OutlineWhat is shiftwork?

Shiftwork in CanadaWhy there is a need for shiftworkHealth and safety concerns of shiftworkCircadian RhythmOptimal shift schedulingShift work systemsStrategies for dealing with shiftwork

ShiftworkA shift worker is anyone who follows a work schedule

that is outside of the typical "9 to 5" business day National Sleep Foundation

Shiftwork differs from a “normal” work day in two ways:

1)Work is performed regularly during times other than morning and afternoon

2)At a given workplace, more than one shift is worked during the 24-hour day A shift often lasts 8 hours but may be shorter or longer

Approximately 25% of the North American working population work shiftwork

CCOHS stat

Shiftwork in CanadaIn 2005, the General Social Survey conducted

by Statistics Canada found that 28% of employed Canadians (4.1 million workers) were shift workers 82% worked full time (>30 hrs/week)

Shiftwork in CanadaIn 2005, women accounted for only 37% of

full time shift workers, but made up 69% of part time shift workers

Men made up 57% of the total number of workers who do shift work (all full- and part-time)

Shiftwork in Canada

In 2005, rotating shifts and irregular schedules were the most common types of shift work, accounting for 2.3 million full-time workers

Even though these are considered among the most difficult shifts because the body cannot properly adjust to the sleep pattern changes, rotating child care is difficult to find and health effects can be profound

Types of Shiftwork in Canada

Shiftwork is not new!Deliveries were made in ancient Rome at night in

order to relieve street congestionBakers habitually work through the late night

hoursSoldiers and firefighters have always been

accustomed to night shiftsWith industrialization came long working days

with teams of workers relaying each other to maintain blast furnaces, rolling mills, glassworks, and other workplaces where continuous operations were required

Who works shiftworkTraditionally: shift work was required to provide vital services and emergency cover at all hours of the day and night and also to maintain long-term industrial processes

Today: Shiftwork is found in financial and retail services where employees deliver services around the clock , supermarkets, newsroom and banks, call centres

Why the need for shiftwork?The need for "around the- clock" workers has

increased dramatically in industry during recent years

This reliance may be attributed to three main sources, namely technological, economic and social advancementsEconomically: utilization of equipment/resources

If equipment is available 168 h per week and used for only 8h a day for 5 days a week gives only 24% utilization

Socially: convenience (24-hour shopping, restaurants, movies)

Why is shiftwork a problem?The problems associated with shiftwork fall

under three areas:1)Economic: people tend to dislike shiftwork

which may require extra pay for workers2)Social: many workers feel that shiftwork

disrupts their personal and family life3)Health and Safety: Rotating shifts have

been blamed for the “human error” involved with nuclear power plants incidents, airplane accidents, and other catastrophic accidents Individual health factors

“Some of the most serious and persistent problems shift workers face are frequent sleep disturbance and associated excessive sleepiness, which can lead to poor concentration, absenteeism, accidents, errors, injuries, and fatalities. The issue becomes more alarming when you consider that shift workers are often employed in the most dangerous of jobs, such as firefighting, emergency medical services, law enforcement and security”

- National Sleep Foundation

Individual Health and ShiftworkFrequently changing work schedules can lead to:

Shiftwork may also be independent predictor of

Increased risk of insomnia

Chronic fatigueAnxiety and depressionCardiovascular and

gastrointestinal problemsImpaired reproduction in

womenCircadian rhythm

disruption

Increased body massIncreased body mass

indexPrevalence of obesityWaist-to-hip ratio

Atkinson et al. (2008)

Fatigue SymptomsSleepiness

Irritability

Reduced alertness, concentration and memory

Lack of motivation

Increased susceptibility to illness

Depression

Headaches

Giddiness

Loss of appetite and digestive problems

Personal FactorsMany functions of the human body have long

been recognized to exhibit periodic variationsOf concern are those fluctuations which occur

on a daily basis called circadian rhythmsAmong those body functions which show

diurnal variations:SleepReadiness to workautonomic processesheart ratebody temperatureBlood pressure

Circadian Rhythms

Circadian RhythmsCircadian comes from the Latin word

“circa dies” which means “about a day.”

Many human physical functions follow these daily rhythms or 24-25 hour cyclesSleeping, walking, digestion, secretion of

adrenalin, body temperature, blood pressure, pulse, other body functions

The body uses cues from its processes and from the environment such as clock time, social activities, the light/dark cycle, and meal times to keep the various rhythms on track

Circadian RhythmsInvolvement in shiftwork, in particular night

work, results in a disruption of these inherent rhythms.

These phase shifts occur slowly over a considerable period. Some people can start to adapt after 2-3 days while

some take much longer.

Adjustment on “days off” does not happen because most individuals go back to normal day schedules

Circadian Rhythms• Circadian rhythm phase shifts induced by

shiftwork can have significant effects on the worker in terms of:

• performance efficiency• motivation• sleep patterns• family and social life• health

Shiftwork DisorderShift work sleep disorder is a circadian

rhythm sleep disorderThe main complaint for people with shift

work sleep disorder is excessive sleepiness. Other symptoms include:Insomnia Disrupted sleep schedules Reduced performance Difficulties with personal relationships Irritability/depressed mood

Circadian TypeThere are 2 broad classifications of

personality associated with circadian type which are differentiated between the “morning larks” and the “night owls”:

1)Morning types (M-types) aka larks: Have early bedtimes & wake times and

are more alert in the morning hours

2)Evening types (E-types) aka owls:Are more aroused later at night and

experience difficulty waking up early

M-types have been found to be less tolerant of night shift for 3 reasons:

1.They find it extremely hard to stay awake at night, or to sleep late in the morning (standard night worker behaviors)

2.They appear to be more susceptible to environmental zeitgebers (time cues)

3.When M-types are isolated from all time cues, they exhibit "free-running" circadian rhythms with an approximate length of 24.3 hours in comparison to E-types who tend to have slower rhythms of approximately 25.5 hours

Circadian Type & Shiftwork

Night work is best suited to those individuals with a longer running period as this leads to a phase delay in behaviour (i.e.- a later bedtime)

It has been questioned whether morningness-eveningness is a stable, genetically determined trait, or simply a reflection of a recently developed habitExample: An M-type individual could temporarily

acquire E-type characteristics, but may revert back to their morningness tendency at a later stage

Circadian Type & Shiftwork

What is the most optimal shift schedule?1) There is no “golden” schedule that fits every

operation’s needs

2) The schedules that perform the best:1) balances operational requirements, employee

preferences and lifestyle issues, and takes into account the human factors considerations that influence safety and employee performance

3) The best schedules can only be achieved by involving the employees in the shift schedule selection process

Why involve employees in shiftwork scheduling? Through education, participatory design, and group

implementation of employee involvement in schedule design/redesign financial and performance benefits increase substantially compared to schedules decided by management alone

Resulting in:Better employee morale and satisfaction with

schedulingLower absenteeism and turnoverIncreased operational efficiency Improved daytime sleep qualityDecreased physical and

psychological circadian

General Notes on SchedulingAn early morning start (before 7:00am) for

the morning shift should be avoided

Shifts should rotate forward:

The schedule should be simple and predictable – people want to plan their lives!

Four Important Questions Regarding the Features of Shift Systems1. Does a shift extend into hours that would be

normally be spent asleep?2. Is the shift worked throughout the entire

seven-day week, or does it include days of rest, such as a free weekend?

3. Into how many shifts are the daily work hours divided? Are there two, three, or more shifts per day?

4. Do the shift crews rotate or do they work the same shifts permanently?

Kogi (1985)

Other Important Features of Shift Systems

The starting and ending time of a shiftThe number of workdays in each weekThe hours of work in each weekThe number of shift teamsThe number of free days per week or per

rotation cycleThe number of consecutive days on the same

shift, which may be a fixed or variable numberThe schedule by which an individual works or

has a free day or days

Types of Shift SystemsRotational shiftworkRapidly rotating shift systemsweekly/monthly rotating systemsPermanent night shift systems

Shifts rotate or change according to a set schedule

Shifts can be continuous (24/7) or semi-continuous (2-3 shifts/day without weekends)

Workers take turns working all of the shifts in the system

Rotational Shiftwork

Rapidly Rotating SystemsSwitches once or twice during a week

Found to cause the least disturbance to the endogenous body clock

Weekly/Monthly Rotating Systems

Changes every week or every month• Provide for both the physical and social

needs of the workerA forward direction

(morning-afternoon/evening-night) is preferred for shift rotation• Means minimum disturbance of diurnal

rhythms

Weekly/Monthly Rotating Systems

Weekly rotating shifts are generally regarded as being the worst system • Because disruptions to the circadian

rhythms lead to a cumulative sleep debt• These systems tend to be the most

commonly used (employment equity)

Permanent Night Shift SystemAn acceptable level of circadian rhythm

adjustment can normally be achieved with this shift systemThis nocturnal orientation may in turn

improve sleep and performancePermanent night shifts are preferred

when safety is crucial

Permanent Night Shift SystemFamily units appear to prefer permanent

night work as it facilitates the organization of domestic responsibilities

Some individuals working this shift feel socially isolated

Extended WorkdaysOne further variable to consider in terms

of the design of shift systems is that of the length of the shift

Some suggest a shift should not exceed 8 hours (except where the work is low in physical and mental demands) while others recommended that extended work periods of 9 to 12 hours may be acceptable

Advantages of twelve hour shifts Management Perspective

Employee Perspective

Increased productivity, reduced errors

Increased continuity and accountability

Reduced adaptation timeHigher project

completion ratesReduced absenteeism Lower attrition and

turnoverImproved morale“Dedicated” employees

More days offLonger/better breaksFew consecutive days workedLess commuting requiredTwice as many weekends off Improved family & social life Improved MoraleMore home study timeMore frequent “recovery” daysBetter use of vacation timeBetter utilization of personal

timeElimination of double

shifts/holdoversElimination of evening shifts

Disadvantages of 12 Hour ShiftsManagement Perspective

Employee PerspectiveHarder to sustain vigilance

Potential comprise in alertness and performance

Increased exposure to work-related stress

Diminished communication or personal interaction

Unequal distribution of work hours

Increased risk of getting “out of touch”

Increased “moonlighting” Increased ergonomic riskMore difficult absence

coverageDifficulties of change

Limited social time during work days

Sleep schedule inflexibility Irregular pay weeksConcerns of older workersReduced tolerance of long

commutesDifficult to schedule meetingsDecreased tolerance to physically

demanding jobsPay loss when day is missedDriver fatigueFast-rotating 12-hour schedulesLonger hours away from home in

evenings Increased percentage of night

shifts

Summary of Features for 8 and 12-Hour Shift Schedule

Strategies for Improving Problems Associated with ShiftworkMost obvious solution?There are two basic levels where

improvements can be made: 1)The organizational level - primarily through

the design of shift schedules, education and better facilities.

2)The individual level - helping workers to get better sleep, a healthier diet, and the reduction of stress.

Organizational Approaches Talk to employees to see shift preferencesConsider time at which shift starts/endsProvide time off during socially advantages

timesLet employees know schedules well in

advanceAllow some flexibility for staff to switch

shifts but make sure people aren’t double-shifting

Provide same facilities & support for all shifts

Organizational ApproachesEducate employees on how to cope with

shiftworkConsider exposure limits, breaks requiredConsider different lengths for shiftsKeep schedule regular and predictableKeep long shifts and overtime to a

minimumPlan for some weekends or holidays off

Good Practice Guidelines for the Work EnvironmentAdequate lighting & proper heatingSame facilities available for each shiftAccess to healthy mealsEncourage interaction between employeesKeep in contact about employees about

their concernsEncourage exerciseEncourage breaks when sleepy

Individual Approaches

Pay attention to food/nutritionExerciseFigure out how to optimize sleep timeGet information on shiftwork health risksHave a social lifeSeek advice from doctor if you have

health conditionsTake more frequent breaks when fatigued

Individual ApproachesTalk to family and friends about sleep

scheduleRestrict or avoid caffeine, cigarettes and

alcohol consumptionAvoid long commutes when sleepyUse co-workers to keep you awake on the jobTalk to co-workers for tips on how to copeDon’t leave the boring tasks for the end of

the shift when most fatiguedTry not to alter sleep schedule too much on

“days off”

References: Atkinson, G., Fulick, S., Grindey, C., & Maclaren, D. (2008). Exercise, energy balance

and the shift worker. Sports Medicine, 38(8), 671-685. Canadian Centre for Occupational Health and Safety. (2007). Rotational Shiftwork.

Retreived from: http://www.ccohs.ca/oshanswers/ergonomics/shiftwrk.html Carex Canada. (2008) Carcinogen profile: Shiftwork. IARC Monograph, 98. Retrieved

from: http://www.carexcanada.ca/en/shiftwork.pdf Davis, W., & Aguirre, A. (n.d). Shift scheduling and employee involvement: the key to

successful schedules. Retrieved from: http:// www.circadian.com The National Sleep Foundation. (2009). Shift work and sleep. Retrieved from:

http://www.sleepfoundation.org/ Konz, S., & Johnson, S.(2000). Work Design: Industrial Ergonomics. Scottsdale, Az:

Holcomb Hathaway. Kroemer, K., Kroemer, H., & Kroemer-Elbert, K. (2001). Ergonomics: How to design

for ease and efficiency (2nd ed.). Upper Saddle River, NJ: Prentice Hall. Moore-Ede, M., Davis, W., & Sirois, W. (n.d). Advantages and Disadvantages of

twelve-hour shifts: A balanced perspective. Retrieved from: http://www.circadian.com Occupational Safety and Health Branch, Labour Department.(n.d) Guide on

shiftwork. Retrieved from: http://www.labour.gov.hk/eng/public/oh/ShiftWork.pdf Williams, C. (2008) Work-life balance of shift workers. Statistics Canada Catologue

number (75-001-X). http://www.statcan.gc.ca/pub/75-001-x/2008108/pdf/5215218-eng.pdf