ArticlePDF AvailableLiterature Review

“A Hard Day's Night?” The Effects of Compressed Working Week Interventions on the Health and Work-Life Balance of Shift Workers: A Systematic Review

Authors:

Abstract and Figures

To systematically review studies of the effects of the Compressed Working Week on the health and work-life balance of shift workers, and to identify any differential impacts by socio-economic group. Systematic review. Following QUORUM guidelines, published or unpublished experimental and quasi-experimental studies were identified. Data were sourced from 27 electronic databases, websites, bibliographies, and expert contacts. Fourty observational studies were found. The majority of studies only measured self-reported outcomes and the methodological quality of the included studies was not very high. Interventions did not always improve the health of shift workers, but in the five prospective studies with a control group, there were no detrimental effects on self-reported health. However, work-life balance was generally improved. No studies reported differential impacts by socio-economic group; however, most of the studies were conducted on homogeneous populations. This review suggests that the Compressed Working Week can improve work-life balance, and that it may do so with a low risk of adverse health or organisational effects. However, better designed studies that measure objective health outcomes are needed.
Content may be subject to copyright.
Durham Research Online
Deposited in DRO:
09 January 2009
Version of attached file:
Published Version
Peer-review status of attached file:
Peer-reviewed
Citation for published item:
Bambra, C. and Whitehead, M. and Sowden, A. and Akers, J. and Petticrew, M. (2008) ”A hard day’s
night ?’ the effects of Compressed Working Week interventions on the health and work-life balance of shift
workers: a systematic review.’, Journal of epidemiology and community health., 62 (9). pp. 764-777.
Further information on publisher’s website:
http://dx.doi.org/10.1136/jech.2007.067249
Use policy
The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or
charge, for personal research or study, educational, or not-for-profit purposes provided that:
a full bibliographic reference is made to the original source
alink is made to the metadata record in DRO
the full-text is not changed in any way
The full-text must not be sold in any format or medium without the formal permission of the copyright holders.
Please consult the full DRO policy for further details.
Durham University Library, Stockton Road, Durham DH1 3LY, United Kingdom
Tel : +44 (0)191 334 3042 — Fax : +44 (0)191 334 2971
http://dro.dur.ac.uk
2
Durham Research Online
Deposited in DRO:
20 November 2009
Peer-review status:
Peer-reviewed
Publication status of attached file:
Published version
Citation for published item:
Bambra, C. and Whitehead, M. and Sowden, A. and Akers, J. and Petticrew, M. (2008), 'A
hard day's night ?' the effects of Compressed Working Week interventions on the health and
work-life balance of shift workers: a systematic review.’, Journal of epidemiology and
community health, 62 (9), pp. 764-777.
Further information on publisher’s website:
http://dx.doi.org/10.1136/jech.2007.067249
Use policy
The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior
permission or charge, for personal research or study, educational, or not-for-profit purposes provided that :
a full bibliographic reference is made to the original source
a link is made to the metadata record in DRO
the full-text is not changed in any way
The full-text must not be sold in any format or medium without the formal permission of the copyright holders.
Please consult the full DRO policy for further details.
Durham University Library, Stockton Road, Durham DH1 3LY, United Kingdom
Tel : +44 (0)191 334 2975 | Fax : +44 (0)191 334 2971
http://dro.dur.ac.uk
‘‘A hard day’s night?’’ The effects of Compressed
Working Week interventions on the health and work-
life balance of shift workers: a systematic review
C Bambra,
1
M Whitehead,
2
A Sowden,
3
J Akers,
3
M Petticrew
4
cAdditional appendices and
tables are published online only
at http://jech.bmj.com/content/
vol62/issue9
1
Department of Geography,
Durham University, Durham, UK;
2
Division of Public Health,
University of Liverpool, Liverpool,
UK;
3
Centre for Reviews and
Dissemination (CRD), University
of York, York, UK;
4
MRC Social
and Public Health Sciences Unit,
Glasgow, Glasgow, UK
Correspondence to:
Dr C Bambra, Department of
Geography, Wolfson Research
Institute, Durham University
Queen’s Campus, Stockton on
Tees TS17 6BH, UK;
clare.bambra@durham.ac.uk
Accepted 28 October 2007
ABSTRACT
Objective: To systematically review studies of the
effects of the Compressed Working Week on the health
and work-life balance of shift workers, and to identify any
differential impacts by socio-economic group.
Methods: Systematic review. Following QUORUM
guidelines, published or unpublished experimental and
quasi-experimental studies were identified. Data were
sourced from 27 electronic databases, websites, biblio-
graphies, and expert contacts.
Results: Fourty observational studies were found. The
majority of studies only measured self-reported outcomes
and the methodological quality of the included studies
was not very high. Interventions did not always improve
the health of shift workers, but in the five prospective
studies with a control group, there were no detrimental
effects on self-reported health. However, work-life
balance was generally improved. No studies reported
differential impacts by socio-economic group; however,
most of the studies were conducted on homogeneous
populations.
Conclusion: This review suggests that the Compressed
Working Week can improve work-life balance, and that it
may do so with a low risk of adverse health or
organisational effects. However, better designed studies
that measure objective health outcomes are needed.
Work has long been acknowledged as an important
social determinant of health and health inequal-
ities.
1–4
Employment, or lack of it, and its quality
and type are vital in terms of income and social
status in all advanced industrialised societies.
However, the nature of work has altered consider-
ably over the past two decades, not least in terms
of the cultivation of labour market practices in
which skills, working hours, contracts, conditions,
pay and location are more flexible.
56
Similarly, a
24-hour society has started to emerge with
associated concerns about abnormal working hours
and work-life balance (WLB).
7
In this context, recent reports from the UK
Department of Health and Department of Work
and Pensions, the US Department of Health and
Human Services, and the World Health
Organization show that the workplace is increas-
ingly being considered by policymakers as an
important intervention point at which health can
be improved and health inequalities reduced.
4 8–11
Attention to date has focused on the psychosocial
work environment, in particular psychological
demands and job control (individual decision
authority), as explored in depth in the Whitehall
studies.
12–16
However, there is a largely untapped
literature on the effects of particular types of work
patterning on health and health inequalities, and,
in particular, there is a large body of evidence
spanning several decades that describes the nega-
tive effects of shift work on health and well-
being.
17 18
Reported health problems associated with shift
work include sleep disturbances, fatigue, digestive
problems, and stress-related illnesses, as well as
increases in general morbidity, and in sickness
absence.
9
These health problems may derive from
disruption to physiological, psychological and social
circadian rhythms,
17 18
as shift work, particularly
that involving night work, disrupts the natural
circadian rhythm, leading to disruption of sleep (as
natural alerting mechanisms such as the cortisol
surge and temperature rise will interrupt sleep) and
daytime functioning (wakefulness at night will be
reduced by temperature drops and melatonin
surges). Sudden changes in schedule can, therefore,
have an effect akin to ‘‘jet lag’’. Disruption to the
circadian rhythm can also lead to disharmony within
the body as some functions (e.g. heart rate) adapt
more quickly than others (typically endogenous
functions such as body temperature, and melato-
nin).
18
This leads to desynchronisation, which itself
can result in psychological malaise, fatigue and
gastrointestinal problems. Realignment can take
several weeks.
18
Most existing research emphasises
these physiological changes, but shift work also
involves significant social desynchronisation, invol-
ving working at times and on days that may make it
difficult to maintain a balanced domestic and social
life work life balance (WLB).
20
Literature also
suggests that cardiovascular problems such as
hypertension and heart disease may be related to
shift work.
21
It has also been suggested that shift
work is associated with breast cancer, (possibly due
to circadian disruption) and the birth of pre-term
(premature) babies, but the current evidence base is
inconclusive.
22–25
Shift work may also involve
increased risk of injuries and accidents as perfor-
mance fluctuates.
26
Shift work may, therefore, be an important, but
largely overlooked determinant of health and
wellbeing for many workers. The practice is
common with one in five European workers
involved in shift work,
25
though the definition of
the term can be complex (the UK Labour Force
Survey for example identifies ten different cate-
gories).
27
Shift work is also socially patterned, being
less common in graduates, and more common
amongst manual workers and those working in the
manufacturing or healthcare sectors.
27
Review
764 J Epidemiol Community Health 2008;62:764–777. doi:10.1136/jech.2007.067249
on 5 November 2009 jech.bmj.comDownloaded from
Changes to the organisation of shift work have the potential
to reduce these negative health effects and perhaps also have an
impact on social inequalities in health and wellbeing. A popular
organisational level intervention is changing the hours of shift
work by introducing a Compressed Working Week (CWW). The
CWW is an alternative work schedule in which the hours
worked per day are increased, whilst the days worked are
decreased in order to work the standard number of weekly
hours in less than five days.
28
The CWW, therefore, represents a
radical break from the 8-hour working day length favoured by
workers and trade unions.
27
However, a cap still remains on the
number of hours worked per week (a maximum of 48 hours
under the European Union Working Time Directive).
27
The
most popular forms of CWW are the 12-hour CWW, the 10-
hour CWW and the Ottawa system.
18
The 12-hour CWW
involves four 12-hour shifts (day, night) over four days with
three or four days off. Under a 10-hour CWW, four 10-hour
shifts are worked followed by three days off. The Ottawa
system consists of three or four 10-hour morning or afternoon
shifts spread over four days, then two days off. This is followed
by a block of seven eight-hour nights, then six days off.
In this paper, we present the results of the first systematic
review of primary empirical studies on the health and WLB
effects of changes to the organisation and experience of shift
work brought about by CWW interventions, and any differ-
ential impacts by social group. Although previous literature
reviews of the CWW exist, these concentrate on observational
epidemiological (descriptive or comparative) studies rather than
evaluative intervention studies, and have not been conducted
using full systematic review methodology.
719 29
METHODS
Inclusion and exclusion
We sought to identify all empirical studies (both prospective
and retrospective, with or without control groups) that
examined the effects of CWW interventions on the health and
WLB of shift workers and their families. For the purposes of the
review, shift work was defined as ‘‘any regularly taken
employment outside the hours of 07:00 and 18:00’’.
18
Interventions had to be implemented in actual workplaces, so
non-workplace laboratory-based studies were excluded. Health-
related outcomes included specific diseases, as well as more
general measures of physical or psychological health and
wellbeing. Sickness absence, health behaviours and injuries
resulting from workplace accidents were included, as were
physiological measures, and measures of physical and mental
wellbeing such as tiredness, fatigue and sleep.
22
The social
impacts of the interventions, specifically on WLB were also
examined. Organisational effects (eg job satisfaction, individual
or organisational performance), when reported alongside the
primary outcomes (health and WLB), were also recorded to help
in understanding the motivations behind the CWW interven-
tions, and also their viability. Impacts on inequalities in health
were considered as outcomes.
Search strategy
We searched 27 electronic databases and websites for docu-
ments of any type, from any country, at any time and in any
language. Details of the databases searched and an example
search for MEDLINE are detailed in boxes 1 and 2. The full
search strategy is available online (Appendix 1). We also
searched bibliographies and reference lists.
Data extraction
We located 13 308 titles, of which 419 were examined in more
detail, and of these 88 were retrieved for full-paper analysis.
The lead reviewer (CB) excluded obviously irrelevant titles and
abstracts from the initial literature search, and retrieved full-
text copies of the remainder. Studies making any reference to
health or wellbeing were independently appraised by two
reviewers (CB and MP), who re-examined papers jointly to
resolve disagreements. We included percentages, confidence
intervals (CI), p values, and effect sizes when they were
reported in the original study, or calculated these statistics
(using final sample sizes) if sufficient information was
available (although lack of data was a problem in some
studies).
Critical appraisal
Critical appraisal criteria were adapted from existing systematic
reviews of the health effects of employment interventions and,
guidance for the evaluation of non-randomised studies (box
3).
30–32
Two reviewers (CB and MP) independently appraised the
included studies according to these criteria.
33
The critical
appraisal criteria were used for descriptive purposes only and
to highlight variations in the quality of studies (see tables 1–3).
No quality score was calculated.
These criteria were used to appraise all of the included
studies. The results of this process are presented under the
critical appraisal section of the results in tables 1–3, with the
Box 1 Databases and websites
The following 27 databases and websites were searched from
start date to November 2005:
cASSIA (CSA)
cEU Community Research & Development Information Service
cDissertation Abstracts
cEric (CSA)
cEuropean Commission Libraries Catalogue
cEconlit (Webspirs)
cElectronic Collections Online (FirstSearch)
cEmbase (Ovid)
cGeobase (FirstSearch)
cHarvard Business Review
cHMIC (OVID)
cIndex to Theses
cInternational Bibliography of the Social Sciences (OVID)
cJSTOR
cLabordoc
cManagement Contents (Dialog)
cMedline (Ovid)
cMedline In-Process & Other Non-Indexed Citations (OVID)
cNTIS
cPAIS (Webspirs)
cPapersFirst (FirstSearch)
cPsycINFO (Ovid)
cREGARD (ESRC)
cResearch Papers in Economics
cSocial Science Citation Index (Web of Science)
cSigle (Webspirs)
cSociological Abstracts (CSA)
Review
J Epidemiol Community Health 2008;62:764–777. doi:10.1136/jech.2007.067249 765
on 5 November 2009 jech.bmj.comDownloaded from
numbers 1–10 representing satisfactory fulfilment of the
corresponding criterion.
RESULTS
Forty studies examined the effects of CWW interventions on
the health and WLB of shift workers.
34–83
The majority of CWW
studies examined changes to four days of 12-hour shifts,
although four examined changes to 10-hour shifts,
34 35 56–59 61
and two examined the introduction of the Ottawa shift
system.
37 78
Twenty-three of the studies were prospective
cohorts,
34–61
of which five were controlled.
34–39
In this paper,
we focus our detailed comments on the results of these better-
designed studies (that is, the prospective cohorts with control
groups), although the overall synthesis reflects the results of all
40 studies. Most of the CWW studies were based in one of four
distinct occupational settings: healthcare organisations (9), the
police force (8), manufacturing companies (11) or energy
industries (9). No studies were found relating to other key
shift-working occupations, such as retail or entertainment.
26
The majority of health outcomes, and all WLB ones, were self-
reported. In a sizeable number of the CWW studies, the
intervention was either at the behest of the work force,
34–
36 41 47 49 60 69 70 83
or from the management (with a stated desire
to improve health or WLB).
37 50 62–64 66 71 74 79 80 82
However, in
other studies, the motivation was more obviously efficiency or
productivity.
46 48 51 53 54 59 61 67 77 78 81
Results are summarised by
study design in tables 1–3 and detailed results are available
online (Appendix 2).
Health-related outcomes
The effects of the CWW interventions on health outcomes
were not conclusive: a number of studies reported some
improvements in workforce health,
34–38 42–45 47–50 52 54 56–60 62–
65 67 68 72–74 78–83
whilst others found no change,
39 40 46 53 55 66 69–
71 75 76 77
and two found only negative effects.
41 51
The five prospective cohort studies with control groups
34–39
found that there were no detrimental effects on self-reported
health-related outcomes after the introduction of CWW
(table 1), and in four of the studies some improvements were
recorded.
34–38
In one Canadian study of 30 police officers,
34 35
self-reported health behaviour in the form of sporting activities
improved in the intervention group compared with the control
group (intervention mean 8.1 to 13.9, comparison mean 7.9 to
7.0, F = 8.8, p,0.01), but sickness absence rates did not change
significantly. In another study of 70 UK police officers,
37
all but
one (sleep quality) of the self-reported health indicators
improved significantly in the intervention group (e.g. for the
General Health Questionnaire scores, the intervention mean
improved from 11.2 to 7.1, whereas the comparison mean
worsened from 11.0 to 11.9, F = 15.56, p,0.001). However, our
critical appraisal of this study identified notable differences in
health at baseline between the control and intervention groups:
the intervention group had a better baseline score than the
control group, thereby possibly leading to an exaggerated
intervention effect.
In a Swedish study of 46 chemical plant workers,
38
self-
reported sleep quality was generally better in the intervention
Box 2 Example search strategy (MEDLINE)
1. shiftwork$.ti,ab.
2. nightwork$.ti,ab.
3. ((shift or shifts) adj2 (work$
or night$)).ti,ab.
4. (night$ adj2 work$).ti,ab.
5. nightshift$.ti,ab.
6. ((shift or shifts) adj2 (rota$ or
system or systems or
schedule$ or roster$)).ti,ab.
7. ((shift or shifts) adj2 (extend$
or pattern$ or cycle$)).ti,ab.
8. ((shift or shifts) adj2 (evening
or late or early or weekend or
twilight)).ti,ab.
9. (hour$ adj (shift or shifts)).
ti,ab.
10. ((shift or shifts) adj2
(continental or continuous
or turnaround or split)).ti,ab.
11. ((nonstandard or non-standard)
adj2 (work$ or shift or
shifts)).ti,ab.
12. ((unsocia$ or antisocia$ or
anti-socia$) adj2 (work$ or
shift or shifts)).ti,ab.
13. (irregular$ adj2 (work$ or shift
or shifts)).ti,ab.
14. compressed work$.ti,ab.
15. long work$ hour$.ti,ab.
16. (extend$ adj (duty or duties or
work$) adj hour$).ti,ab.
17. overtime.ti,ab.
18. (flextime or flex time or
flexitime or flexi time).ti,ab.
19. (flex$ adj work$).ti,ab.
20. work schedule tolerance/
21. or/1–20
22. exp Legislation/
23. legislat$.ti,ab.
24. (law or laws).ti,ab.
25. work$ time directive.ti,ab.
26. ((eu or europe$) adj3
work$).ti,ab.
27. european union/
28. (european adj (commission
or union)).ti,ab.
29. bright light$.ti,ab.
30. (nap or naps or napped
or napping).ti,ab.
31. clockwise.ti,ab.
32. (reorganis$ or reorganiz$ or
re-organis$ or re-organiz$).
ti,ab.
33. (restructur$ or re-structur$).
ti,ab.
34. (entrain$ or re-entrain$).ti,ab.
35. (countermeasure$ or
surveillance).ti,ab.
36. (reschedul$ or re-schedul$
or redesign$ or
re-design$).ti,ab.
37. ergonomic$.ti,ab.
38. (self help or
selfhelp).ti,ab.
39. (self schedul$ or self
roster$).ti,ab.
40. program development/
41. (coping or cope$).ti,ab.
42. exp counseling/
43. counsel$.ti,ab.
44. empower$.ti,ab.
45. circadian rhythm/
46. circadian.ti,ab.
47. phototherapy/
48. phototherap$.ti,ab.
49. (light treatment
or light
therap$).ti,ab.
50. Melatonin/
51. melatonin$.ti,ab.
52. ((structur$ or organis$ or
organiz$
or management or
managerial) adj3
(chang$ or modif$
or design$
or intervention$)).ti,ab.
53. ((structur$ or organis$ or
organiz$ or management
or managerial) adj3 (impact$
or alter$ or adapt$ or measure$
or strateg$)).ti,ab.
54. ((structur$ or organis$ or
organiz$ or management or
managerial) adj3 (reduc$ or
increas$ or particip$
or $ or train$ or program$)).
ti,ab.
55. ((shift$ or work$ or hour$)
adj3 (chang$ or modif$
or design$ or
intervention$)).ti,ab.
56. ((shift$ or work$ or hour$) adj3
(impact$ or alter$ or adapt$ or
measure$ or manag$ or
strateg$)).ti,ab.
57. ((shift$ or work$ or hour$) adj3
(reduc$ or increas$ or particip$
or educat$ or train$ or
program$)).ti,ab.
58. or/22–57
59. 21 and 58
60. animals/
61. humans/
62. 60 not (60 and 61)
63. 59 not 62
Review
766 J Epidemiol Community Health 2008;62:764–777. doi:10.1136/jech.2007.067249
on 5 November 2009 jech.bmj.comDownloaded from
group, eg mean scores for ‘‘feeling rested when wake up’’
improved in the intervention group (from 4.06 to 4.47) whilst
they worsened in the comparison group (4.38 to 4.23).
However, self-reported changes in fatigue, sufficient levels of
sleep and general health did not differ from the control group at
follow-up. Our critical appraisal of this study
38
queried the
suitability of the control group, and noted a lack of adjustment
for confounders or non-responders (table 1). In a Canadian
study of 85 young male mine workers,
36
self-reported sleep
problems and tiredness showed no difference between the
intervention and control groups; however, levels of sickness
absence decreased substantially (reduction of 73% in the
intervention group compared with only 2% in the control
group), as did the number of accidents (reduction of 69% in the
intervention group compared with only 10% in the control
group). The critical appraisal of this study,
36
though, suggests
that the sample was not representative, the baseline and follow-
up responses were low and that there was a lack of adjustment
for confounders or non-responders (table 1).
In another study,
39
of 45 UK police officers, self-reported
health did not improve: chronic fatigue, physical health and
GHQ-12 (a generic measure of psychological stress) scores did
Table 1 Compressed Working Week: prospective cohort studies with a control group
Study
Design and critical appraisal
(see criteria in box 3) Setting and participants
Summary results
q= improvement Q= worsening
«= little change
Barton-Cunningham, 1981, 1982
34 35
Five-month and six-month follow-ups
Final sample: n = 30 (17 intervention, 13 control)
Critical appraisal: 1479
Police force, Canada
Police officers, majority men
Five eight-hour shifts, two days off
to Four 10-hour shifts, three days off
Sporting activities
Absenteeism
Time spent on domestic chores
Time spent on family matters
Time spent with spouse
Time spent socialising with friends
Job satisfaction
q
«
q
q
q
q
«
Barton-Cunningham, 1989
36
Unspecified follow-up
Final sample: n = 85 (68 intervention, 17 control)
Critical appraisal: 17910
Mine, Canada
Mine operatives and plant operators,
young married males, age,39
Five eight-hour shifts, two days off to
Four 12-hour shifts, four days off
Absence
Accidents
Sleep problems
Tiredness
Family satisfaction
Satisfaction with work
q
q
«
«
«
«
Totterdell & Smith, 1992
37
Six-month follow-up
Final sample: n = 70 (40 intervention, 30 control)
Critical appraisal: 12357910
Police service, UK
Police officers
Seven eight-hour shifts, two days off
to Ottawa system (10-hour days and
eight-hour nights)
GHQ
Lack of sleep
Fatigue
Headaches
Stomach aches
Sleep duration
Stress
Feeling unwell
Irregular meals
Sleep quality
Insufficient time for family
Insufficient time for friends
Insufficient time for social life
Personal life disrupted
Planning social life difficult
Domestic arrangements difficult
Poor relations with family
Not enough free time
Effective at work
Fatigue affects work
q
q*
q*
q*
q*
q*
q*
q*
q*
«
q*
q*
q*
q*
q*
q*
q*
q*
q*
q*
Lowden et al, 1998
38
10-month follow-up Chemical plant, Sweden Easy to fall asleep q
Final sample: n = 46 (32 intervention, 14 control) Plant operators, mainly men Rested when wake up q
Critical appraisal: 12457910 Five eight-hour shifts, three days off to two
or three 12-hour shifts, up to five days off
Sleep quality
Fatigue
Sufficient sleep
General health
Time for social/family activities
Satisfaction with hours
q
«
«
«
q
q
Smith et al, 1998
39
Six-month follow-up Police service, UK Sleep duration (day) q{
Final sample: n = 45 (27 intervention, 18 control) Police officers, mainly men Standard Shiftwork Index Q{
Critical appraisal: 12478910 Fiveorseveneight-hourshifts,twoorthree
days off to site A: flexible starts with four
12-hour shifts, then four days off; or site B:
rigid starts with four 12-hour shifts,
then four days off
Sleep quality (rest)
Standard Shiftwork Index
Chronic fatigue
Standard Shiftwork Index
Physical health
Standard Shiftwork Index
GHQ-12
Workload
Social/domestic interference
Q{
«
«
«
q{
«
Effect sizes have been added to the text where appropriate and the detailed results are available in online table E1.
*There were significant differences between intervention and control groups at baseline.
{Effect disappeared when shift work experience was controlled for.
Review
J Epidemiol Community Health 2008;62:764–777. doi:10.1136/jech.2007.067249 767
on 5 November 2009 jech.bmj.comDownloaded from
not differ between the intervention and the control group at
follow-up, and the significant improvement in sleep duration in
the intervention group disappeared when shift work experience
was taken into account. This study was not notably different
from the others in terms of methodological quality.
Although these studies were robust in terms of study design
(employing control groups), the sample sizes were small,
ranging from 23 to 85, and the lengths of follow-up were
relatively short. No study followed up respondents for at least a
year, which may be the optimum as it allows for the possibility
of controlling for possible seasonal effects. It should also be
noted that three of the five controlled prospective studies were
conducted in the police force and so care is needed in
generalising from these results to other occupational groups
involved in shift work.
The uncontrolled prospective studies (table 2) were also
inconclusive, as, whilst the majority identified an improvement
in one or another of the various health outcomes measured,
they found little effect for other health outcomes.
43–45 49 50 52 54
56–59 62–65 67 68
Amongst the five largest studies (sample sizes
.100),
49 51 59–61
, two reported mixed health effects,
49 59
two
reported health improvements
60 61
and one recorded a negative
health effect.
51
Williams’ study of 131 male chemical plant
workers
49
recorded an improvement in self-reported depression
(decreased from 2.43 to 2.12, t = 2.32, p,0.05), but found no
change in absence and injury rates.
49
Similarly, a study of
Canadian mine workers
59
found that after the introduction of
CWW, sleep (mean difference = 20.3, t = 2.43, p,0.01) and
tiredness (mean difference = 0.9; t = 4.77, p,0.001) worsened
on the day shift whilst gastrointestinal problems (mean
difference = 20.4, t = 2.35, p,0.01) and headaches (mean
difference = 20.3, t = 2.07, p = 0.03) improved. Two studies of
American production workers
60 61
reported various improve-
ments in self-reported health, including a decrease in the
prevalence of common shift-related health disorders (such as
heartburn, acid stomach and diarrhoea) from 43.8% to 27%
(p,0.001)
59
and a decrease in sickness absence (eg from 11.39 to
4.69 days).
61
However, in a study of 150 UK nurses,
51
dissatisfaction with levels of mental (0.8 (0.53 to 1.07)) and
physical (0.7 (0.50 to 0.90)) fatigue increased.
A number of smaller studies of varying methodological
quality and sample size reported no changes in any of the
health indicators.
40 46 53 55 66
Other studies were more conclusive,
finding significant improvements in sleep duration,
42
absence,
47
physiological distress, fatigue and stress,
48
sleep between shifts,
sleep difficulties, and health disorders.
60
In all these stu-
dies,
42 47 48 60
employees were either involved in the design and
implementation of the intervention or they were supportive of
the change. Importantly, only two studies, both based in
healthcare settings, found that all the self-reported measures of
health worsened after the introduction of the CWW.
41 51
Overall, the prospective studies were rather limited in terms
of length of follow-up and sample size: only three studies had
lengths of follow-up of 12 months or more, and the studies were
small (tending to involve 15 to 50 participants).
The pattern was similar for the retrospective studies (table 3),
with only a minority reporting any significant intervention
effect (table 3).
72–74 78–83
The majority of the significant effects,
though, were positive, particularly in terms of self-reported
general health and morbidity;
72 73 78
headaches, gastric upset,
diarrhoea, and alcohol problems;
72 73
sleep;
74
and injuries.
79–81 83
These retrospective studies were generally of low quality; all
had sample sizes ,100; and low response rates. However, one of
the larger and better-quality retrospective studies,
72 73
with a
sample of 247, a response rate .60% and adjustment for
demographic confounders, reported a significant decrease in the
age-standardised morbidity ratio amongst men from 1.02 (95%
CI 1.00 to 1.05) to 0.47 (95% CI 0.46 to 0.48), but a non-
significant decrease in women from 0.76 (95% CI 0.71 to 0.82)
to 0.67 (95% CI 0.63 to 0.71).
Fatigue
Shift work is often associated with fatigue
18 20 26
and it might be
expected that CWW, due to the longer working day, the
potential for moonlighting, or excessive overtime, might further
increase problems of fatigue amongst shift workers. However,
of the 18 intervention studies covered in this review that
measured fatigue or tiredness, in only four was there an adverse
change in fatigue levels after the introduction of CWW.
41 51 59 67
Three studies recorded improvements,
42 53 59
and in the other
eleven there was no intervention effect.
41 43–45 51 69 72 75 80 81 86
The
introduction of longer working days under CWW does not,
therefore, appear to adversely affect fatigue; however, this may
well be because of the extended rest period, which means
that the normal weekly working hours are not exceeded in a
seven-day period.
28
However, it may also be due to the
popularity of CWW interventions amongst workers (as they
increase leisure time and/or enable moonlighting)
39
, and this
may bias the findings of evaluations in a positive direction,
especially in studies with a short follow-up period.
Subsequently, it is important that employee safeguards such
as the EU Working Time Directive or other measures that limit
overtime and moonlighting are incorporated into CWW
schedules.
Work-life balance
The majority of studies that examined WLB out-
comes noted improvements after the introduction of
CWW,
34 35 37 38 40 46 48 49 53 54 62–65 68 74 77 78 82
with only a few report-
ing no intervention effect
36 39 47 50
or a worsening in WLB.
43–45 51 54
However, CWW are often popular amongst shift workers,
largely because they value the additional days off that are
afforded by the CWW model.
84
Indeed, in 22 of the CWW
studies, the intervention was either specifically requested by the
employees,
38–40 45 51 53 64 73 74 87
or implemented with their sup-
port.
48 54–59 61 65 67 71 74 78–81
Similarly, the ability of an individual
worker to adapt the new schedule to his/her needs may have
influenced findings.
Three of the five prospective cohort studies with control groups
(table 1) recorded significant improvements in self-reported WLB
amongst the intervention group compared with the control
group.
34 35 37 38
In the Barton-Cunningham study of 30 Canadian
police officers,
34 35
all four of the indicators of wellbeing used in the
study were significantly improved in the intervention group (eg
time spent on domestic chores improved in the intervention group
from a mean of 7.8 to 16.0, whereas the comparison mean
worsened from 8.6 to 6.5, F = 14.7, p,0.01). These improvements
all disappeared when the old eight-hour schedulewas restored.
34 35
Similarly, in the Totterdell and Smith study of 70 UK police
officers
37
all WLB indicators were improved in the intervention
group (for example, a reduction was recorded in the intervention
group for ‘‘insufficient time for family’’, intervention mean 56.4
to 15.5, comparison mean 63.8 to 62.6, F= 41.61, p,0.001).
However, there were significant differences between the inter-
vention and control groups at baseline, which suggests that the
findings need to be replicated in larger studies with well-matched
control groups.
Review
768 J Epidemiol Community Health 2008;62:764–777. doi:10.1136/jech.2007.067249
on 5 November 2009 jech.bmj.comDownloaded from
Table 2 Compressed Working Week: other prospective studies (grouped by study design)
Study
Design and critical appraisal
(see criteria in box 3) Setting and participants
Summary results
q= improvement Q= worsening «= little change
Prospective cohort studies
Stinson & Hazlett, 1975
40
One-month follow-up Hospital, Canada Tired on the job «
Final sample: n = 23
Critical appraisal: 1247910
Nurses, mainly female
Five eight-hour shifts, two days
off to three/four 12-hour shifts,
four/three days off
Time available for recreation
Not feeling overloaded with work
q
«
Eaton & Gottselig, 1980
41
Six-month follow-up
Final sample: n = 24
Critical appraisal: 127910
Hospital, Canada
Nurses, mainly female
Eight-hour shifts to 12-hour shifts
Personal Health Survey:
Health complaints
Cardiovascular complaints
Anxiety
Anger-frustration
Nurses perception questionnaire:
Fatigue
Felt more rested
Absence
Accidents and injuries
Minnesota Satisfaction Questionnaire:
Job satisfaction
Turnover
Incidents and errors
Q
Q
Q
Q
Q
q
«
«
«
Q
«
Peacock et al, 1983
42
Six-month follow-up Police Force, Canada Sleep duration q
Final sample: n = 75 Police officers Alertness «
Critical appraisal: 17910 Eight eight-hour shifts, four days
off to five 12-hour shifts, three
days off
Rosa et al, 1989; Lewis &
Swaim, 1986; Rosa, 1991
43–45
Seven-month follow-up
Final sample: n = 50
Critical appraisal: 15910
Processing plant, USA
Control room operators, mainly
male aged 25–34
Five/seven eight-hour shifts,
two/four days off to three/four
12-hour shifts, three/six days off
Gastrointestinal state (night)
Gastrointestinal state (day)
Exercise
Napping after shift (night)
Napping after shift (day)
Stress
Total sleep time
Number of awakenings
Sleep depth
Sleep quality
Sleep latency
Adjust personal routine for work
Missed social events
q
«
Q
q
«
«
«
«
«
«
«
Q
«
Jansen & Mull, 1990
46
Six-month follow-up
Final sample: n = 87
Critical appraisal: 127910
Confectionary Factory, Netherlands
Packaging department workers,
all female, 46 full-time, 41 part-time
Five eight-hour shifts, two days off
to three 12-hour shifts, four days off
Fatigue
Gastrointestinal complaints
Time spent with family
Satisfaction with leisure time
«
«
q
«
Slota & Balas-Stevens, 1990
47
Three-month follow-up Hospital, USA Absence q
Final sample: n = 36
Critical appraisal: 12910
Nurses, all female
Five eight-hour shifts, two days off to
three 12.5-hour shifts, four days off
Concern about scheduling of vacation time
Ability to request time off
Incidents and errors
Personal productivity
«
«
«
«
Pierce & Dunham, 1992
48
12-month follow-up
Final sample: n = 50
Critical appraisal: 1247910
Police Force, USA
Police officers, mainly male
Seven/ten eight-hour shifts, two/three
days off to four 12-hour shifts, four
days off
Physiological distress
Fatigue
Schedule interference with personal activities
Stress
Satisfaction with leisure time
Life satisfaction
Satisfaction with organisational association
Satisfaction with workload
Job satisfaction
Organisational effectiveness
Performance
q
q
q
q
q
q
«
«
q
q
«
Williams, 1992
49
Six-month follow-up
Final sample: n = 131
Critical appraisal: 124567910
Chemical Plant, USA
Operators, mainly white males
Six/seven eight-hour shifts, two/four
days off to three/four 12-hour shifts,
two to seven days off
Depression
Absence
Accidents
General life satisfaction
Conflict between work and non-work time
Social/community involvement
Planning activities with family
Job satisfaction
q
«
«
q
q
«
q
«
Continued
Review
J Epidemiol Community Health 2008;62:764–777. doi:10.1136/jech.2007.067249 769
on 5 November 2009 jech.bmj.comDownloaded from
Table 2 Continued
Study
Design and critical appraisal
(see criteria in box 3) Setting and participants
Summary results
q= improvement Q= worsening «= little change
Rosa & Bonnet, 1993
50
Eight-month follow-up
Final sample: n = 10
Critical appraisal: 17910
Gas Processing Plant, USA
Computer operators, all male
Four/seven eight-hour shifts, two/three
days off to two/three 12-hour shifts,
two/three days off
Sleepiness (day)
Sleepiness (night)
Total sleep time (night)
Total sleep time (day)
Sleep depth
Sleep latency
Number of awakenings
Exercise
Work-related adjustment of meal times
Work-related adjustment of personal schedules
q
«
q
«
Q
«
«
«
«
«
Todd et al, 1993
51
Six-month follow-up
Final sample: n = 150
Critical appraisal: 1247910
Hospital, UK
Nurses, mainly female
Three/four 12-hour shifts, three/four
days off
Dissatisfaction with fatigue
Dissatisfaction with ease of getting childcare
Dissatisfaction with amount of time spent with
family
Dissatisfaction with how personal life is put
second
Job satisfaction
Q
Q
Q
Q
Q
Williamson et al, 1994
52
Seven-month follow-up
Final sample: n = 18
Critical appraisal: 1247910
Computer Company, Australia
Computer operators (80%) and
supervisors (20%)
Two to five eight-hour shifts, one/two
days off to four 12-hour shifts, four
days off
Loss of appetite
Gastrointestinal symptoms
Sleep and fatigue
Headaches
Irritability
Heart problems
GHQ
Visit to doctor
Consumption of social drugs
Job satisfaction
q
q
q
q
q
q
q
«
«
«
Freer & Murphy-Black, 1995
53
One-month follow-up Hospital, UK Stress «
Final sample: n = 13
Critical appraisal: 14569
Nurses and midwives
12-hour flexible shifts
Enjoyment at work
Morale at work
q
q
Campolo et al, 1998
54
12-month follow-up
Final sample: n = 20
Critical appraisal: 1249
Hospital, Australia
Nurses, all female
Six-hour morning shifts, eight-hour
afternoon shifts, 9.5-hour night shifts
to four 12-hour shifts, three days off
Fatigue
Gastrointestinal symptoms
Absence
Sleep length
Sleep quality
Work demands
Time spent on hobbies
Time with family and friends
Performance
q
Q
«
«
«
Q
q
«
«
Di Milia, 1998
55
Two-, three-, four- and five-month
follow-ups
Final sample: n = 3
Critical appraisal: 15910
Coal mine, Australia
Electricians, all male
Seven eight-hour shifts, two/four days
off to four 12-hour shifts, two/eight
days off
Sleep duration «
Paley et al, 1994a; 1994b;
1998
56–58
16-month follow-up
Final sample: n = 15
Critical appraisal: 1245910
Fire Department, USA
Fire fighters, all male
Five/seven eight-hour shifts, two/three
days off to two 10-hour day shifts, two
14-hour night shifts, four days off
Sleep length (night)
Sleep length (day)
Sleepiness
q
«
«
Heslegrave et al, 2000
59
One-month follow-up
Final sample: n = 120
Critical appraisal: 127910
Metal Mine, Canada
Mining operatives, mostly male
Five eight-hour shifts, two days off
(weekends) to two/three/four 10-hour
shifts, two/three days off
Sleep duration (day)
Sleep duration (night)
Sleep duration (rest)
Tiredness (day)
Tiredness (rest)
Tiredness (night)
Gastrointestinal problems
Headaches
Performance (day)
Performance (night)
Q
«
«
Q
Q
«
q
q
Q
q
Johnson & Sharit, 2001
60
11-month and 8-year follow-ups
Final sample: n = 104
Critical appraisal: 1478910
Manufacturing Company, USA
Production workers
Eight-hour rotating shifts to 12-hour
rotating shifts
Sleep between shifts
Sleep difficulties
Health disorders
Satisfaction with system
Productivity
Production quality
q
q
q
q
q
q
Continued
Review
770 J Epidemiol Community Health 2008;62:764–777. doi:10.1136/jech.2007.067249
on 5 November 2009 jech.bmj.comDownloaded from
The Swedish study of 46 chemical plant workers
38
also saw
significant improvements in WLB with both time for social/
family activities (intervention mean 2.65 to 3.02, comparison
mean 3.25 to 3.02, p,0.05), and satisfaction with hours
(intervention mean 3.53 to 4.62, comparison mean 4.29 to
4.5, p,0.05) increasing amongst the intervention group.
There are some issues (as above) about the suitability of the non-
randomised, non-matched control group (see table 1).
The other prospective study with a control group of 45 UK
police officers
39
found no changes in WLB (workload, social
Table 2 Continued
Study
Design and critical appraisal
(see criteria in box 3) Setting and participants
Summary results
q= improvement Q= worsening «= little change
Von Borkenhagen-Chandler,
2004
61
One-month follow-up
Final sample: n = 121
Critical appraisal: 1 7 9
Aerospace Manufacturing Company, USA
Final assembly and flight test workers
Five eight-hour shifts, two days off to
four 10-hour shifts (Mon–Thurs) with
three days off or three 12-hour shifts
(Fri-Sun) with four days off
Absence
Job satisfaction
q
q*
Prospective repeat cross-section studies with control group
Duchon et al, 1994,
1997; Keran et al, 1994{
62–64
10-month follow-up
Final sample: n = 22
(17 intervention, 5 control)
Critical appraisal: 14579
Metal mine, Canada
Miners
Seven eight-hour shifts, two/three
days off to four 12-hour shifts, four
days off
Health problems
Eating habits
Sleep difficulties after night shift
Minor aches and pains
Stress
Stanford Sleepiness Scale:
Sleepiness
Sleep length
Family life
Morale
«
q
Q
Q
«
«
«
q
q
Smith et al, 1998
65
Six-month follow-up
Final sample: n = 62
(47 intervention, 15 control)
Critical appraisal: 124578910
Sewage treatment plant, Australia
Sewage workers
Seven eight-hour shifts, two/days off
to two/three 12-hour shifts, two/four
days off
GHQ-12:
Psychological complaints
Minor health complaints
Circadian malaise
Muscular complaints
Minor infections
Day sleep quality
Night sleep quality
Tiredness
Fatigue
Physical health
Mental health
Interference of work with home life
Interference of work with social life
Work-life satisfaction
Work performance
q
«
«
«
«
«
«
«
«
«
«
q
q
«
«
Cydulka et al, 1994
66
One- and six-month follow-ups
Final sample: n = 140 (27
intervention, 113 control)
Critical appraisal: 124578910
Hospital, USA
Ambulance workers and paramedics
Six eight-hour shifts, two days off to three
12 -hour shifts, two days off
Somatic distress
Organisational stress
Job dissatisfaction
«
«
«
Prospective repeat cross-section studies
Heslegrave et al, 2000
67
12-month follow-up
Final sample: n = 66
Critical appraisal: 12457910
Nuclear Power Plant, Canada
Power plant operators, mainly male
Three/four/seven nine-hour shifts, two/six
days off to four 12.5-hour shifts, four days
off
Fatigue
Sleep
Performance
Q
«
Q
Mitchell & Williamson, 2000
68
Six-month follow-up
Final sample: n = 12
Critical appraisal: 12457910
Electrical Power Station, Australia
Power station workers (supervisors, fire
fighters, turbine operators), all male
Seven eight-hour shifts, one/two/four days
off to five/six 12-hour shifts, two/three/seven
days off
Health complaints
Alcohol consumption
Sleep quality
Absence
Sleep disturbance
Sleep length
Chronic fatigue
Physical health
GHQ
Somatic anxiety
Feeling stressed
Social life
Domestic life
Coping with social life
Coping with home life
Work performance
q
q
q
Q
«
«
«
«
«
«
«
q
q
q
q
«
Effect sizes have been added to the text where appropriate and the detailed results are available in online table E2.
{Results only presented for the intervention group.
*Amongst some workers only.
Review
J Epidemiol Community Health 2008;62:764–777. doi:10.1136/jech.2007.067249 771
on 5 November 2009 jech.bmj.comDownloaded from
Table 3 Compressed Working Week – retrospective studies (grouped by study design)
Study
Design and critical appraisal
(see criteria in box 3) Setting and participants
Summary results
q= improvement Q= worsening
«= little change
Retrospective cohort studies with control group
Venne, 1993; 1997
69 70
Historical data: 12-month pre-average,
24-month post-average
Final sample: n = 102
(70 intervention, 32 control)
Critical appraisal: 457910
Prison, Canada
Prison guards
Five eight-hour shifts, two days off to two/three
12-hour shifts, two/three days off
Absence «
Yamada et al, 2001
71
Historical data: 2-, 8-, 14- and
24-month follow-ups
Final sample: n = 205
(189 intervention, 16 control)
Critical appraisal:
24569
Electronic parts manufacturer, Japan
Processing machine operators
Five eight-hour shifts, two days off to two/three
12-hour shifts, two/three days off
Lower back pain
Stiff shoulder
Joint pain
Limb pain
Dimmed sight
Sore throat
Poor sleep
Diminished alertness
Tiredness
Irritation
Head heaviness
BMI
Weight
Blood pressure
«
«
«
«
«
«
«
«
«
«
«
«
«
«
Retrospective cohort studies
Laundry & Lees, 1989;
1991
72 73
Historical data: 120-month pre-average,
120-month post-average
Final sample: n = 247
Critical appraisal: 24578910
Synthetic yarn factory, Canada
Factory workers, 85% male
Five eight-hour shifts, two days off to 12-hour
shifts
Morbidity (male)
Morbidity (female)
Headaches
Gastric upset
Diarrhoea
Alcohol problems
General malaise
Nervous conditions
Minor injury rate
Severe injury rate
Injury rate (male)
Injury rate (female)
q
«
q
q
q
q
«
«
q
«
q
«
Conrad-Beetschart, 1990
74
After only recall data: one-month post
Final sample: n = 78
Critical appraisal: 2479
Oil refinery, Switzerland
Operators, mainly male
Five eight-hour shifts, two days off to two/three
12-hour shifts, two/three days off
Sleep
Health
Leisure time
Time with partner
q
«
q
q
Pollock et al, 1994
75
Historical data: 18-month pre-average,
18-month post-average
Petrochemical manufacturer and fertiliser
manufacturer, Australia
Injury rates «
Final sample: n = 300 Manufacturing workers.
Critical appraisal: 2459 Five eight-hour shifts, two days off to four
12-hour shifts, four/six days off
Barter-Trenholm, 1997
76
After only recall data
Final sample: n = 218
Critical appraisal: 247910
Police Force, Canada
Police officers
Five eight-hour shifts, one in three weekends
off to 12-hour shifts, one in two weekends off
Sleep patterns
Tiredness
Effectiveness
«
«
«
Vega & Gilbert, 1997
77
After only recall data: eight-month
post
Historical data: 12-month pre-average,
12-month post-average
Final sample: 34
Critical appraisal: 27910
County Sheriff’s Department, USA
Patrol officers, majority male and white
Five eight-hour shifts, two days off to
three 13.3-hour shifts, four days off
Fatigue
Quality of professional lives
Quality of personal lives
Family and personal activities
Productivity
«
q
q
q
q
Richbell et al, 1998*
78
After only recall data
Historical data: 12-month pre-average,
12-month post-average
Final sample: n = 90
Critical appraisal: 2 9
Police force, UK
Police officers
Five eight-hour shifts to Ottawa system
(9/10-hour days 10-hour nights).
Health
Absence
Quality of life
Morale
Service
q
q
q
q
q
Wootten, 2000a, 2000b
79 80
Historical data: three-month
pre-average, three-month post-average
Final sample: n = 20
Critical appraisal: 2459
Hospital, UK
Nurses
7.5-hour to 12-hour shifts
Absence
Accidents
Staffing costs
Errors
Q
q
q
q
Continued
Review
772 J Epidemiol Community Health 2008;62:764–777. doi:10.1136/jech.2007.067249
on 5 November 2009 jech.bmj.comDownloaded from
domestic interference) once shift work experience had been
taken into consideration. Similarly, the study of 85 mine
workers
36
found no differences between the intervention and
control groups for family satisfaction. Importantly though,
none of the prospective cohort studies with control groups
identified a decrease in WLB after the implementation of the
CWW interventions. As noted above, these studies tended to
employ relatively short periods of follow-up and small samples,
and so, despite the controlled design, the evidence they present
is suggestive rather than convincing.
Consistently, the prospective uncontrolled studies (table 2),
including two of the studies with at least 12 months follow-up,
found that aspects of WLB improved after the introduction of
CWW interventions.
40 46 48 49 54 62–65 68
WLB indicators (such as
time available for recreation, time spent with family, or conflict
between work and non-work time) improved in eight
studies.
40 46 48 49 54 62–65 68
Some smaller and less methodologically
robust studies (e.g. low response and follow-up rates) did not
identify any changes in WLB as a result of the intervention.
47 50
Only three studies,
43–45 51 54
of which all but one
51
were revealed
by our critical appraisal process to be of questionable
methodological quality (small sample size, low response and
follow-up rates, etc), reported any decreases in WLB and in two
of these less robust studies only one or two aspects of WLB
declined whilst others improved
54
or were unaffected.
43–45
In all of the retrospective studies that measured the effects of
CWW interventions on WLB, it was found to improve.
74 77 78 82
For example, improvements were reported in leisure time and
time spent with partner,
74
quality of life
77
and family life,
78
and
child care.
82
However, the critical appraisal process suggested
that these studies had some methodological problems particu-
larly in terms of low baseline response rates,
77 78
low or no
follow-up response rates,
74 77 78 82
and little adjustment for non-
responders or confounders.
74 77 78 82
Health and work-life balance
The results of the CWW studies suggest a link between
improved WLB and improved health. Three of the prospective
studies with control groups,
34 35 37 38
six of the prospective
studies without a control group
48 49 54 62–65 68
and three of the
retrospective studies reporting increases in WLB,
74 78 82
also
reported improvements in health, particularly mental health.
Changes in WLB were less likely to be accompanied by changes
in measures of physical health. For example, in five studies,
36 43–
45 47 50
health improvements occurred despite no accompanying
changes in WLB. This tentatively suggests that whilst changes
in mental or physical health and WLB can clearly occur
separately, positive changes in WLB can translate into positive
mental health effects. The relationship between WLB and
physical health, however, is less clear. Of course, this finding
may reflect the self-reported nature of the health and WLB
outcomes. However, this link and possible causal pathway
should be examined further in future prospective studies.
Organisational outcomes
Generally, the studies suggested that the organisational effects
of the CWW were small or absent with most studies finding no
evidence of either benefit or detriment.
34–37 42 47 49 52 54 65 66 68 78
Three of the prospective cohort studies with control groups
(table 1) measured effects on performance (job satisfaction or
Table 3 Continued
Study
Design and critical appraisal
(see criteria in box 3) Setting and participants
Summary results
q= improvement Q= worsening
«= little change
Baker et al, 2000
81
Historical data: nine-month pre-average,
12- and 24-month post-averages
Final sample: not stated
Critical appraisal: 245710
Coal Mine, Australia
Miners, maintenance workers, preparation plant
workers
Eight-hour shifts to A: four 12-hour shifts,
two/six days off; then from A to B: as
system A with addition of three consecutive night
shifts and no cap on overtime
Absence
Injury incident rate
Q
q
Bloodworth et al, 2001
82
After only recall data
Historical data: two-month pre-average,
two-month post-average
Final sample: 16
Critical appraisal: 2 4
Hospital, UK
Nurses, all female
Five 7.5-hour shifts, two days off to two
6.25-hour shifts, two 12-hour shifts, three
days off
Tiredness
Absence
Child care
Performance
Staff costs
Errors and incidents
«
q
q
«
q
«
Retrospective repeat cross-section studies
Brinton, 1983
83
Historical data: five-month pre-average,
five-month post-average
Final sample: 76
Critical appraisal: 2459
Paper Mill, USA
Wood yard workers, all male
Five eight-hour shifts, two days off to four
12-hour shifts, three/four days off
Injury frequency rate
Absence
q
q
Effect sizes have been added to the text where appropriate and the detailed results are available in online table E3.
*This study also used qualitative focus groups.
Box 3 Critical appraisal criteria
30–32
1. Is the study prospective?
2. Is there a representative sample?
3. Is there an appropriate control group?
4. Is the baseline response greater than 60%?
5. Is the follow-up greater than 80% in a cohort study, or
greater than 60% in a cross-sectional study?
6. Have the authors adjusted for non-response and drop-out?
7. Are the authors’ conclusions substantiated by the data
presented?
8. Is there adjustment for confounders?
9. Were the entire intervention group exposed to the
intervention? Was there any contamination between the
intervention and control groups?
10. Were appropriate statistical tests used?
Review
J Epidemiol Community Health 2008;62:764–777. doi:10.1136/jech.2007.067249 773
on 5 November 2009 jech.bmj.comDownloaded from
effectiveness at work).
34–37
None found any significant differ-
ences between the intervention and control groups. Similarly, in
the other prospective cohort studies (table 2) the majority of the
sixteen that measured organisational outcomes found no
effect,
42 47 49 52 54 65 66 68
whilst several reported improvements; in
morale,
53 62–64
job satisfaction,
61 48 60
productivity and quality
60
or
organisational effectiveness.
48
However, four studies reported
adverse organisational effects such as an increase in turnover,
41
decreased job satisfaction
51
or decreased performance.
59 67
Amongst the five retrospective studies that had organisational
outcomes,
76–80 82
four identified benefits in terms of reduced staff
costs and errors,
79 80 82
productivity,
77
or morale.
78
Overall, the
balance of best evidence suggests that there were few positive or
negative organisational effects, though it is possible that
negative findings in this area may not have been published or
may otherwise be unavailable (for example, for reasons of
commercial confidentiality).
DISCUSSION
Overall, the evidence base on the health effects of CWW
interventions is perhaps best described as cautiously positive:
positive because whilst the CWW interventions might not
always improve the self-reported health of shift workers, they
are seldom detrimental (indeed, the five prospective cohorts
with control groups found no detrimental effects on health);
and cautious because of the methodological quality of the
current evidence base (box 4). In contrast, the evidence on the
effects of CWW interventions on the WLB of shift workers
seems more conclusive (although the comments about metho-
dological quality still apply): the CWW improves WLB.
Research implications
The evidence base on changing the organisation of shift work by
introducing the CWW is relatively large by systematic review
standards, both in terms of the intervention studies covered in
this research report (40 in total), and the wider descriptive
epidemiological literature.
29
However, there are still some large
evidence gaps, most notably in terms of any effects of shift
work interventions on inequalities in health amongst working-
age populations. The majority of studies were conducted in
fairly homogeneous populations (eg police officers, male
production workers, or female nurses) and, perhaps in part
due to this, only one study differentiated outcomes by
gender,
72 73
and none of the studies differentiated by occupa-
tional grade or socio-economic group.
A key question remains of whether changing the organisation
of shift work by introducing CWW has the potential to decrease
health inequalities amongst the working-age population. An
important consideration in this respect is the social patterning
of shift work in the UK, which tends to be concentrated
amongst workers from lower socio-economic groups (with the
notable exceptions of medical and emergency services staff).
27
This contributes to the generally poorer, more health-damaging
work environment experienced by manual compared with non-
manual workers. It is plausible that CWW interventions that
improve the health of shift workers may, therefore, on the
whole, help to reduce the gap in health between manual and
non-manual workers caused by the differences in working
conditions between the two groups. This possibility should be
explored further.
There is also little evidence on the effects of CWW on the
health behaviours of shift workers. Only four of the 40 studies
in this review examined health behaviours. Two studies
reported on the effects on exercise with one reporting an
increase,
34 35
whilst the other found no change;
50
one study
reported an increase in alcohol consumption,
68
and another
found no intervention effect on the consumption of social
Box 4 Methodological limitations
Although the 40 studies reviewed represent the best available
evidence on the health and work-life balance effects of
Compressed Working Week (CWW) interventions, they
were subject to a number of methodological and other
limitations.
cNo trials and only five prospective cohort studies with a
control group were located. The control groups were not
matched or randomised, and in at least one case there were
significant differences in health at baseline between the
intervention and control groups.
37
cWe elected to include all studies regardless of sample size.
However, it needs to be noted that a number of studies were
based on such small final sample sizes that their research
value is limited. For example, nine studies
50 52–58 68 79 80 82
had
final sample sizes of 20 or fewer, and there was one study
with only three participants.
55
Therefore, in our synthesis, we
have highlighted the larger studies.
cStudies were often conducted in homogeneous populations.
For example, three of the five controlled prospective cohorts
were conducted amongst police officers.
34 35 37 39
The
generalisablity of the results to other occupations is, therefore,
limited.
cThe number of small studies also raises the possibility that any
positive findings may be due to publication bias, in which
small studies with positive findings are more likely to be
published (or are otherwise more easily located by reviewers)
than those with negative findings. Similarly, bias may have
arisen as we were only able to locate studies in the public
domain, thus excluding the majority of commercial studies.
cThe health, work-life balance and organisational measures
were usually self-reported and they varied greatly from study
to study. Bias may, therefore, have occurred, as employees
were aware of the intervention and in some cases highly
involved in its design and implementation. There was a
dearth of well-validated questionnaires, such as the General
Health Questionnaire
37 39 52 65 68
or the Standard Shift Work
Index.
39
cThe study follow-ups were generally 12 months or less
34–55
59 62 74 76–80 82
and so it was not possible to analyse the longer
term health or work-life balance effects of the CWW
interventions, which may be particularly important in terms of
accumulated fatigue and physical health. The short follow-ups
may also account for the lack of a health effect (either positive
or negative) in the majority of the studies.
cThere was also a lack of information provided in some studies
about the background
38–40 42–45 52 55–58 65 68 72 73 75 76
to the
interventions or how they had been implemented.
34–46 48
50–53 55–59 61–68 71–73 75–79 82
In those studies that reported
background details, those in which the intervention was
instigated by employees or the motivation was employee
wellbeing,
34–37 41 47 49 50 60 62–64 66 69–71 74 79 80 82 83
tended to have
more positive health and work-life balance effects, whilst the
effects of those that were the most overtly driven by economic
motives were often negative or negligible.
46 51 53 54 59 61 67 77
Review
774 J Epidemiol Community Health 2008;62:764–777. doi:10.1136/jech.2007.067249
on 5 November 2009 jech.bmj.comDownloaded from
drugs.
52
Furthermore, there were only two studies on the
Ottawa CWW system,
37 78
and so the effects of particular CWW
systems is another area that could be examined in future
research.
In addition, the research studies reviewed were subject to a
number of methodological limitations (see box 4) such as
inadequate control groups, lack of detail about implementa-
tion, small sample sizes and short follow-ups. Perhaps most
importantly, the majority of outcomes were self-reported and
this may have led to confounding, particularly in terms of
whether employees were supportive or unsupportive of the
imposed intervention. Therefore, in the future, prospective,
well-controlled studies, which measure objective health out-
comes, and which describe the background to the study and
the implementation of the intervention, are needed.
85
Studies
that examine the mental health effects of CWW interventions
and any interaction with changes in WLB would be the most
useful.
Policy implications
The existing evidence, albeit somewhat methodologically
limited, suggests that introducing the CWW may enhance the
WLB of shift workers. There is also evidence to suggest that it is
not detrimental to self-reported health in the short term.
Importantly, CWW interventions tend to have either positive or
negligible organisational effects and so employee health and
WLB may be improved through the workplace without
damaging company productivity or competitiveness. This
message may be a useful aid in implementing the recent cross-
departmental Health and Safety Executive, Department of
Health and Department for Work and Pensions’ ‘‘Health, Work
and Wellbeing’’ strategy
86
amongst employers. Changing shift
work organisation and working practices to make them more
conducive to a WLB does not necessarily need a warning caveat
about the dangers to productivity or competitiveness.
Acknowledgements: The work in this paper was undertaken by the Centre for Public
Policy and Health (University of Durham), the MRC Public and Social Health Sciences
Unit (Glasgow), the Centre for Reviews and Dissemination (University of York), and the
Department of Public Health (University of Liverpool) as part of the work of the Public
Health Research Consortium (PHRC). The Public Health Research Consortium is funded
by the Department of Health Policy Research Programme. The views expressed in the
publication are those of the authors and not those of the DH. Information about the
wider programme of the PHRC is available from www.york.ac.uk/phrc
Funding: Department of Health Policy Research Programme (Public Health Research
Consortium).
Competing interests: None.
REFERENCES
1. Townsend P, Davidson N. The Black Report. In: Townsend P, Whitehead M,
Davidson N, eds. Inequalities in Health: The Black Report and the Health Divide.
London: Penguin, 1992.
2. Whitehead M. The Health Divide. In: Townsend P, Whitehead M,
Davidson N, eds. Inequalities in Health: the Black Report and the Health Divide.
London: Penguin, 1992.
3. Acheson D. Independent Inquiry into Inequalities in Health (the Acheson Report).
London: HMSO, 1998.
4. Waddell G, Burton A. Is work good for your health and well-being? London: HMSO,
2006.
5. Marmot M, Siegrist J, Theorell T, et al. Health and the psychosocial environment at
work. In: Marmot M, Wilkinson R, eds. The social determinants of health. New York:
Oxford University Press, 1999.
6. Beatson M. Labour market flexibility. London: Department of Employment, 1995.
7. Rajaratnam S, Arendt J. Health in a 24-h society. Lancet 2001;358:999–1005.
8. United States Department of Health and Human Services, National Institute for
Occupational Safety and Health. The Changing Organization of Work and the Safety
and Health of Working People: Knowledge Gaps and Research Directions. National
Occupational Research Agenda Report. HHS (NIOSH) Publication No. 2002–116,
2002.
9. Leka S, Griffiths A, Cox T. Work organization and stress. World Health Organization
Protecting Workers’ Health Series No. 3. Nottingham, UK: Institute of Work, Health
and Organizations, 2003.
10. Wanless D. Securing good health for the whole population: final report [The Wanless
Report], London: HM Treasury, 2004.
11. Department of Health.Choosing Health: Making healthy choices easier. London:
HMSO, 2004.
12. Marmot M, Smith G, Stansfeld S, et al. Health inequalities among British civil
servants – the Whitehall II study. Lancet 1991;337:1387–93.
13. Kuper H, Marmot M. Job strain, job demands, decision latitude, and risk of coronary
heart disease within the Whitehall II study, J Epidemiol Commun H 2003;57:147–53.
Policy implications
cThe evidence suggests that introducing the Compressed
Working Week may enhance work-life balance for shift
workers. It does not appear to be detrimental to self-reported
health in the short term.
cImportantly, Compressed Working Week interventions tend to
have either positive or negligible organisational effects and so
health and wellbeing may be improved through the workplace
without damaging productivity or competitiveness.
cThe Compressed Working Week could, therefore, be an
important tool for both policymakers and employers in terms
of promoting healthier work places and improving working
practices.
What is already known on this subject
cA large number of observational studies suggest that shift
work negatively effects employee health and work-life
balance.
cShift work is common: one in five European workers are
involved in some form of shift work.
cShift work is socially patterned – less common amongst
graduates and more common amongst manual workers.
cOne hypothesis is that organisational level interventions such
as the Compressed Working Week may be effective in
reducing these negative health effects and perhaps also
impact upon social inequalities in health and work-life balance.
What this study adds
cThis is the first study to systematically review 40 intervention
studies of the effects on the health and work-life balance of
shift workers of Compressed Working Week interventions.
cThe methodologically limited evidence base suggests that the
Compressed Working Week appears to improve the work-life
balance of shift workers, and that it appears to do so with little
or no adverse health or organisational effects.
cIt is unclear what the effects are on health inequalities,
although as shift work is concentrated amongst lower
occupational groups it is plausible that effective Compressed
Working Week interventions could help reduce the health gap
between manual and non-manual workers.
Review
J Epidemiol Community Health 2008;62:764–777. doi:10.1136/jech.2007.067249 775
on 5 November 2009 jech.bmj.comDownloaded from
14. Bosma H, Marmot M, Hemingway H, et al. Low job control and risk of
coronary heart disease in Whitehall II (prospective cohort) study, Brit Med J
1997;314:558–65.
15. North F, Syme S, Feeney A, et al. Psychosocial work environment and sickness
absence among British civil servants: The Whitehall II Study. Am J Publ Health
1996;86:332–40.
16. Karasek R. Stress prevention through work reorganization: a summary of 19 case
studies, Conditions of Work Digest 1992;11:23–42.
17. Akerstadt T. Psychological and psychophysiological effects of shift work.
Scand J Work Environ Health 1990;16:67–73.
18. Monk T, Folkard S. Making shift work tolerable. London: Taylor and Francis, 1992.
19. Pilcher J, Lambert B, Huffcutt A. Differential effects of permanent and
rotating shifts on self-report sleep length: a meta-analytic review. Sleep
2000;23:155–63.
20. European Foundation.BEST European Studies on time: Shift work and health.
European Foundation: Dublin, 2000.
21. Bøggild H. Shift work and heart disease: Epidemiological and risk factor aspects.
PhD Thesis. Centre for Working Time Research, Aalborg Regional Hospital, Aalbory.
2000.
22. Institute for Environment and Health.Shift Work and Breast Cancer: Report of an
Expert Meeting 12 November 2004 (Web Report W23), Leicester, UK, MRC Institute
for Environment and Health, 2005. Available from http://www.silsoe.cranfield.ac.uk/
ieh/pdf/w23.pdf#search (accessed 20 Sep 2005).
23. Swerdlow A. Shift work and breast cancer: a critical review of the epidemiological
literature. Health and Safety Executive Research Report 132, London: HSE, 2003.
24. Mozurkewich E, Luke B, Avni M, et al. Working conditions and adverse pregnancy
outcome: a meta-analysis. Obstetrics and Gynecology 2000;95:623–35.
25. Harrington J. Health effects of shift work and extended hours of work. Occup
Environ Med 2001;58:68–72.
26. Health and Safety Executive.Shift work and fatigue. 2006. Available from http://
www.hse.gov.uk/humanfactors/shiftwork/index.htm (accessed 19 Sep 2005).
27. McOrmond T. Changes in working trends over the past decade. Labour Market
Trends 2004;112:1–11.
28. Ronen S, Primps S. The Compressed Working Week as organisational change:
Behavioral and attitudinal outcomes. Academy of Management Review 1981;6:61–
74.
29. Smith L, Folkard S, Tucker P, et al. Work shift duration: a review comparing eight
hour and 12 hour shift systems. Occup Environ Med 1998;55:217–29.
30. Deeks J, Dinnes J, D’Amico R, et al. Evaluating non-randomised intervention studies.
Health Technology Assessment 2003:7–27.
31. Egan M, Bambra C, Thomas S, et al. The psychosocial and health effects of
workplace reorganisation 1: a systematic review of interventions that aim to increase
employee participation or control. J Epidemiol Commun H. In press.
32. Bambra C, Egan M, Thomas S, et al. The psychosocial and health effects of
workplace reorganisation 2: A systematic review of task restructuring interventions. J
Epidemiol Commun H. In press.
33. Centre for Reviews and Dissemination.Undertaking Systematic Reviews of
Research on Effectiveness: CRD’s Guidance for Carrying Out or Commissioning
Reviews (2nd Edn), Report 4, York: CRD, 2001.
34. Barton-Cunningham J. Exploring the impact of a ten-hour compressed shift
schedule. Journal of Occupational Behaviour 1981;2:217–22.
35. Barton-Cunningham J. Compressed shift schedules: altering the relationship
between work and non-work. Public Administration Review 1982;Sept/Oct:438–46.
36. Barton-Cunningham J. A compressed shift schedule: Dealing with some of the
problems of shift work. Journal of Organisational Behaviour 1989;10:213–45.
37. Totterdell P, Smith L. Ten hour days and eight hour nights: can the Ottawa shift
system reduce the problems of shift work? Work & Stress 1992;6:139–52.
38. Lowden A, Kecklund G, Axelsson J, et al. Change from an 8 hour shift to a 12 hour
shift, attitudes, sleep, sleepiness and performance. Scan J Work Environ Health
1998;24(Suppl 3):69–75.
39. Smith l, Hammond T, Macdonald I, et al. 12-h shifts are popular but are they a
solution? Int J Ind Ergonomics 1998;21:323–31.
40. Stinson S, Hazlett C. Nurse and physician opinion of a modified work week trial.
J Nursing Admin 1975;Sept:21–6.
41. Eaton P, Gottselig S. Effects of longer hours, shorter week for intensive care nurses.
Dimensions in Health Service 1980;Aug:25–7.
42. Peacock B, Glube R, Miller M, et al. Police officers’ responses to 8 and 12 hour shift
schedules. Ergonomics 1983;26:479–93.
43. Rosa R, Colligan M, Lewis P. Extended work days: effects of 8 hour and 12 hour
rotating shift schedules on performance, subjective alertness, sleep patterns, and
psychosocial variables. Work & Stress 1989;3:21–32.
44. Lewis P, Swaim D. Evaluation of a 12 hour/day shift schedule. Proceedings of the
Human Factors Society 30th Annual Meeting 1986:885–89.
45. Rosa R. Performance, alertness, and sleep after 3.5 years of 12 h shifts: a follow up
study. Work & Stress 1991;5:107–16.
46. Jansen B, Mul C. The time compensation module system as an alternative for the
compressed working week. In: Costa G, Cessana G, Kogi K, et al., eds. Shiftwork:
health, sleep and performance. Frankfurt: Peter Lang, 1990.
47. Slota M, Balas-Stevens S. Implementing and evaluating a change to 12 hour shifts.
Neonatal Network 1990;8:51–56.
48. Pierce J, Dunham R. The 12 hour work day: A 48 hour, eight-day week. The
Academy of Management Journal 1992;35:1086–98.
49. Williams B. Implementing 12 hour rotating shifts: the effect on employee attitudes.
MA Thesis. University of Houston-Clear Lake, USA, 1992.
50. Rosa R, Bonnet M. Performance and alertness on 8 h and 12 h rotating shifts at a
natural gas utility. Ergonomics 1993;36:1177–93.
51. Todd C, Robinson G, Reid N. 12 hour shifts: job satisfaction of nurses. J Nursing
Management 1993;1:215–20.
52. Williamson A, Gower C, Clarke B. Changing the hours of shift work: a control of 5
and 12 hour shift rosters in a group of computer operators. Ergonomics 1994;
37:287–98.
53. Freer Y, Murphy-Black T. Evaluating the effects of twelve hour shifts
against eight hour shifts on a neonatal intensive care unit. J Neonatal Nursing 1995,
July:5–9.
54. Campolo M, Pugh J, Thompson L, et al. Pioneering the 12 hour shift n Australia –
implementation and limitations. Australian Critical Care 1998;11:112–15.
55. Di Milia L. A longitudinal study of the compressed workweek: Comparing sleep on a
weekly rotating 12 h system to a faster rotating 12 h system. Int J Ind Ergonomics
1998;21:199–207.
56. Paley M, Herbert L, Tepas D. Long term evaluation of a compressed, rapidly rotating
work schedule. Proceedings of the Human Factors and Ergonomics Society 38th
Annual Meeting 1994:749–53.
57. Paley D, Tepas D. Fatigue and the shift workers: Firefighters working on a rotating
shift schedules. Human Factors 1994;36:269–84.
58. Paley M, Price J, Tepas D. The impact of a change in rotating shift schedules: A
control of the effects of 8, 10, and 14 h work shifts. Int J Ind Ergonomics
1998;21:293–305.
59. Heselgrave R, Reinish L, Beyers J, et al. The differential impact of extended 10 hour
shifts on day and night shifts. In: Hornberger S, Knauth P, Costa G, et al., eds.
Shiftwork in the 21st Century. Frankfurt: Peter Lang, 2000.
60. Johnson M, Sharit J. Impact of a change from an 8-h o a 12-h shift schedule on
workers and occupational injury rates. Int J Ind Ergonomics 2001;27:303–19.
61. Von Borkenhagen-Chandler H. Utilising job characteristics to predict job
satisfaction on alternative workweeks. PhD Thesis. Wichita State University, USA,
2004.
62. Duchon J, Kerna C, Smith T. Extended workdays in an underground mine: a work
performance analysis. Human Factors 1994;36:258–68.
63. Duchon J, Smith T, Keran C, et al. Psychophysiological manifestations of
performance during work on extended workshifts. Int J Ind Ergonomics 1997;20:39–
49.
64. Keran C, Duchon J, Smith T. Older workers and longer work days: are they
compatible? Int J Ind Ergonomics 1994;13:113–23.
65. Smith P, Wright B, Mackey R, et al. Change from slowly rotating 8 hour shifts to
rapidly rotating 8 hour and 12 hour shifts using participative shift roster design.
Scand J Work Environ Health 1998;24(Suppl 3):55–61.
66. Cydulka R, Emerman C, Shade B, et al. Stress levels in EMS personnel: A
longitudinal study with work schedule modification. Academic Emergency Medicine
1994;1:240–46.
67. Heslegave R, Rhodes W, Gil V. A prospective study examining the changes to
worker health and safety after shifting from 9 to 12.5 hour shifts. In: Hornberger S,
Knauth P, Costa G, et al, eds. Shiftwork in the 21st Century. Frankfurt: Peter Lang,
2000.
68. Mitchell R, Wiliamson A. Evaluation of an 8 hour versus a 12 hour shift roster on
employees at a power station. Applied Ergonomics 2000;31:83–93.
69. Venne R. Alternative worktime arrangements: the compressed working week. PhD
Thesis. Univeristy of Toronto, Canada, 1993.
70. Venne R. The impact of the compressed workweek on absenteeism: the case of
Ontario prison guards on a twelve hour shift. Relat Ind 1997;52:382–400.
71. Yamada Y, Kameda M, Noborisaka Y, et al. Excessive fatigue and weight gain
among clean room workers after changing from an 8 hour to a 12 hour shift.
Scand J Work Environ Health 2001;27:318–26.
72. Laundry B, Lees R. Industrial accident experience of one company on 8 and 12 hour
shift systems. J Occup Med 1991;33:903–07.
73. Lees R, Laundry B. Control of reported workplace morbidity in 8 hour and 12 hour
shifts in one plant. J Soc Occup Med 1989;39:81–84.
74. Conrad-Beetschart H. Designing new shift schedules: Participation as a critical
factor for an improvement. In: Costa G, Cessana G, Kogi K, et al., eds. Shiftwork:
health, sleep and performance. Frankfurt: Peter Lang, 1990.
75. Pollock C, Crsoo R, Taylor P. Influences of 12 versus 8 hour shiftwork on injury
patterns. Ergonomie et Lieux de Travail 1994;5:19–21.
76. Barter Trenholm S. The satisfaction of police officers and their spouses with 12 hour
shift work schedules. MSc Thesis. Memorial University of New Foundland, Canada,
1997.
77. Vega A, Gilbert M. Longer days, shorter weeks: Compressed working weeks in
policing. Public Personnel Management 2001, 1997, 26:391–402.
78. Richbell S, Simpson M, Sykes G, et al. policing with the Ottawa shift system: a
British experience. Policing: An International Journal of Police Strategies and
Management 1998;21:384–96.
79. Wootten N. Implementing 12 hour shifts on a cardiology nursing development unit.
Br J Nursing 2000;9:2095–99.
80. Wootten N. Evaluation of 12 hour shifts on a cardiology nursing development unit.
Br J Nursing 2000;9:2169–74.
81. Baker A, Heiler K, Ferguson S. The effects of a roster schedule change from 8 to 12
hour shifts on health and safety in a mining operation. J Human Ergol 2001;30:65–70.
Review
776 J Epidemiol Community Health 2008;62:764–777. doi:10.1136/jech.2007.067249
on 5 November 2009 jech.bmj.comDownloaded from
82. Bloodworth C, Lea A, Lane S, et al. Challenging the myth of the 12-hour shift: a pilot
evaluation. Nursing Standard 2001;15:33–36.
83. Brinton R. Effectiveness of the twelve hour shift. Personnel Journal 1983, May:
393–98.
84. Smith L, Hammond T, Macdonald I, et al. 12-h shifts are popular but are they a
solution? Int J Ind Ergonomics 1998;21:323–31.
85. Rychetnik L, Frommer M, Hawe P, et al. Criteria for evaluating evidence on public
health interventions, J Epidemiol Commun H 2002;56:119–27.
86. Department for Work and Pensions.Health, Work and Wellbeing –
Caring for our future. London: HMSO, 2005 Available from http://www.
dwp.gov.uk/publications/dwp/2005/health_and_wellbeing.pdf (accessed 21 Sep
2006).
Drug and Therapeutics Bulletin (DTB)
Your key source of unbiased, independent advice
For over 45 years DTB has been an independent, indispensable part of evidence-based clinical practice.
DTB offers healthcare professionals detailed assessment of, and practical advice on, individual
medicines and other treatments, groups of treatment and the overall management of disease.
DTB is now also available online at http://dtb.bmj.com:
cbrowse or search all DTB content from the latest issue back to 1994
cemail alerting, sophisticated searching, RSS feeds and full text links from cited references
cinteractive services such as My Folders for quick access to articles that you have viewed previously
and My Searches to save and re-use useful searches
ccomment online on any DTB article
To subscribe, or for further information, please visit http://dtb.bmj.com
Review
J Epidemiol Community Health 2008;62:764–777. doi:10.1136/jech.2007.067249 777
on 5 November 2009 jech.bmj.comDownloaded from
... This includes health, safety, and work environment (HSE) consequences of various work arrangements (for example, night work and long working hours), spanning biological disruption to physiological processes, impairment of physical health and psychological wellbeing, and disruption of social and domestic life (Smith et al., 1998a). Numerous literature reviews exist that address outcomes like health (Bambra et al., 2008a(Bambra et al., , 2008bHarrington, 1994;Smith et al., 1998b), sick leave (Merkus et al., 2012), safety (Parkes, 2012;Wagstaff and Sigstad Lie, 2011) and work-family balance (Bambra et al., 2008a). ...
... This includes health, safety, and work environment (HSE) consequences of various work arrangements (for example, night work and long working hours), spanning biological disruption to physiological processes, impairment of physical health and psychological wellbeing, and disruption of social and domestic life (Smith et al., 1998a). Numerous literature reviews exist that address outcomes like health (Bambra et al., 2008a(Bambra et al., , 2008bHarrington, 1994;Smith et al., 1998b), sick leave (Merkus et al., 2012), safety (Parkes, 2012;Wagstaff and Sigstad Lie, 2011) and work-family balance (Bambra et al., 2008a). ...
... Although numerous studies have addressed the consequences of different working arrangements, these studies typically include night work. Extended schedules have been studied for shorter periods, such as four days of 10-and 12-h shifts (Bambra et al., 2008a), but not for longer periods such as 12-14 days. However, studies from the Norwegian petroleum industry, pointing to 3-4 days of recovery after 14 days offshore for day shift workers (Merkus et al., 2015), represent a relevant comparison for the workers who travel far in our study, who are away from their families and have access to facilities like cantinas for any meal while working. ...
Article
With a scarcity of research on multiple working arrangements, the aim of the paper is to contribute empirical data from a Norwegian engineering, procurement, and construction enterprise that shed light on the challenges and benefits of a 14–21 working arrangement in itself and in relation to other working arrangements. We combine a sociotechnical system perspective with systematic content analysis using QSR NVivo, which reveals organizational complexity comprised of indirect, direct, positive, negative, and mutual interplays between various aspects of the enterprise, including processes and outcomes. We find that the 14–21 working arrangement, in combination with other factors of the work system, sets the premises for work processes and outcome factors that are both beneficial and challenging to individuals and the organization. We also find that work process factors, such as work and information flow as well as follow-up and facilitation, depend on the presence of, and dynamic coordination and communication among, individuals across the organization. This in turn requires a support network, work groups, and supervisors to be on the same working arrangement.
... Die gesundheitlichen Auswirkungen werden u. a. auf die chronische zirkadiane Disruption und die damit verbundenen Veränderungen in der Melatoninsynthese zurückgeführt [9,10]. Zusätzlich bedeutet eine Tätigkeit in Schichtarbeit eine Herausforderung für die Vereinbarkeit von Beruf und Privatleben [11,12]. ...
... Die [11]. Auch in einer finnischen Industrie-Kohorte zeigte sich eine höhere Mitarbeiterzufriedenheit im 12-h-Schichtsystem im Vergleich zu 8-h-Schichten [19]. ...
Article
Full-text available
Zusammenfassung Mit dem Ziel, für die Polizistinnen und Polizisten im Wechselschichtdienst (WSD) eine Reduktion potenzieller gesundheitlicher Belastungen zu ermöglichen und eine Verbesserung der Vereinbarkeit von Beruf und Privatleben zu erreichen, wurde in der Polizei Hamburg eine neue Dienstzeitregelung (DZR) entwickelt. Das neue Schichtsystem umfasst im Vergleich zur bestehenden DZR 14 statt vier 12-Stunden-Schichten in 8 Wochen, gleichzeitig aber auch 14 anstelle von 2 freien Tagen. Die neue DZR wurde in einer einjährigen Pilotphase in 6 Polizeikommissariaten (PKs) erprobt, die zuvor bei einer Abstimmung einen Zwei-Drittel-Mehrheitsbeschluss für die Teilnahme erzielten. Die Vergleichsgruppe bestand aus 17 nichtpilotierenden PKs. Für eine Prä-post-Analyse wurden vor Beginn der Pilotierung in einem umfassenden Fragebogen neben anderen Parametern die Erwartungen in Bezug auf die Umsetzung im Alltag, die Vereinbarkeit mit dem Privatleben und die Gesundheit erfasst. Nach einem Jahr wurden die Einschätzungen zu den entsprechenden Aspekten erhoben. Vor Beginn der Pilotphase (T0) nahmen 1151 (72,7 %) von insgesamt 1583 im WSD Beschäftigten an der Befragung teil, nach einem Jahr (T1) 74,3 % (1122 von 1511). In beiden Gruppen wurden zu beiden Zeitpunkten die freien Tage und bessere Regenerationsmöglichkeiten als führende Gründe für die Befürwortung der neuen DZR angegeben. Zu T0 erwarteten 16,5 % aus den pilotierenden PKs eine einfache Anpassung des privaten Alltags an die neue DZR, in T1 gaben 36,9 % an, dass diese Anpassung in der einjährigen Pilotphase leicht umzusetzen war. Eine positive Auswirkung auf die allgemeine Gesundheit berichteten 22,1 % der Frauen und 32,7 % der Männer nach der Pilotphase. Die Erwartung an eine verbesserte Regeneration stand zu Beginn der Pilotierung deutlich im Fokus der Beschäftigten. In den 6 pilotierenden PKs wurde die veränderte Schichtplangestaltung mehrheitlich positiv bewertet.
... In terms of General Strain Theory, mothers' parental goals are therefore more difficult to achieve, unless a more egalitarian parental ideology is used by both partners (Agnew et al. 2002) Second, there is a socio-economic gradient in terms of work-life balance (Kossek et al. 2015). While there are few studies that focus on the explicit relationship between socio-economic status and work-life balance, work environments that are associated with less balance are related to lower income groups (Bambra et al. 2008). Moreover, these economic sectors often use more employerfocused flexibility such as shift work, rather than employee-focused flexibility that could benefit single parents (Van Gasse and Mortelmans 2017). ...
Article
Full-text available
This study aims to define the perspectives taken by single mothers when combining work and motherhood in a stressful work-life constellation. One of the challenges for single mothers after divorce is to find a work-life balance in their single-parent family system. Regarding work-life balance, we take a General Strain Perspective, describing the work-life conflict as a combination of financial strain and role strain. We argue that both strains are the most problematic for single mothers in comparison to their married and/or male counterparts, as both finances and parenthood ideologies are more under pressure. For this reason, we explore how single mothers coped with this strain, answering the question: 'Which perspectives on the combination motherhood and work do single mothers take in their attempt to balance role strain and financial strain after divorce?' To answer this research question, we used a qualitative approach, based on 202 in-depth interviews with single mothers in Belgium. These interviews involved two groups: A primary research population of 13 single mothers and an elaborative research population of 189 single mothers. Timelines were used to structure the single mothers' narratives. The analysis resulted in the contruction of a typology of four different perspectives based on how single mothers dealt with maternal role strain and financial strain: the re-invented motherhood perspective, the work-family symbiosis perspective, the work-centered motherhood perspective and the work-family conflicted perspective. We found that perspective of single mothers in their work-life strain can be described by the flexibility and/or strictness in either their motherhood ideology and/or their work context. These results point at the needs for policymakers, employers, and practitioners to focus on initiatives improving the work-life balance of single mothers by reducing financial and role strains.
... These workers are performing regular (4 days) and backward rotations (night-evening-morning), and these can be some of the causes of the obtained values for EDS. It was shown that this type of rotation can impact sleep and fatigue in shift workers (Bambra, Whitehead, Sowden, Akers, & Petticrew, 2008;Kecklund & Axelsson, 2016). ...
Article
Excessive daytime sleepiness (EDS) is a common feature among shift workers as well as in obstructive sleep apnea (OSA) patients. There are several important accidents related to sleep disturbances causing EDS. The aim of this study was to evaluate EDS in a group of shift workers (regular rotating) from civil aviation and to compare them with OSA patients (n = 300) and with a group of regular workers (RW) (n = 140). Our sample was composed of 730 working‐age individuals (aged 18–67 years). The regular rotating shift workers (SW) sample was composed of 290 aeronautical mechanics. EDS was evaluated with the Epworth Sleepiness Scale (ESS) and defined as a score ≥ 11. The prevalence value obtained for the EDS of RW was 37.1%, for SW it was 60.7% and for OSA patients it was 40.7%. A logistic regression model for EDS in a subsample composed of men and matched for age and BMI, controlling for self‐reported sleep duration, showed an increased risk of EDS for SW (OR = 3.91, p = .001), with the RW group as reference. OSA patients did not differ from RW on EDS levels. This study emphasizes the presence of EDS in a shift work group of civil aviation professionals, which exceeded the EDS level of a positive control group of OSA patients. Sleep hygiene education for companies' workers and management is important and mitigation strategies should be implemented to reduce excessive sleepiness among workers.
Article
Full-text available
Purpose This article serves as an introduction to six articles featured in a special issue on diversity in the work–life interface. This collection of papers contains research that contemplates the work–life interface in different geographic and cultural contexts, that explores the work–life experiences of minority, marginalized and/or underresearched groups of workers and that takes into account diverse arrangements made to fulfill both work and nonwork responsibilities. Design/methodology/approach This introductory article first summarizes some of the emerging research in this area, introduces the papers in this special issue and links them to these themes and ends with highlighting the importance of using an intersectional lens in future investigations of the work–life interface. Findings These six articles provide empirically based insights, as well as new theoretical considerations for studying the interface between paid work and personal life roles. Compelling new research directions are identified. Originality/value Introducing the new articles in this special issue and reviewing recent research in this area brings together the work–life interface scholarship and diversity management studies and points to the necessity for future investigations to take an intersectional and contextualized approach to their subject matter. Keywords: Diversity, Gender, Intersectionality, Immigrants, Work-Family, Work-Life
Preprint
Full-text available
In modern society, work stress is highly prevalent. Problematically, work stress can cause disease. To help understand the causal relationship between work stress and disease, we present a computational model of this relationship. That is, drawing from allostatic load theory, we captured the link between work stress and disease in a set of mathematical formulas. With simulation studies, we then examined our model's ability to reproduce key findings from previous empirical research. Specifically, results from Study 1 suggested that our model could accurately reproduce established findings on daily fluctuations in cortisol levels (both on the group level and the individual level). Results from Study 2 suggested that our model could accurately reproduce established findings on the relationship between work stress and cardiovascular disease. Finally, results from Study 3 yielded new predictions about the relationship between workweek configurations (i.e., how working hours are distributed over days) and the subsequent development of disease. Together, our studies suggest a new, computational approach to studying the causal link between work stress and disease. We suggest that this approach is fruitful, as it aids the development of falsifiable theory, and as it opens up new ways of generating predictions about why and when work stress is (un)healthy.
Article
Surveys have revealed that teachers in England work far longer hours than their international counterparts, causing serious concern amongst both policymakers and the profession. Despite this, surprisingly little is known about the structure of and changes to teachers’ working hours. We address this gap in the evidence base by analysing four different datasets. Working hours remain high: a quarter of teachers work more than 60 hours per week during term time, 40% report that they usually work in the evening and around 10% during the weekend. However, contrary to current narratives, we do not find evidence that average working hours have increased. Indeed, we find no notable change in total hours worked over the last twenty years, no notable change in the incidence of work during evenings and weekends over a fifteen year period and no notable change in time spent on specific tasks over the last five years. The results suggests that policy initiatives have so far failed to reduce teachers’ working hours and that more radical action may need to be taken in order to fix this problem.
Article
Full-text available
Zusammenfassung Dieser Beitrag untersucht, inwieweit der Zusammenhang zwischen Merkmalen der Arbeitszeitgestaltung und psychischer Gesundheit über zeit- und belastungsbasierte Konflikte zwischen Berufs- und Privatleben (Work-Family Conflicts) mediiert wird. Als Arbeitszeitmerkmale werden Arbeitsstunden, Überstunden, Schichtarbeit, Sonn- und Feiertagsarbeit, Flexible Arbeitszeiten, Tele‑/Heimarbeit und Kommunikation außerhalb der Arbeitszeit analysiert, sowie zusätzlich die Betriebskultur in Form wahrgenommener Arbeitgebererwartungen an die Arbeitszeitgestaltung von Beschäftigten bzgl. Erreichbarkeit und Mehrarbeit. Auf Basis eines längsschnittlichen Untersuchungsdesigns und einer für deutsche Großbetriebe repräsentativen Stichprobe von Beschäftigten (N = 3965) werden Mediationsanalysen in Strukturgleichungsmodellen durchgeführt. Die Ergebnisse zeigen, dass negative Gesundheitseffekte von Schichtarbeit, Sonn- und Feiertagsarbeit, Überstunden sowie Arbeitgebererwartungen an Erreichbarkeit und Mehrarbeit teilweise oder sogar vollständig über solche Konflikte vermittelt werden. Praktische Relevanz: Die Resultate zeigen, dass ein Teil des Gesundheitsrisikos dadurch erklärt wird, dass Beschäftigte auf Grund der Belastung durch eine bestimmte Arbeitszeitgestaltung größere Konflikte in der Kombination beruflicher und privater Anforderungen erleben, was sich wiederum negativ auf die psychische Gesundheit auswirkt. Dies ist von praktischer Relevanz, da die Vermeidung solcher Konflikte ein greifbarer Ansatzpunkt für betriebliche Gesundheitsförderung ist, durch Arbeitszeitgestaltung bedingte negative Konsequenzen für die Gesundheit von Beschäftigten zu vermeiden.
Chapter
Full-text available
The construction sector plays a significant role in the economy through the provision of constructed space for productive activities. The process of executing projects in the construction sector is labor intensive and often workers need to work for long hours. Evidence found in literature shows that family conflict, emotional exhaustion and job dissatisfaction are prevalent in the construction sector. These problems have negative impact on organization and project performance. Previous studies have shown that the adoption work-life balance practices lead to significant improvements in organizational performance. The purpose of this investigation is to assess the level of adoption of work-life balance practices among construction firms in Swaziland. Questionnaire survey approach was utilized in the current study. It was revealed that a large majority of the respondents are aware of work-life balance practices. Also, leave (causal, parental [paternity/maternity], and study) and wellness programs are the most commonly used work-life practices. However, work from home and part-time work are the least used. The findings of this study shed more light on the current work-balance practices in the construction sector of Swaziland. Further research is required to understand the link between work-life balance and job satisfaction.
Article
Full-text available
Study objective: Despite an overall decline in mortality rates, the social gradient in mortality has increased over the past two decades. However, evidence on trends in morbidity and cardiovascular risk factors indicates that socioeconomic differences are static or narrowing. The objective of this study was to investigate morbidity and cardiovascular risk factor trends in white collar British civil servants. Design: Self rated health, longstanding illness, minor psychiatric morbidity (General Health Questionnaire (GHQ) 30 score, GHQ caseness and GHQ depression subscale), cholesterol, diastolic and systolic blood pressure, body mass index, alcohol over the recommended limits, and smoking were collected at baseline screening (1985-88) and twice during follow up (mean length of follow up 5.3 and 11.1 years). Employment grade gradients in these measures at each phase were compared. Setting: Whitehall II, prospective cohort study. Participants: White collar women and men aged 35-55, employed in 20 departments at baseline screening. Analyses included 6770 participants who responded to all three phases. Results: Steep employment grade gradients were observed for most measures at second follow up. In general, there was little evidence that employment grade gradients have increased over the 11.1 years of follow up, but marked increases in the gradient were observed for GHQ score (p<0.001) and depression (p=0.05) in both sexes and for cholesterol in men (p=0.01). Conclusions: There is little evidence of an increase in inequality for most measures of morbidity and cardiovascular risk factors in white collar civil servants over the 11.1 years to 1998. Inequalities have increased significantly for minor psychiatric morbidity in both sexes and for cholesterol in men.
Article
The Whitehall study of British civil servants begun in 1967, showed a steep inverse association between social class, as assessed by grade of employment, and mortality from a wide range of diseases. Between 1985 and 1988 we investigated the degree and causes of the social gradient in morbidity in a new cohort of 10 314 civil servants (6900 men, 3414 women) aged 35-55 (the Whitehall 11 study). Participants were asked to answer a self-administered questionnaire and attend a screening examination. In the 20 years separating the two studies there has been no diminution in social class difference in morbidity: we found an inverse association between employment grade and prevalence of angina, electrocardiogram evidence of ischaemia, and symptoms of chronic bronchitis. Self-perceived health status and symptoms were worse in subjects in lower status jobs. There were clear employment-grade differences in health-risk behaviours including smoking, diet, and exercise, in economic circumstances, in possible effects of early-life environment as reflected by height, in social circumstances at work (eg, monotonous work characterised by low control and low satisfaction), and in social supports. Healthy behaviours should be encouraged across the whole of society; more attention should be paid to the social environments, job design, and the consequences of income inequality.
A current trend in alternative work schedules is to increase the length of the workday while decreasing the number of days in the work week. These “compressed” work schedules are popular amongst shiftworkers, in part because of longer periods of non-work days. The current research is an attempt to add to the short list of long-term evaluations of compressed work schedules. A change in work schedules from an 8 hour rotating shift schedule to a rotating 10 hour day/14 hour night operating schedule in a fire department was studied. Multiple measures were used to address a variety of outcomes associated with the new schedule. From the significant increase in satisfaction with their work schedule, it is clear that the new shift schedule is well liked by the fire fighters. Reasons for the satisfaction include significant changes in usual sleep length, a decrease in being tired or sleepy at work and an increase in free time benefits. Other results are discussed in the paper. In conclusion, the use of a compressed work schedule is beneficial when workers are allowed to sleep on the job, however, generalizations to other workplaces must be limited. Use of these popular work schedules should be limited to applications which incorporate a systematic evaluation of the new work schedule.
Article
The study consists of absenteeism measures for a group of prison guards who switched from an 8-hour work day to a 12-hour day compressed workweek (CWW) schedule with absenteeism measures for one year prior to the onset of the schedule and two years on the new schedule. Absenteeism data were compared between the CWW group and a comparison group of regular schedule guards and between the pre-CWW and CWW periods. Absenteeism levels were higher for the CWW group compared to the comparison group, and were higher over the CWW period when compared to the pre-CWW period. In the best specified models, those guards on the CWW had higher absenteeism than the comparison group, though the latter difference was not statistically significant.