BACKGROUND: Previous studies of the risk of heart disease after shift work reached different estimates and review authors disagree about the validity of some of the studies. A cross sectional study showed that shift workers had a higher prevalence of nearly every unfavourable work environment factor investigated. Conflicts at work and low decision latitude were more frequent among shift workers, and all-day walking or standing work and part-time jobs were more often found among female shift workers. OBJECTIVES: To estimate the risk of circulatory disease in a prospective follow up of a representative sample of gainfully employed Danes, considering known or suspected confounding factors. METHODS: A cohort of 5517 people who were gainfully employed in 1990 were followed up for all hospital treatments due to circulatory diseases (390-458, ICD-8; I00-I99, ICD-10) from 1991 to 2002 inclusive. A log linear Poisson regression model was applied to control confounding factors and calculate the relative risk for 927 men and women working nights, evenings, or other non-day shifts compared to 4579 day workers. RESULTS: Non-day workers compared to day workers had a relative risk (RR) for all circulatory diseases of 1.31 (95% CI 1.06-1.63). Without control for BMI and smoking, the RR estimate was 1.33 (95% CI 1.07-1.65). For a subgroup of workers with at least three years' seniority, the RR was 1.40 (95% CI 1.09-1.81). The population based aetiological fraction of shift work was estimated to 5%. CONCLUSION: This study adds to a growing body of evidence suggesting that shift work carries an excess risk of circulatory diseases.
OBJECTIVE: To investigate if job insecurity and poor labour market chances predict a decline in self-rated health in the Danish workforce. DESIGN: Job insecurity, labour market chances, self-rated health and numerous covariates were measured in 1809 women and 1918 men who responded to a questionnaire in 1995 and again in 2000. Multivariate logistic regression analyses were used to analyse the impact of job insecurity and labour market chances measured in 1995 on decline in health in 2000. SETTING: Prospective cohort study with a representative sample of the Danish workforce using the Danish Work Environment Cohort Study (DWECS). All participants were employed at baseline. MAIN RESULTS: Women with job insecurity had an increased risk of a decline in health at follow-up, after adjustment for all covariates (OR = 1.78, 95% CI: 1.24 to 2.54). Effect estimates were strongest among women 50 years of age or younger with poor labour market chances (OR = 2.13, 95% CI: 1.32 to 3.45). Among men, there was no main effect for job insecurity. However, men aged 50 years or younger with poor labour market chances showed an OR of 1.64 (95% CI: 0.95 to 2.84) for a decline in health. CONCLUSION: Job insecurity is a predictor for a decline in health in employed women in Denmark. Among men, a suggestive effect of job insecurity was found in employees aged 50 years or younger with poor labour market chances.
BACKGROUND: One in seven married couples is involuntarily infertile. Several chemical exposures in the work environment have been hypothesized to affect female reproduction, and some are present in products used in hairdressing and related trades. Recent Swedish findings indicate that employment in hairdressing poses a risk for female reproductive function. This study examined the possible association between work as a hairdresser and subsequent hospital contact due to female infertility. METHODS: A cohort of all women in Denmark aged 20-44 years on 1 January 1998 (baseline) and registered as economically active hairdressers, according to national registers, was formed to calculate age-standardized risk ratios (RRs) for hospital contacts due to female infertility during a 5-year follow-up period. Hairdressers were compared to a standard population, that is, all economically active women in Denmark aged 20-44 years at baseline, and to women working as shop assistants. RESULTS: Sixty-eight cases of hospital contact due to female infertility were observed among the female hairdressers. On the basis of the standard population, the expected number was 73.27, which gives an observed RR of 0.928 (95% CI: 0.72-1.18). Hairdressers and shop assistants exhibited similar rates of hospital contact due to female infertility (1.01; 95% CI: 0.77-1.29). CONCLUSION: The findings are not corroborating the hypothesis that hairdressers are at increased risk of infertility, but small risks in the entire group or high risks in small subgroups may not be detected by the study.