety of strategies have been empirically studied and shown

to increase alertness and performance. These strategies include

planned naps, caffeine, good sleep habits, managing the sleep

environment, exercise, light and dark exposure, activity breaks,

diet, sedative-hypnotic and stimulant medications, and sleep

scheduling.9,57,59 The effective use of these strategies requires

that individuals understand the specifics of each one—for

example, the length of naps, the doses of caffeine that boost

alertness and the amounts in different drinks and food, what

constitutes good sleep habits versus those that will disrupt

sleep, potential benefits and adverse effects of prescription

medications, and the timing of exposure to light and dark.

Once people are knowledgeable about the effective use of these

alertness strategies, they must take two important implementation steps. First, individuals should test the strategy at home,

outside the work settings, to find out what works best for them.

Second, an “alertness strategies plan” can be developed that

involves proactively determining when and how to use strategies to manage the challenges of a specific work schedule.

Scheduling

Scheduling can be the greatest challenge from an individual

perspective, depending on the amount of control that the

worker has in determining his or her own specific schedule.

The tremendous number of external factors that determine

work needs can leave little individual flexibility in choices.

However, one basic choice available to someone is whether to

work in a particular setting that has schedules that create significant individual disruption. In some cases, especially due to

economic needs, individuals have minimal choices. In some

circumstances, seniority, specific job skills, rotating positions,

and changing corporate requirements do provide choice and

even input to schedule design.

Any work environment has workers with average hours and

those who work less or more. Sleep and circadian rhythm can

be disrupted by considerable overtime, extended hours, minimal

vacation, and other work “opportunities” that can represent

increased income for an individual as well as increased risks

Operations

Scheduling

Mechanical

Unpredictable events

Personnel

Weather Customers

Individual

Circadian rhythms

Continuous wakefulness

Attitudes

Education

Schedules

Sleep disorders

Sleep

Behaviors

Strategies

Figure 57–3. Alertness Risk Management

(ARM) Model: Risk factors associated with

operational demands. Copyright Alertness

Solutions 2004.

Figure 57–4. Alertness Risk Management

(ARM) Model: Risk factors associated

with the individual operator. Copyright

Alertness Solutions 2004.

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Managing Work Schedules 685

people can be overwhelmed by the claims for an “easy fix” or

the latest “cure.” Each claim should be examined or

researched for appropriate scientific data that substantiate its

safety and effectiveness.

Family and Support Network

Persons managing the challenges of work schedules should

incorporate family and friends into a support network that

provides another asset for their efforts. This could take the

form of family education about sleep and circadian rhythms,

participation in planning alertness strategies, or support in

protecting an identified sleep opportunity. Rather than only

viewed as another “stress” associated with challenging

work schedules, family and friends can be another asset for

effectively managing schedules.

An Organizational Perspective

Education

The most important foundation for any alertness management

program is education. This education should be provided

to everyone in the organization. Although there is a natural

tendency to focus on the operational personnel (e.g., drivers,

pilots, officers, nurses), it is critical that all members of the

organization share a common knowledge and appreciation for

the health and safety issues associated with work schedules.

This provides a shared information base among operational

personnel, managers, schedulers, and other employees who

are either affected by or have an effect on work schedules. The

alertness management education activities should be implemented through different corporate forums and in varied

formats. Programs viewed as just another “safety issue of the

month” will have little substantial effect on individual behavior

or corporate activities. The organization must determine whether

this education is voluntary or required and what evaluation

to alertness, health, and safety. Shared responsibility is critical:

An individual worker can seek every opportunity to increase

work hours and income, and an organization or corporation

can limit these opportunities in order to reduce potential health

and safety risks. Conversely, in busy or emergency situations,

individuals who are willing to work beyond schedule requirements can represent a significant resource for a corporation.

Healthy Sleep

This text outlines the prevalence, signs and symptoms, diagnosis, and treatment of known sleep disorders. Primary symptoms of these disorders include disturbed sleep and increased

waking sleepiness, with subsequent effects on performance,

health, and safety. In spite of their prevalence, many of these

sleep disorders are undiagnosed or misdiagnosed. Therefore,

many individuals have existing, undiagnosed sleep disorders

known to affect waking alertness and performance. The associated signs and symptoms of these disorders are exacerbated

when these individuals work schedules that further disrupt

their sleep and circadian rhythms. It is critical that individuals

learn about potential sleep disorders that may affect them and

seek help from accredited sleep medicine professionals to

identify and treat underlying causes of sleepiness.

Policies and Scientific Foundation

Individuals should seek information on appropriate policies

that affect these alertness-management issues. For example,

are there corporate policies on the use of planned naps or how

work status is affected for employees with sleep apnea? Without

explicit policies in these alertness-management areas, employees may hesitate to use strategies or seek diagnosis and treatment. It also is important that individuals use information

and strategies that have a known scientific foundation. When

exploring sleep, sleep disorders, alertness, and work schedules,

Individual

Society

Organizations/

Corporations

Operations

24/7 demand

Scheduling

Unpredictable

Sleep disorders

Figure 57–5. Alertness Risk

Management (ARM) Model: An

accident or incident can occur

when the risk factors “line up.”

Copyright Alertness Solutions 2004.

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686 Disorders of Chronobiology

mechanisms might be used to assess the effectiveness of the

educational activities.

Alertness Strategies

Several activities related to alertness strategies require corporate attention. The organization must identify alertness strategies that it explicitly supports and intends to implement.

Once identified, these strategies should be visibly supported

through appropriate policies or other actions. For example, if

planned naps are encouraged during breaks or prior to a

commute home, are there appropriate facilities to support

this strategy? If adjusting light levels in certain operational

environments is part of a corporate strategy, defining responsibility for facility changes and oversight is critical. It is important that corporations determine any relevant federal or

industry policies that affect organizational efforts. Any disconnection or conflict among policies can undermine efforts

to implement corporate alertness strategies.

Scheduling

Organizations can assess their output or operational needs as

a determining factor for designing work schedules. This can

lead to identifying personnel requirements, coverage needs,

productivity objectives, and so on.

An organization has a range of work schedule options available to consider for meeting its identified needs. These options

include fixed schedules and rotation shifts. Fixed schedules

include permanent day, evening, and night shifts. Rotating

shifts can rotate fast or slow and forward or backward (day,

swing/evening, night or night, swing/evening, day). It is critical that an organization examine the full range of scheduling

factors that can affect sleep and circadian physiology. Often the

emphasis is on the duty or shift length (8 or 10 or 12 hours).

Although shift length is one important factor that can affect

fatigue and safety, many more factors also should be considered

in designing the schedule. A list of some core work-schedule

factors are presented in Box 57–2.

These schedule-design factors, while not all-inclusive, do

demonstrate that sleep and circadian physiology are affected

by much more than just how long an employee is on duty. The

complexity and challenges of designing a schedule is fully

illustrated when considering how to merge organizational

requirements with these core schedule factors that can affect

sleep and circadian rhythms.

Healthy Sleep

Undiagnosed sleep disorders represent significant health and

safety risks for corporations. At a minimum, corporations

should provide information about the signs and symptoms of

sleep disorders, assistance in locating accredited sleep medicine professionals, and help in determining health insurance

coverage for evaluation and treatment. More direct and significant benefits can be obtained by having the corporation

support healthy sleep activities. For example, a corporate

health promotion program that focuses on sleep apnea can

provide individual as well as organizational health and safety

benefits. A corporation should determine what activities

might be voluntary and which operational personnel would

benefit from focused efforts. For these activities to succeed, it is

critical that explicit corporate policies be determined and

communicated. These organizational policies should be consistent with federal regulations and industry standards.

Policies and Scientific Foundation

As described in the sections on alertness strategies and

healthy sleep, any aspect of a corporation’s AMP that can be

supported with explicit policies should be. If alertness management activities are unclear, unsupported, or interpreted as

potentially negatively affecting personnel, there will be little

progress toward change. However, clear policies that are communicated broadly and visibly supported will provide tremendous support for a corporation’s AMP. It may be that areas of

a corporation’s AMP will require the corporation to develop a

policy because none currently exists. This represents an

opportunity to be proactive and potentially create best practices that could lead to industry standards.

It is also critical that a corporation’s AMP be based on

appropriate scientific data where appropriate. To determine

what program elements to implement, management can refer

to neutral and objective scientific data. However, it is also

crucial to acknowledge that data do not exist to address every

operational environment or contingency. Therefore, scientific

knowledge can be used to guide operational decisions and

actions but may not always address the specific issue in

question.

Family and Support Network

Corporations should consider mechanisms that extend the

organizational activities into the home. Providing AMP activities that involve family and friends will support individual

efforts to engage these networks as an asset in managing work

schedules. These activities can include education events, outreach efforts, and corporate communications. Some of the

benefits of these activities are clear: Consider the opportunity

to have family informed of the signs and symptoms of

sleep disorders (e.g., snoring) and their role in encouraging

diagnosis and treatment.

A Societal Perspective

Education

Significant progress has been made in providing health information on the importance of diet, exercise, smoking, and

other issues, but education on sleep, circadian rhythms, and

Box 57–2. Factors in Work Schedule Design

Minimum opportunity for rest or off-duty sleep

Shift length

Work time within duty period

Consecutive work days

Recovery opportunities

Work cycles of days on and days off

Duty time of day versus night

Start and end times of duty periods

Day-to-night duty transitions

Overtime or extended-duty periods

On-call or reserve status and procedures

Duty and recovery opportunities over extended periods

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sleep disorders severely lags behind. For society to benefit

from the already extensive knowledge available in these areas,

an explicit effort must be made to integrate activities into all

levels of the education system. These efforts should support

alertness-education efforts in all aspects of society, beyond

formal educational institutions to work settings and all

relevant settings confronted by these issues.

Alertness Strategies

Strategies known to effectively promote alertness and performance should be supported and explicitly encouraged.

Societal acknowledgment and clear encouragement for

addressing work-schedule issues will provide sanctions and

permission to overtly engage alertness strategies.

Scheduling

A challenging problem confronts modern society: Aroundthe-clock activities bust be conducted in a safe and productive

manner. It would be heresy to consider ceasing night or

around-the-clock operations given modern society’s reliance

on these activities for the most basic of requirements. Yet the

health and safety risks posed by these work schedules are not

fully appreciated and certainly not widely addressed in

occupational settings. However, this disconnection between

need, acknowledgement, and action results in significant

societal costs to health and safety for individuals, organizations, and society. Future efforts can focus on aligning societal needs with managing work schedules that will promote

alertness, health, and safety in the context of around-the-clock

operational requirements.

Healthy Sleep

Like education and alertness strategies, healthy sleep is

another area where a societal priority needs to be established

that will promote the diagnosis and treatment of sleep

disorders. All aspects of this issue should be addressed, for

example, educating health care providers, providing insurance

coverage for diagnostic procedures and treatment, developing

new treatment approaches, conducting research to determine

the most effective treatments, and pursuing innovative

activities that will identify and treat the significant numbers of

undiagnosed individuals.

Policies and Scientific Foundation

Extensive scientific knowledge currently exists regarding the

health and safety issues related to managing work schedules.

This scientific knowledge can lead societal change, as it has

in many other health-related areas, and should be a guide for

the specific actions undertaken. Knowledge gaps should be

addressed by appropriate research, although application of

the formidable existing scientific literature should be a priority. Wherever possible, explicit policies that support alertness

management activities and cultural change should be established, visibly enacted, and integrated into ongoing aroundthe-clock operations. At some point, society will have to

confront the liability issues (broadly defined) associated with

the work schedules currently required by around-the-clock

demands.

ONGOING SCIENTIFIC

AND OPERATIONAL

CONSIDERATIONS

There is extensive scientific information available to guide

effective management of work schedules, but many remaining

relevant issues have received minimal attention. The following

examples of these ongoing considerations demonstrate the

need for further research and operational evaluation of these

diverse issues.

Compressed Schedules

The general societal tendency is to compress work schedules

for more time off. Although compressed schedules are attractive to workers as a means for having more “home time,” the

effects on sleep and circadian factors have not been examined.

One example is the “quick change over” used typically at the

end of a work cycle. In a backwards shift rotation there is a

minimum rest period followed by the final duty period of the

cycle. Although this can provide more time off, one study

found an average of 5.1 hours of sleep obtained during the

8 hours off between the quick change.60

Long-Term Effects of Chronic Sleep

Loss and Circadian Disruption

Most studies of work schedules involve either short periods of

study or laboratory simulations. Of course, individuals work

these schedules for months and years over the course of their

lives. Although there are some data on long-term health effects

of shift work, the potential outcomes from chronic sleep

loss and circadian disruption associated with modern work

schedules remain generally unknown.

Prescription Medications

There are two obvious applications for the use of prescription

medications in addressing work schedule issues: promoting

sleep and promoting wakefulness. There are safe, effective

short-acting sedative/hypnotic medications (see Chapter 37)

that can provide improved sleep in challenging circumstances.

For example, workers with day sleep periods or during offduty transitions between schedules could benefit from

increased quantity and quality of sleep by using a prescription

sleep medication. The use of a sleep medication could reduce

the amount of acute sleep loss experienced prior to a work

period. Currently, none of the prescription sleep medications

has an indication for use in managing work schedules or

specifically to treat shift work sleep disorder.

The first U.S. Food and Drug Administration (FDA)-

approved medication for treating shift work sleep disorder is

modafinil, which promotes wakefulness. The product insert

suggests a dose of 200 mg to be taken 1 hour before the start

of the shift. Given the extensive number of work schedule

factors that can affect sleep, circadian rhythms, alertness, and

performance (see Box 57–1 and Box 57–2), a safe, effective

prescription medication that promotes wakefulness could

have beneficial applications in many settings and circumstances.

For example, unforeseen circumstances that extend work

periods, on-call situations, or significant circadian disruption

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688 Disorders of Chronobiology

represent opportunities for a wakefulness-promoting medication to improve alertness and performance.

The issue of using prescription medications to address

sleep and alertness issues related to work schedules is a prime

example of the ongoing scientific and operational considerations that need attention. With the available scientific literature

as a foundation, more clinical research is required to establish

the safety and effectiveness of prescription medications in

operational use. Future research efforts in this area should

reflect actual work scenarios and operational complexity,

so that findings can guide safe, effective, and responsible use

of prescription medications. Appropriate cautions should be

fully acknowledged, and every possible strategy that can

promote alertness, performance, and safety should be given

consideration and, where suitable, used to its full benefit.

Subjective Disconnection

The current scientific literature clearly demonstrates that there

is usually a discrepancy between subjective reports of sleep,

alertness, and performance compared to objective measures.61-63

Generally, people are by objective measures less alert and have

more reduced performance compared to their subjective

report. This is important because people report that their

performance and alertness are better than their actual levels.

This disconnection can inhibit a decision to engage an alertness strategy: “don’t need it, doing fine.” Therefore, the role

of sleep loss and circadian disruption and the effects of fatigue

will be underestimated and workers will be at risk.

Worker as Patient

Most individuals do not perceive their work experience as

making them a patient. There are, of course, many occupational health issues that are known and addressed. However,

although many people are significantly affected by sleep loss

and circadian disruption from the work-schedule factors in

Box 57-1 on a daily basis, few seek intervention for these

issues in the health care system. Of course, many of these

work-related scheduling issues would not be amenable to a

health care intervention. The combination of not perceiving

these factors as health and safety risks and the subjective

disconnection previously described is the primary reason that

workers, organizations, and society continue to be at risk for

incidents, accidents, and illnesses.

Sleep Apnea

Sleep apnea is one example of a well-established health and

safety risk that is generally ignored in occupational settings.

Estimates indicate that of the possible 18 million people with

sleep apnea in the United States, less than 10% to 20% are

identified and treated.32,64 Every day, these individuals suffer

the personal health consequences of not having their sleep

apnea diagnosed, and thus they extend the safety risks to

themselves, their coworkers, and the general public.

Drowsy Driving

The data are overwhelmingly clear that drowsy driving poses a

significant safety risk for society. In particular, drowsy driving

related to work schedules—whether going to work, on the

job, or driving home—deserves to be examined more closely

and addressed. Alertness Solutions surveys have found alarming

levels of drowsy driving on the job: 41% of health care workers reported nodding off while driving and 39% reported a

near-miss or accident due to being tired; 20% of a corporate

fleet reported nodding off and 14% reported a near-miss or

accident; and 45% of police officers reported nodding off and

30% reported a near-miss or accident. These reports were in

relation to driving to and from work and specifically involved

fatigue or being tired. Occupational settings should consider

how work schedules contribute to this significant safety risk

and actions that can lead to improving the safety of its

workforce.

CONCLUSION

Modern work schedules have evolved dramatically from their

roots as traditional shift work to meet historical manufacturing and line operations. There are few data to estimate the

actual number of workers challenged by the sleep and

circadian disruption engendered by the many modern workschedule factors that affect these physiologic systems. Current

data likely underestimate an issue that could affect 30 to 80

million people in the United States. The sleep loss and circadian disruption associated with today’s work schedules create

significant health and safety risks for individuals, organizations, and society. The complexity of these issues is best

addressed through a comprehensive alertness management

approach that involves a shared responsibility among all

stakeholders. This approach can be applied to individuals,

corporations, and society and provide an opportunity to effectively manage the health and safety risks associated with

around-the-clock operations. There remain many challenges

as further data are needed to address known work-schedule

issues and as current scientific knowledge is more extensively

applied to existing risks. Effectively managing modern work

schedules and their associated sleep and circadian factors

offers an opportunity for sleep medicine to improve the health

and safety of millions of workers, corporations, and society.

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