Collegian (2008) 15, 43—44

avai lab le at www.sc iencedi rec t .com

EDITORIAL

Shift-work: Nursing’s sometimes silent partner

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In mid-December 2007 the International Agency for Risk onCancer (IARC) published in Lancet Oncology (the results oftheir recent evaluation of shift-work as a cancer risk inwhich ‘‘shift-work involving circadian disruption’’ was cat-egorised a Group 2A cancer risk (probably carcinogenic tohumans) Straif et al., 2007). Also in this category are agentssuch as ultra-violet light and inorganic lead compounds, mix-tures such as the emissions from high temperature frying anddiesel engine exhaust and the occupational exposure of hair-dressers or barbers. This categorisation, however, cannotbut help move shift-work related issues from the organisa-tional to a much more personal level for the many nursesconsistently working ‘‘shift-work involving circadian disrup-tion’’. But what is the basis of this decision and what isa ‘‘reasonable’’ level of concern for nurses whose workinvolves ‘‘night duty’’?

In general, shift-work is part of the life of all cliniciansand frequently accepted by those who do it as somethingthat must be tolerated, but about which very little can bedone. There is of course some level of self-selection — thosewho can’t tolerate the effects of shift-work either leavenursing or work their way to areas that minimise the amountof shift-work they do. Interestingly, although there has beenmuch shift-work research ‘‘using’’ nurses as subjects, veryfew of these studies have been initiated by nurses or attemptto address questions of direct interest to nurses. In the main,shift-work studies have found nurses a convenient groupfor gender comparison when exploring questions originat-ing from other industries or when exploring gender-basedinterests in the effects of shift-work. Consequently, until rel-atively recently shift-work has been nursing’s rather silentpartner, However, recent initiatives in areas such as driversafety within the transport industry (and debates about whois legally and thus financially responsible) and the increas-ing emphasis on the management of the risk associated withclinical decision making in health are starting to raise organ-isational interest in shift-work.

In most formal definitions shift-work is considered to bework conducted outside of normal business hours — in short,work commencing before 8 am and finishing before 6 pm. Inrecent years increasing flexibility in work hours and associ-

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ted arrangements has made this once very simple definitionncreasingly complex in its application, but essentially thedea remains the same. If you start work early or finishate you are now commonly considered to be a shift-worker.ndustries that maintain a 24-h schedule of work — includingarge parts of the health and service sectors, the hospitalityndustry, manufacturing and mining industries — are com-only understood to be shift-working industries, and it is

hese groups that the recent IARC announcement directlyffects, as circadian disruption involves moving the timef sleep from the 11 p.m.—7 a.m. cycle that is accepted ashe norm in most developed societies and generally involvesleeping during daytime hours. Thus, the determination that‘shift-work involving circadian disruption’’ is a probableancer risk is only of direct relevance to those who workhift-work that involves night work. Although the next obvi-us questions may well ask what type of night work, howuch, what hours, on what schedule, in the absence of

ny specific dose-response data in relation to the amountf shift-work (dose) that may ‘‘cause’’ cancer (response)Pukkala & Harma, 2007), it may be useful to delve into theebate surrounding this categorisation before becoming toooncerned about one’s personal shift schedule.

The IARC is a medically based organisation whose role its to evaluate the various cancer risks that are frequentlydentified by the broad spectrum of research available inny particular area. The work of the IARC has without doubteen influential in decreasing exposure to many potentialarcinogens, however the location of the IARC within a med-cal context and its reliance on particular forms of analysisan be critiqued (Stewart, 2008) as influencing the group’serspective in some areas. Not perhaps surprisingly there isnother perspective on this debate, originating from thoseho research shift-work from perspectives that do not share

he construction of shiftwork as a potential cause of disease.Since first reported in 2001 (Hansen, 2006), an increased

isk of breast cancer associated with occupational shift-

ork exposure has been ridentified in several studies

Schernhammer et al., 2001; Schernhammer, Kroenke,aden, & Hankinson, 2006; Megdal, Kroenke, Laden,ukkala, & Schernhammer, 2005; Davis & Mirick, 2006).

ernational Books Australia Pty Ltd) on behalf of Royal College of Nursing, Australia.

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chernhammer et al. (2001) report the findings of analy-es of data obtained through the Nurses Health Study — arospective cohort study that commenced in 1989 and col-ected data in 2001 on the basis of self-report questionnaires

as follows: ‘‘the risk of breast cancer was found to be mod-stly elevated in women who worked for 20 or more years onotating night shifts compared with those who never workedotating night shifts’’ (p. 110).

Not unreasonably further epidemiological work was thenndertaken, some of which substantiated the link and oth-rs that challenged it (Schwartzbaum, Ahiborn, & Feychting,007) from statistical and study design perspectives but andlso on the lack of a common or clearly defined understand-ng of what shift-work, night work and associated circadianisruption were held to be within these studies. Of equaloncern is the support of an as yet experimental hypothesisStevens, 1987) that links levels of melatonin (a light sensi-ive hormone secreted at night) with protection from cancer.his supports the argument that work at night in well-

it environments suppresses melatonin secretion and thusncreases the risk of cancer. This position has been clearlyrticulated in a recent editorial published in the Scandi-avian Journal of Work Environment & Health (Pukkala &arma, 2007), which concludes with a call for additionalata on all aspects of this debate.

The multiple views and clearly limited availability of dataust substantiate the concerns of those who are aware

f the multiple forms of shift-work and the vast differ-nces in the work undertaken by those working night shifts.or example, many night nurses tend to work in darkenedlinical environments to promote the sleep of patients, aircumstance commonly compared, without examination tohe work circumstances of those working on a well-lit man-facturing line.

While the real level of risk and the basis for the recentARC decision are as yet difficult to determine in detail (fullrguments are published in monographs usually not availablentil 18 months after the initial Policy Watch announcementn the Lancet), the reported efforts of several shift-work

esearchers to move this listing from ‘‘shift-work’’ to ‘‘shiftork involving circadian disruption’’ are appreciated. While

t is not necessarily time to become overly alarmed abouthe potentially carcinogenic effects of ‘‘shift-work involv-ng circadian disruption’’, it may well be time for nursing

Editorial

o become much more alert to the information providedhrough the research of shift-work in general and theotential impact of such findings on the organisation of nurs-ng work. It is certainly past time for us to be changingpproaches to shift-work on the basis of what may seemo be ‘‘a good idea’’ — 12-h shifts for example — but that isnother shift-work story!

eferences

avis, S., & Mirick, D. (2006). Circadian disruption, shift work andthe risk of cancer: A summary of the evidence and studies inSeattle. Cancer Causes Control, 17, 539—545.

ansen, J. (2006). Risk of breast cancer after night- and shift work:Current evidence and ongoing studies in Denmark. Cancer CausesControl, 17, 531—537.

egdal, S., Kroenke, C., Laden, F., Pukkala, E., & Schernhammer, E.(2005). Night work and breast cancer risk: A systematic reviewand meta-analysis. European Journal of Cancer, 41, 2023—2032.

ukkala, E., & Harma, M. (2007). Does shift work cause cancer?Scandinavian Journal of Work Environment & Health, 33(5),321—323.

chernhammer, E., Kroenke, C., Laden, F., & Hankinson, S. (2006).Night work and risk of breast cancer. Epidemiology, 17(1),108—111.

chernhammer, E., Laden, F., speizer, F., Willet, W., Hunter, D.,Kawachi, I., et al. (2001). Rotating night shifts and risk of breastcancer in woman participating in the nurses’ health study. Jour-nal of the National Cancer Institute, 93, 1563—1568.

chwartzbaum, J., Ahiborn, A., & Feychting, M. (2007). Cohortstudy of cancer risk among male and female shift workers.Scandinavian Journal of Work Environment & Health, 33(5),336—349.

tevens, R. G. (1987). Electric power use and breast cancer. Amer-ican Journal of Epidemiology, 125, 556—561.

tewart, B. (2008). Banding carcinogenic risks in developed coun-tries: A procedural basis for qualitative assessment. MutationResearch, 658, 124—151.

traif, K., Baan, R., Grosse, Y., Secretan, G., El Ghissassi, F., Bou-vard, V., et al. (2007). Carcinogenicity of shift-work, paintingand fire-fighting. The Lancet — Oncology, 8, 1065—1066.

Sandra West, RN, PhD, FRCNAUniversity of Sydney, Faculty of Nursing and Midwifery,

Sydney, NSW 2006, AustraliaE-mail address: s.west@usyd.edu.au