Database

The review finds evidence for an increased incidence of breast cancer among women who work the night shift for several decades. There is no reason to conclude that the association is causal. Evidence from: Health Council of the Netherlands Report No. 2006/15E, June 29, 2006 “Night work and breast cancer: a causal relationship?” In the Committee’s opinion, the research findings do not, at present, justify recommending special measures for women who perform night work for prolonged periods in addition to the current breast cancer screening programme. If new, scientifically sound research findings were to produce evidence of a causal relationship then one could consider what specific measures need to be taken. Further detail: 6#5-6 30

The study finds evidence of a weak link between shift work and increased risk of circulatory disease. Evidence from: F Tuchsen et al. Occ. Env. Med. (2006) Vol.63 p 451 – 455 “A 12 year prospective study of circulatory disease among Danish shift workers” The risk of incident circulatory disease was related to shift work even after all other variables had been corrected for. RR = 1.3 (95% CI = 1.1 to 1.6). The attributable fraction of circulatory disease in the whole population was estimated to be 5% (i.e. nationally, among workers, 5% of circulatory disease was attributable to shift working). Further detail: 6#5-6 29

The study finds evidence in support of an association between rotating shift work and death due to ischaemic heart disease. There was no association with cerebrovascular disease. Evidence from: Y Fujino et al. Am. J. Epidemiol. (2006) Vol. 164 p 128 – 135 “A Prospective Cohort Study of Shift Work and Risk of Ischemic Heart Disease in Japanese Male Workers” Compared with the day workers, the rotating-shift workers had a significantly higher risk of death due to ischemic heart disease (RR = 2.32, 95% (CI) = 1.37, 3.95) whereas fixed-night work was not associated with ischemic heart disease (RR = 1.23, 95% CI = 0.49, 3.10). Further detail: 6#5-6 28

A study of self reported fatigue among nurses’ aides in Norway. Shift work was one of the variables assessed but the main focus was on psychosocial influences. Shift work was not identified as a significant predictor of persistent fatigue. Evidence from: W Eriksen. Occ. Env. Med. (2006) Vol.63 p 428 – 434 “Work factors as predictors of persistent fatigue: a prospective study of nurses’ aides” Supervisors can help manage fatigue by varying work demands. Help with managing persistent health problems, encouraging physical fitness and cessation of smoking would seem to be legitimate roles for the employer and had the strongest predictive power in this research. Further detail: 6#5-6 27

There are no absolute measures to predict fatigue. The fatigue index allows planners to compare the likely effect on fatigue of different shift work regimes. Evidence from: HSE RR 446 “The development of a fatigue / risk index for shift workers” Further detail: 6#5-6 26

The study adds weight to the view that exposure to environmental tobacco smoke could be associated with an increased risk of early, spontaneous abortion. Evidence from: L George et al. Epidemiology (2006) Vol.17 p 500 – 505 “Environmental Tobacco Smoke and Risk of Spontaneous Abortion” Abortion is an indivisible outcome. The relative risk of spontaneous abortion was increased for women exposed to ETS; OR = 1.7 (95% CI = 1.2 to 2.4) and for women who smoked; OR = 2.1 (95% CI = 1.4 to 3.3). Further detail: 6#5-6 25