Ann Dyreborg Larsen

A Review of the Effect of the Psychosocial Working Environment on Physiological Changes in Blood and Urine

The aim of the present survey was to provide a literary review of current knowledge of the possible association between the psychosocial working environment and relevant physiological parameters measured in blood and urine. Literature databases (PubMed, Toxline, Biosis and Embase) were screened using the key words job, work-related and stress in combination with selected physiological parameters. In total, 51 work place studies investigated the associations between the psychosocial working environment and physiological changes, of which 20 were longitudinal studies and 12 population-based studies. The studied exposures in work place/population-based studies included: job demands (26/8 studies), job control (24/10 studies), social support and/or leadership behaviour (12/3 studies), effort-reward imbalance (three/one studies), occupational changes (four studies), shift work (eight studies), traumatic events (one study) and other (five studies). The physiological responses were catecholamines (adrenaline, noradrenaline) (14 studies), cortisol (28 studies), cholesterol (23 studies), glycated haemoglobinA(1c) (six studies), testosterone (nine studies), oestrogens (three studies), dehydroepiandrosterone (six studies), prolactin (14 studies), melatonin (one study), thyroxin (one study), immunoglobulin (Ig) A (five studies), IgG (four studies), IgM (one study) and fibrinogen (eight studies). In general, fibrinogen and catabolic indicators, defined as energy releasing, were increased, whereas the anabolic indicators defined as constructive building up energy resources were decreased when the psychosocial working environment was perceived as poor. In conclusion, in this review the association between an adverse psychosocial working environment and HbA(1c), testosterone and fibrinogen in serum was found to be a robust and potential candidate for a physiological effect of the psychosocial working environment. Further, urinary catecholamines appear to reflect the effects of shift work and monotonous work.

Risk of Cryptorchidism among Sons of Horticultural Workers and Farmers in Denmark

OBJECTIVES Previous studies indicate an increased risk of cryptorchidism, incomplete testicular descent, among sons of women working with pesticides. This study assessed the risk of cryptorchidism among boys of parents employed as horticultural workers and farmers using nationwide registers on occupation and cryptorchidism. METHODS The cohort consisted of >600 000 boys born in Denmark from 1980-2007 with a parent in employment during pregnancy. These boys were followed for cryptorchidism from 1980-2009 comparing risks among sons of horticultural workers and farmers with sons of parents in other occupations. Hazard ratios (HR) and 95% confidence intervals (95% CI) were estimated using Cox regression adjusting for parental age, birth years, parity, and geographical region. RESULTS Sons of maternal farmers were at increased risk of cryptorchidism (157 cases; HR 1.31, 95% CI 1.12-1.53) compared to boys of mothers in other occupations (15 511 cases). Paternal occupation as farmer was unrelated to the risk among sons. Maternal occupation as a horticultural worker was associated with a non-significantly increased risk (72 cases; HR 1.20, 95% CI 0.95-1.52). A similar association was found for paternal horticultural workers. Sons of maternal farmers or horticultural workers who likely worked in the first trimester were not at increased risk of cryptorchidism. CONCLUSIONS This nationwide cohort study found a slightly increased risk of cryptorchidism in sons of maternal horticultural workers and farmers. However, subgroup analyses indicated similar findings for paternal horticultural workers, and no association for women likely working in the first trimester. The main findings should therefore be interpreted with caution.

How do different definitions of night shift affect the exposure assessment of night work

ABSTRACT The aim is to show how different definitions affect the proportion of shifts classified as night shifts. The Danish Working Hour Database was used to calculate number of night shifts according to eight definitions. More than 98% of the total night shifts were night shifts by use of both the reference definition (at least 3 h of work between 24:00 and 05:00) and definitions using a period during the night. The overlap with definitions based on starting and ending time was less pronounced (64–71 %). The proportion of classified night shifts differs little when night shifts are based on definitions including a period during the night. Studies based on other definitions may be less comparable.

Workshop on ethics and communication in Copenhagen 11–13.3.2007

Workshop on ethics and communication in Copenhagen 11–13.3.2007 The European Environment and Health Strategy adopted by the European Commission in 2003 presented a new vision on how to address environment and health in an integrated way by putting health in the centre of environmental policy. Based upon the Strategy the Commission adopted in 2004 a Communication on the Environment and Health Action Plan 2004 – 2010. In Action 3 of this Action Plan the European Commission announced to develop a coherent approach to Human Biomonitoring in Europe in close cooperation with the Member States.

Working Time Arrangements as Potential Risk Factors for Ischemic Heart Disease Among Workers in Denmark: A Study Protocol

Background It has long been suspected that a worker’s risk of developing an ischemic heart disease (IHD) may be influenced by his or her working time arrangements. A multitude of studies have been performed, and special attention has been given to long working hours and nighttime work. The statistical powers of the individual studies have, however, generally been too low to either dismiss or confirm an actual relationship, and meta-analyses of underpowered studies are generally associated with publication bias. Hence, uncertainty remains and whether these factors indeed are related to IHD has yet to be settled. Objective This project will test whether the incidences of IHD and usage of antihypertensive drugs among employees in Denmark are independent of weekly working hours and nighttime work. The objective of this paper is to present the intended analyses. Methods We will link individual participant data from the Danish labor force survey, 1999–2013, to data on socioeconomic status, industry, emigrations, redeemed prescriptions, hospitalizations, and deaths from registers covering the entire population of Denmark. The study will include approximately 160,000 participants, who will be followed through the registers, from the time of the interview until the end of 2014, for first occurrence of IHD and for antihypertensive drug treatment. We will use Poisson regression to analyze incidence rates as a function of nighttime work and of weekly working hours. Results We expect results to be ready in mid-2017. Conclusions To our knowledge, this will be the largest study ever of its kind. It will, moreover, be free from hindsight bias, since the hypotheses, inclusion criteria, significance levels, and statistical models will be completely defined and published before we are allowed to link the exposure data to the outcome data.

Long working hours and stroke among employees in the general workforce of Denmark

Aims: A systematic review and meta-analysis have found that long working hours were prospectively associated with an increased risk of overall stroke. The primary aim of the present study was to test if this finding could be reproduced in a sample that has been randomly selected from the general workforce of Denmark. A secondary aim was to estimate the association for haemorrhagic and ischaemic stroke separately. Methods: Individual participant data on 20- to 64-year-old employees were drawn from the Danish Labour Force Survey, 1999–2013, and linked to data on socio-economic status (SES), migrations, hospitalisations and deaths from national registers. The participants were followed from the time of the interview until the end of 2014. Poisson regression was used to estimate age-, sex- and SES-adjusted rate ratios for stroke as a function of weekly working hours. Results: With 35–40 working hours per week as reference, the estimated rate ratios for overall stroke were 0.97 (95% confidence interval (CI) 0.83–1.13) for 41–48 working hours, 1.10 (95% CI 0.86–1.39) for 49–54 working hours and 0.89 (95% CI 0.69–1.16) for ≥55 working hours. The estimated rate ratios per one category increase in working hours were 0.99 (95% CI 0.93–1.06) for overall stroke, 0.96 (95% CI 0.88–1.05) for ischaemic stroke and 1.15 (95% CI 1.02–1.31) for haemorrhagic stroke. Conclusions: Our analysis does not support the hypothesis that long working hours are associated with increased rates of overall stroke. It suggests, however, that long working hours might be associated with increased rates of haemorrhagic stroke.

Night work, long work weeks, and risk of accidental injuries. A register-based study

Objectives The aims of this study were to (i) investigate the association between night work or long work weeks and the risk of accidental injuries and (ii) test if the association is affected by age, sex or socioeconomic status. Methods The study population was drawn from the Danish version of the European Labour Force Survey from 1999-2013. The current study was based on 150 438 participants (53% men and 47% women). Data on accidental injuries were obtained at individual level from national health registers. We included all 20-59-year-old employees working ≥32 hours a week at the time of the interview. We used Poisson regression to estimate the relative rates (RR) of accidental injuries as a function of night work or long work weeks (>40 hours per week) adjusted for year of interview, sex, age, socioeconomic status (SES), industry, and weekly working hours or night work. Age, sex and SES were included as two-way interactions. Results We observed 23 495 cases of accidental injuries based on 273 700 person years at risk. Exposure to night work was statistically significantly associated with accidental injuries (RR 1.11, 99% CI 1.06-1.17) compared to participants with no recent night work. No associations were found between long work weeks (>40 hours) and accidental injuries. Conclusion We found a modest increased risk of accidental injuries when reporting night work. No associations between long work weeks and risk of accidental injuries were observed. Age, sex and SES showed no trends when included as two-way interactions.

Payroll data based description of working hours in the Danish regions

ABSTRACT The aim was to describe the organization of working hours in the Danish regions according to sex, age and calendar year. Based on the Danish Working Hour Database (DWHD), individuals were classified according to schedules: Permanent day (57.8%), evening (1.7%), or night (1.2%); day/evening (22.0%); day/night (6.6%); evening/night (0.6%); and day/evening/night (10.2%). More men (9.1%) than women (5.9%) worked day/night, whereas more women (10.9%) than men (7.4%) worked day/evening/night. More young than older employees worked day/evening/night, and fewer worked permanent day or night. From 2008 to 2015 we observed a trend towards more employees working permanent day and fewer employees working other schedules. Altogether DWHD provides a strong tool in research on working hours.

Long weekly working hours and ischaemic heart disease: a follow-up study among 145 861 randomly selected workers in Denmark

Objectives The aim of the present study was to test if incidences of ischaemic heart disease (IHD) and usage of antihypertensive drugs are independent of weekly working hours (WWH) among full-time employees in Denmark. Design and participants Data on WWH from participants of the Danish labour force surveys, 1999–2013, were linked on an individual level to national registers with data on socioeconomic status (SES), industry, emigrations, redeemed prescriptions, hospital contacts and deaths. Participants were followed until the end of 2014 (on average 7.7 years). Poisson regression was used to model incidence rates as a function of WWH. The analyses were controlled for calendar time, time passed since start of follow-up, employment in the healthcare industry, age, sex, SES and night work. Results In total, we found 3635 cases of IHD and 20 648 cases of antihypertensive drug usage. The rate ratio of IHD was 0.95 (95% CI 0.85 to 1.06) for 41–48 compared with 32–40 WWH and 1.07 (0.94 to 1.21) for >48 compared with 32–40 WWH. The corresponding rate ratios for antihypertensive drug usage were 0.99 (0.95 to 1.04) and 1.02 (0.97 to 1.08). No statistically significant interactions between WWH and sex, SES and night work, respectively, were found. Conclusion In this Danish sample, we did not find any statistically significant association between WWH and IHD or antihypertensive drug usage.

Joint association of sleep problems and psychosocial working conditions with registered long-term sickness absence. A Danish cohort study

OBJECTIVES Sleep problems and adverse psychosocial working conditions are associated with increased risk of long-term sickness absence. Because sleep problems affect role functioning they may also exacerbate any effects of psychosocial working conditions and vice versa. We examined whether sleep problems and psychosocial working conditions interact in their associations with long-term sickness absence. METHODS We linked questionnaire data from participants to two surveys of random samples of the Danish working population (N=10 752) with registries on long-term sick leave during five years after questionnaire response. We defined sleep problems by self-reported symptoms and/or register data on hypnotics purchases of hypnotics. Psychosocial working conditions included quantitative and emotional demands, influence, supervisor recognition and social support, leadership quality, and social support from colleagues. Using time-to-event models, we calculated hazard ratios (HR) and differences and examined interaction as departure from multiplicativity and additivity. RESULTS During 40 165 person-years of follow-up, we identified 2313 episodes of long-terms sickness absence. Sleep problems predicted risk of long-term sickness absence [HR 1.54, 95% confidence interval (95% CI) 1.38-1.73]. This association was statistically significantly stronger among participants with high quantitative demands and weaker among those with high supervisor recognition (P<0.0001). CONCLUSIONS High quantitative demands exacerbated the association of sleep problems with risk of long-term sickness absence whereas high supervisor recognition buffered this association. To prevent long-term sickness absence among employees with sleep problems, workplace modifications focusing on quantitative demands and supervisor recognition may be considered. Workplace interventions for these factors may more effectively prevent sickness absence when targeted at this group. The efficacy and effectiveness of such interventions needs to be established in future studies.