Association of rotating shift work schedules and the use of prescribed sleep medication: A prospective cohort study.

We examined whether working rotating shifts, with or without night work, is associated with the purchase of prescribed sleep medication, and whether the association is dependent on age. Data were obtained from a longitudinal cohort study of Finnish public sector employees who responded to questions on work schedule and background characteristics in 2000, 2004 and 2008. The data were linked to national register data on redeemed prescriptions of hypnotic and sedative medications, with up to 11 years of follow-up. Age stratified Cox proportional hazard regression models were computed to examine incident use of medication comparing two groups of rotating shift workers (those working shifts that included night shifts and those whose schedules did not include night shifts) with day workers who worked in a similar range of occupations. Shift work with night shifts was associated with increased use of sleep medication in all age groups, after adjustments for sex, occupational status, marital status, alcohol consumption, smoking and physical activity levels (hazard ratio [HR], [95% confidence interval, CI] 1.14 [1.01-1.28] for age group ≤39 years; 1.33 [1.19-1.48] for age group 40-49 years; 1.28 [1.13-1.44] for age group ≥50 years). Shift work without nights was associated with medication use in the two older age groups (HR [95% CI] 1.14 [1.01-1.29] and 1.17 [1.05-1.31] for age groups 40-49 years and >50 years, respectively). These findings suggest that circadian disruption and older age puts rotating shift workers, and especially those who work nights, at increased risk of developing clinically significant levels of sleep problems.

Associations between shift work and use of prescribed medications for the treatment of hypertension, diabetes, and dyslipidemia: a prospective cohort study.

Objective This study examined the associations between shift work and use of antihypertensive, lipid-lowering, and antidiabetic medications. Methods Survey data from two cohorts of Finnish men (N=11 998) and women (N=49 944) working in multiple occupations where shift work was used were linked to national Drug Prescription Register data, with up to 11 years of follow-up. In each cohort, age-stratified Cox proportional hazard regression models were computed to examine any incident use of prescription medication for each of the three medical conditions, separately comparing each of two groups of rotating shift workers (those whose schedules included night shifts, and those whose schedules did not include night shifts) with day workers who worked in a similar range of occupations. Results In the larger cohort, among participants aged 40-49 at baseline, shift work without night shifts was associated with increased use of type-2 diabetes medication after adjustments for sex, occupational status, marital status, alcohol consumption, smoking, and physical activity [hazard ratio (HR) 1.28, 95% confidence interval (CI) 1.01-1.62], while shift work with night shifts was associated with increased use of dyslipidemia medication after adjustments (HR 1.33, 95% CI 1.12-1.57). There were no such associations among younger and older shift workers. Also in the larger cohort, among those aged <50 years at baseline, both types of shift work were associated with increased use of hypertension medication after adjustments [up to HR 1.20 (95% CI 1.05-1.37)]. There were no positive associations in the smaller cohort. Conclusions There was mixed evidence regarding the use of medications for cardiovascular risk factors by shift workers. Selection effects may have affected the associations.

Socioeconomic differences in healthy and disease-free life expectancy between ages 50 and 75: a multi-cohort study.

BACKGROUND: There are striking socioeconomic differences in life expectancy, but less is known about inequalities in healthy life expectancy and disease-free life expectancy. We estimated socioeconomic differences in health expectancies in four studies in England, Finland, France and Sweden. METHODS: We estimated socioeconomic differences in health expectancies using data drawn from repeated waves of the four cohorts for two indicators: (i) self-rated health and (ii) chronic diseases (cardiovascular, cancer, respiratory and diabetes). Socioeconomic position was measured by occupational position. Multistate life table models were used to estimate healthy and chronic disease-free life expectancy from ages 50 to 75. RESULTS: In all cohorts, we found inequalities in healthy life expectancy according to socioeconomic position. In England, both women and men in the higher positions could expect 82-83% of their life between ages 50 and 75 to be in good health compared to 68% for those in lower positions. The figures were 75% compared to 47-50% for Finland; 85-87% compared to 77-79% for France and 80-83% compared to 72-75% for Sweden. Those in higher occupational positions could expect more years in good health (2.1-6.8 years) and without chronic diseases (0.5-2.3 years) from ages 50 to 75. CONCLUSION: There are inequalities in healthy life expectancy between ages 50 and 75 according to occupational position. These results suggest that reducing socioeconomic inequalities would make an important contribution to extending healthy life expectancy and disease-free life expectancy.

Lifestyle factors and risk of sickness absence from work: a multicohort study.

BACKGROUND: Lifestyle factors influence the risk of morbidity and mortality, but the extent to which they are associated with employees' absence from work due to illness is unclear. We examined the relative contributions of smoking, alcohol consumption, high body-mass index, and low physical activity to diagnosis-specific sickness absence. METHODS: We did a multicohort study with individual-level data of participants of four cohorts from the UK, France, and Finland. Participants' responses to a lifestyle survey were linked to records of sickness absence episodes, typically lasting longer than 9 days; for each diagnostic category, the outcome was the total number of sickness absence days per year. We estimated the associations between lifestyle factors and sickness absence by calculating rate ratios for the number of sickness absence days per year and combining cohort-specific estimates with meta-analysis. The criteria for assessing the evidence included the strength of association, consistency across cohorts, robustness to adjustments and multiple testing, and impact assessment by use of population attributable fractions (PAF), with both internal lifestyle factor prevalence estimates and those obtained from European populations (PAFexternal). FINDINGS: For 74 296 participants, during 446 478 person-years at risk, the most common diagnoses for sickness absence were musculoskeletal diseases (70·9 days per 10 person-years), depressive disorders (26·5 days per 10 person-years), and external causes (such as injuries and poisonings; 12·8 days per 10 person-years). Being overweight (rate ratio [adjusted for age, sex, socioeconomic status, and chronic disease at baseline] 1·30, 95% CI 1·21-1·40; PAFexternal 8·9%) and low physical activity (1·23, 1·14-1·34; 7·8%) were associated with absences due to musculoskeletal diseases; heavy episodic drinking (1·90, 1·41-2·56; 15·2%), smoking (1·70, 1·42-2·03; 11·8%), low physical activity (1·67, 1·42-1·96; 19·8%), and obesity (1·38, 1·11-1·71; 5·6%) were associated with absences due to depressive disorders; heavy episodic drinking (1·64, 1·33-2·03; 11·3%), obesity (1·48, 1·27-1·72; 6·6%), smoking (1·35, 1·20-1·53; 6·3%), and being overweight (1·20, 1·08-1·33; 6·2%) were associated with absences due to external causes; obesity (1·82, 1·40-2·36; 11·0%) and smoking (1·60, 1·30-1·98; 10·3%) were associated with absences due to circulatory diseases; low physical activity (1·37, 1·25-1·49; 12·0%) and smoking (1·27, 1·16-1·40; 4·9%) were associated with absences due to respiratory diseases; and obesity (1·67, 1·34-2·07; 9·7%) was associated with absences due to digestive diseases. INTERPRETATION: Lifestyle factors are associated with sickness absence due to several diseases, but observational data cannot determine the nature of these associations. Future studies should investigate the cost-effectiveness of lifestyle interventions aimed at reducing sickness absence and the use of information on lifestyle for identifying groups at risk. FUNDING: NordForsk, British Medical Research Council, Academy of Finland, Helsinki Institute of Life Sciences, and Economic and Social Research Council.

Sickness absence diagnoses among abstainers, low-risk drinkers and at-risk drinkers: consideration of the U-shaped association between alcohol use and sickness absence in four cohort studies.

AIMS: To estimate differences in the strength and shape of associations between alcohol use and diagnosis-specific sickness absence. DESIGN: A multi-cohort study. Participants (n = 47 520) responded to a survey on alcohol use at two time-points, and were linked to records of sickness absence. Diagnosis-specific sickness absence was followed for 4-7 years from the latter survey. SETTING AND PARTICIPANTS: From Finland, we had population cohort survey data from 1998 and 2003 and employee cohort survey data from 2000-02 and 2004. From France and the United Kingdom, we had employee cohort survey data from 1993 and 1997, and 1985-88 and 1991-94, respectively. MEASUREMENTS: We used standard questionnaires to assess alcohol intake categorized into 0, 1-11 and > 11 units per week in women and 0, 1-34 and > 34 units per week in men. We identified groups with stable and changing alcohol use over time. We linked participants to records from sickness absence registers. Diagnoses of sickness absence were coded according to the International Classification of Diseases. Estimates were adjusted for sex, age, socio-economic status, smoking and body mass index. FINDINGS: Women who reported drinking 1-11 units and men who reported drinking 1-34 units of alcohol per week in both surveys were the reference group. Compared with them, women and men who reported no alcohol use in either survey had a higher risk of sickness absence due to mental disorders [rate ratio = 1.51, 95% confidence interval (CI) = 1.22-1.88], musculoskeletal disorders (1.22, 95% CI = 1.06-1.41), diseases of the digestive system (1.35, 95% CI = 1.02-1.77) and diseases of the respiratory system (1.49, 95% CI = 1.29-1.72). Women who reported alcohol consumption of > 11 weekly units and men who reported alcohol consumption of > 34 units per week in both surveys were at increased risk of absence due to injury or poisoning (1.44, 95% CI = 1.13-1.83). CONCLUSIONS: In Finland, France and the United Kingdom, people who report not drinking any alcohol on two occasions several years apart appear to have a higher prevalence of sickness absence from work with chronic somatic and mental illness diagnoses than those drinking below a risk threshold of 11 units per week for women and 34 units per week for men. Persistent at-risk drinking in Finland, France and the United Kingdom appears to be related to increased absence due to injury or poisoning.

Sleep Apnea, Disability Pensions, and Cause-Specific Mortality: A Swedish Nationwide Register Linkage Study.

Sleep apnea is a common problem affecting daily functioning and health. We evaluated associations between sleep apnea and receipt of a disability pension and mortality in a prospective study of 74,543 cases of sleep apnea (60,125 outpatient, 14,418 inpatient) from the Swedish Patient Register (2000-2009 inclusive). Cases were matched to 5 noncases (n = 371,592) and followed from diagnosis/inclusion to December 31, 2010, via nationwide registers. During a mean follow-up period of 5.1 (standard deviation, 2.7) years, 13% of men and 21% of women with inpatient sleep apnea received a disability pension. Inpatient sleep apnea was associated with higher total mortality (for men, hazard ratio (HR) = 1.71, 95% confidence interval (CI): 1.59, 1.84; for women, HR = 2.33, 95% CI: 2.04, 2.67), with associations being strongest for deaths due to ischemic heart disease (for men, HR = 2.27, 95% CI: 1.94, 2.65; for women, HR = 5.27, 95% CI: 3.78, 7.34), respiratory disorders (for men, HR = 3.29, 95% CI: 2.45, 4.42; for women, HR= 5.24, 95% CI: 3.52, 7.81), and suicide (for men, HR = 1.76, 95% CI: 1.19, 2.60; for women, HR = 4.33, 95% CI: 1.96, 9.56). There were no associations of inpatient sleep apnea with cancer mortality. Outpatient sleep apnea was associated with a higher risk of receiving a disability pension but not higher total mortality. In conclusion, inpatient sleep apnea is related to a higher risk of disability pension receipt and mortality a decade after diagnosis.

Change in Job Strain as a Predictor of Change in Insomnia Symptoms: Analyzing Observational Data as a Non-randomized Pseudo-Trial.

Study objectives: To examine whether change in job strain leads to change in insomnia symptoms. Methods: Among 24873 adults (82% women, mean age 44 years) who participated in a minimum of three consecutive study waves (2000-2012), job strain was assessed at the first and second wave and insomnia symptoms at all three waves. We analyzed observational data as a "pseudo-trial" including participants with no job strain in the first wave and no insomnia symptoms in the first and second wave (n = 7354) to examine whether the onset of job strain between the first and second waves predicted the onset of insomnia symptoms in the third wave. We used a corresponding approach, including those with job strain in the first wave and insomnia symptoms in the first and second wave (n = 2332), to examine whether the disappearance of job strain between the first two waves predicted remission of insomnia symptoms in the third wave. Results: The onset of job strain predicted the onset of subsequent insomnia symptoms after adjustment for sex, age, marital status, education, smoking, physical activity, alcohol consumption, body mass index, and comorbidities (odds ratio compared to no onset of job strain 1.32, 95% CI 1.16-1.51). The disappearance of job strain was associated with lower odds of repeated insomnia symptoms (odds ratio compared to no disappearance of job strain 0.78, 95% CI 0.65-0.94). Further adjustment for shift work or sleep apnea did not change these associations. Conclusions: These results suggest that job strain is a modifiable risk factor for insomnia symptoms.

Job insecurity and risk of diabetes: a meta-analysis of individual participant data.

BACKGROUND: Job insecurity has been associated with certain health outcomes. We examined the role of job insecurity as a risk factor for incident diabetes. METHODS: We used individual participant data from 8 cohort studies identified in 2 open-access data archives and 11 cohort studies participating in the Individual-Participant-Data Meta-analysis in Working Populations Consortium. We calculated study-specific estimates of the association between job insecurity reported at baseline and incident diabetes over the follow-up period. We pooled the estimates in a meta-analysis to produce a summary risk estimate. RESULTS: The 19 studies involved 140 825 participants from Australia, Europe and the United States, with a mean follow-up of 9.4 years and 3954 incident cases of diabetes. In the preliminary analysis adjusted for age and sex, high job insecurity was associated with an increased risk of incident diabetes compared with low job insecurity (adjusted odds ratio [OR] 1.19, 95% confidence interval [CI] 1.09-1.30). In the multivariable-adjusted analysis restricted to 15 studies with baseline data for all covariates (age, sex, socioeconomic status, obesity, physical activity, alcohol and smoking), the association was slightly attenuated (adjusted OR 1.12, 95% CI 1.01-1.24). Heterogeneity between the studies was low to moderate (age- and sex-adjusted model: I2 = 24%, p = 0.2; multivariable-adjusted model: I2 = 27%, p = 0.2). In the multivariable-adjusted analysis restricted to high-quality studies, in which the diabetes diagnosis was ascertained from electronic medical records or clinical examination, the association was similar to that in the main analysis (adjusted OR 1.19, 95% CI 1.04-1.35). INTERPRETATION: Our findings suggest that self-reported job insecurity is associated with a modest increased risk of incident diabetes. Health care personnel should be aware of this association among workers reporting job insecurity.

Use of sleep medications and risk of cancer: a matched case-control study.

BACKGROUND: Previous research suggests a possible link between sleep-medication use and mortality, especially cancer deaths, but findings are mixed, and large population-based studies are lacking. METHODS: Data from the Finnish Public Sector study were linked to the Finnish Cancer Register and the Drug Prescription Register of Finland. A total of 5053 cancer cases (mean age of 57.4 years) diagnosed in 2002-2011, and their 24,388 controls free of cancer and matched for sex, age, socioeconomic status, employer, and geographical area, were identified. The use of sleep medications was defined as purchases of prescribed sleep medications. RESULTS: Both quantity and duration of prior sleep-medication use during the seven years studied were associated with increased odds of having cancer. Compared with participants not using sleep medications, the odds ratio was 1.18-fold (95% confidence interval (CI): 1.01-1.39) for those who used >100 defined daily doses per year and 1.16-fold (95% CI: 1.01-1.34) for those who had such a medication for >3 years. Site-specific analyses showed a more pronounced association of quantity and duration of sleep-medication use with subsequent cancer of the respiratory system (odds ratio for >100 defined daily doses per year vs. no use: 3.47; 95% CI: 1.97-6.11). No associations were found with other cancer sites. CONCLUSION: In this register-based study, sleep-medication use was associated with an increased cancer incidence of the respiratory system. Further studies are needed to examine potential carcinogenic mechanisms associated with hypnotic medications.

Onset of impaired sleep as a predictor of change in health-related behaviours; analysing observational data as a series of non-randomized pseudo-trials.

BACKGROUND: Changes in health-related behaviour may be a key mechanism linking impaired sleep to poor health, but evidence on this is limited. In this study, we analysed observational data to determine whether onset of impaired sleep is followed by changes in health-related behaviours. METHODS: We used data from 37,508 adults from the longitudinal Finnish Public Sector Study. In analysis of 59 152 person-observations on duration and quality of sleep and health-related behaviours (alcohol consumption, smoking, physical activity and weight control), data were treated as a series of non-randomized pseudo-trials with strict predefined criteria for data inclusion and temporality. RESULTS: Smokers who experienced onset of short sleep were less likely to quit smoking than those with persistent normal sleep [odds ratio (OR) = 0.78, 95% confidence interval (CI): 0.64-0.97]. Onset of short sleep also predicted initiating high-risk alcohol consumption (OR = 1.17, 95% CI: 1.00-1.37). Onset of disturbed sleep was associated with changes in all assessed health-related behaviours: initiation of high-risk alcohol consumption (OR = 1.23, 95% CI: 1.05-1.45), quitting smoking (OR = 0.80, 95% CI: 0.63-1.00), becoming physically inactive (OR = 1.17, 95% CI: 1.06-1.30) and becoming overweight or obese (OR = 1.12, 95% CI: 1.01-1.23). CONCLUSIONS: Findings suggest that the onset of short or disturbed sleep are risk factors for adverse changes in health-related behaviours. These findings highlight potential pathways linking impaired sleep to the development of lifestyle-related morbidity and mortality.

Insomnia as a risk factor for ill health: results from the large population-based prospective HUNT Study in Norway.

Insomnia co-occurs with many health problems, but less is known about the prospective associations. The aim of the current study was to investigate if insomnia predicts cumulative incidence of mental and physical conditions. Prospective population-based data from the two last Nord-Trøndelag Health Studies (HUNT2 in 1995­97 and HUNT3 in 2006­08), comprising 24 715 people in the working population, were used to study insomnia as a risk factor for incidence of physical and mental conditions. Insomnia was defined according to the 4th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). Insomnia at HUNT2 was a significant risk factor for incidence of a range of both mental and physical conditions at HUNT3 11 years later. Most effects were only slightly attenuated when adjusting for confounding factors, and insomnia remained a significant risk factor for the following conditions in the adjusted analyses: depression [odds ratio (OR): 2.38, 95% confidence interval (CI): 1.91­2.98], anxiety (OR: 2.08, 95% CI: 1.63­2.64), fibromyalgia (OR: 2.05, 95% CI: 1.51­2.79), rheumatoidarthritis (OR: 1.87, 95% CI: 1.29­2.52), whiplash (OR: 1.71, 95% CI: 1.21­2.41), arthrosis (OR: 1.68, 95% CI: 1.43­1.98), osteoporosis (OR:1.52, 95% CI: 1.14­2.01, headache (OR: 1.50, 95% CI: 1.16­1.95,asthma (OR: 1.47, 95% CI: 1.16­1.86 and myocardial infarction (OR:1.46, 95% CI: 1.06­2.00). Insomnia was also associated significantly with incidence of angina, hypertension, obesity and stroke in the crude analyses, but not after adjusting for confounders. We conclude that insomnia predicts cumulative incidence of several physical and mental conditions. These results may have important clinical implications, and whether or not treatment of insomnia would have a preventive value for both physical and mental conditions should be studied further.

Age-related trajectories of physical functioning in work and retirement: the role of sociodemographic factors, lifestyle and disease.

BACKGROUND: Loss of physical functioning is an early marker of declining health in older people. The objective of this study was to examine the age-related trajectories of physical functioning among those in full-time work and retirement. METHODS: Based on the Health and Retirement Study, participants who were working full-time or were in full-time retirement and 65-85 years of age during the follow-up period from 1992 to 2010 were included (n=17 844, n of observations from repeated measures in full-time work 5891 and in retirement 57 117). Details of physical functioning were asked about at all study phases and 10 items related to mobility and activities of daily living were summed to obtain a physical functioning score (0-10). RESULTS: The number of physical functioning difficulties increased every 10 years by 0.17 (95% CI 0.04 to 0.29) when in full-time work and by 0.46 (95% CI 0.41 to 0.50) in retirement after adjusting for age, sex, race, education, total wealth, Body Mass Index, smoking, physical activity and number of diseases. Factors that were associated with a significantly greater increase in number of physical functioning difficulties in full-time work and retirement include lifestyle-related risks and chronic conditions. CONCLUSIONS: Physical functioning declines faster in retirement than in full-time work in employees aged 65 years or older and the difference is not explained by absence of chronic diseases and lifestyle-related risks.

Symptoms of sleep disordered breathing and risk of cancer: a prospective cohort study.

STUDY OBJECTIVES: Sleep disordered breathing (SDB) has been associated with oxidative stress, inflammation, and altered hormonal levels, all of which could affect the risk of cancer. The aim of the study is to examine if symptoms of SDB including snoring, breathing cessations, and daytime sleepiness affect the incidence of total cancer and subtypes of cancer. DESIGN: Prospective cohort study. SETTING: The third wave (1991-1993) of the Copenhagen City Heart Study. PARTICIPANTS: There were 8,783 men and women in whom cancer had not been previously diagnosed. MEASUREMENTS AND RESULTS: Participants answered questions about snoring and breathing cessations in 1991-1993, whereas information about daytime sleepiness based on the Epworth Sleepiness Scale was collected in a subset of the participants (n = 5,894) in 1998. First-time incidence of cancer was followed until December 2009 in a nationwide cancer register. We found no overall association between symptoms of SDB and incident cancer. Yet, in the small group with high daytime sleepiness, we observed a surprisingly higher cancer incidence (hazard ratio = 4.09; 95% CI 1.58-10.55) in persons younger than 50 years. We also found a higher risk of virus/immune-related cancers (2.73; 1.27-5.91) and alcohol-related cancers (4.92; 1.45-16.76) among persons with daytime sleepiness. More SDB symptoms were associated with a higher risk of smoking-related cancers (Ptrend: 0.04). Apart from these findings there were no clear associations between symptoms of sleep disordered breathing and cancer subtypes. CONCLUSION: We found very limited evidence of relationship between symptoms of sleep disordered breathing and incidence of cancer.

Job strain and health-related lifestyle: findings from an individual-participant meta-analysis of 118,000 working adults.

OBJECTIVES: We examined the associations of job strain, an indicator of work-related stress, with overall unhealthy and healthy lifestyles. METHODS: We conducted a meta-analysis of individual-level data from 11 European studies (cross-sectional data: n = 118,701; longitudinal data: n = 43,971). We analyzed job strain as a set of binary (job strain vs no job strain) and categorical (high job strain, active job, passive job, and low job strain) variables. Factors used to define healthy and unhealthy lifestyles were body mass index, smoking, alcohol intake, and leisure-time physical activity. RESULTS: Individuals with job strain were more likely than those with no job strain to have 4 unhealthy lifestyle factors (odds ratio [OR] = 1.25; 95% confidence interval [CI] = 1.12, 1.39) and less likely to have 4 healthy lifestyle factors (OR = 0.89; 95% CI = 0.80, 0.99). The odds of adopting a healthy lifestyle during study follow-up were lower among individuals with high job strain than among those with low job strain (OR = 0.88; 95% CI = 0.81, 0.96). CONCLUSIONS: Work-related stress is associated with unhealthy lifestyles and the absence of stress is associated with healthy lifestyles, but longitudinal analyses suggest no straightforward cause-effect relationship between work-related stress and lifestyle.

Associations of job strain and lifestyle risk factors with risk of coronary artery disease: a meta-analysis of individual participant data.

BACKGROUND: It is unclear whether a healthy lifestyle mitigates the adverse effects of job strain on coronary artery disease. We examined the associations of job strain and lifestyle risk factors with the risk of coronary artery disease. METHODS: We pooled individual-level data from 7 cohort studies comprising 102 128 men and women who were free of existing coronary artery disease at baseline (1985-2000). Questionnaires were used to measure job strain (yes v. no) and 4 lifestyle risk factors: current smoking, physical inactivity, heavy drinking and obesity. We grouped participants into 3 lifestyle categories: healthy (no lifestyle risk factors), moderately unhealthy (1 risk factor) and unhealthy (2-4 risk factors). The primary outcome was incident coronary artery disease (defined as first nonfatal myocardial infarction or cardiac-related death). RESULTS: There were 1086 incident events in 743,948 person-years at risk during a mean follow-up of 7.3 years. The risk of coronary artery disease among people who had an unhealthy lifestyle compared with those who had a healthy lifestyle (hazard ratio [HR] 2.55, 95% confidence interval [CI] 2.18-2.98; population attributable risk 26.4%) was higher than the risk among participants who had job strain compared with those who had no job strain (HR 1.25, 95% CI 1.06-1.47; population attributable risk 3.8%). The 10-year incidence of coronary artery disease among participants with job strain and a healthy lifestyle (14.7 per 1000) was 53% lower than the incidence among those with job strain and an unhealthy lifestyle (31.2 per 1000). INTERPRETATION: The risk of coronary artery disease was highest among participants who reported job strain and an unhealthy lifestyle; those with job strain and a healthy lifestyle had half the rate of disease. A healthy lifestyle may substantially reduce disease risk among people with job strain.

Work stress and risk of cancer: meta-analysis of 5700 incident cancer events in 116,000 European men and women.

OBJECTIVE: To investigate whether work related stress, measured and defined as job strain, is associated with the overall risk of cancer and the risk of colorectal, lung, breast, or prostate cancers. DESIGN: Meta-analysis of pooled prospective individual participant data from 12 European cohort studies including 116,056 men and women aged 17-70 who were free from cancer at study baseline and were followed-up for a median of 12 years. Work stress was measured and defined as job strain, which was self reported at baseline. Incident cancers (all n=5765, colorectal cancer n=522, lung cancer n=374, breast cancer n=1010, prostate cancer n=865) were ascertained from cancer, hospital admission, and death registers. Data were analysed in each study with Cox regression and the study specific estimates pooled in meta-analyses. Models were adjusted for age, sex, socioeconomic position, body mass index (BMI), smoking, and alcohol intake RESULTS: A harmonised measure of work stress, high job strain, was not associated with overall risk of cancer (hazard ratio 0.97, 95% confidence interval 0.90 to 1.04) in the multivariable adjusted analyses. Similarly, no association was observed between job strain and the risk of colorectal (1.16, 0.90 to 1.48), lung (1.17, 0.88 to 1.54), breast (0.97, 0.82 to 1.14), or prostate (0.86, 0.68 to 1.09) cancers. There was no clear evidence for an association between the categories of job strain and the risk of cancer. CONCLUSIONS: These findings suggest that work related stress, measured and defined as job strain, at baseline is unlikely to be an important risk factor for colorectal, lung, breast, or prostate cancers.

Job strain as a risk factor for coronary heart disease: a collaborative meta-analysis of individual participant data.

BACKGROUND: Published work assessing psychosocial stress (job strain) as a risk factor for coronary heart disease is inconsistent and subject to publication bias and reverse causation bias. We analysed the relation between job strain and coronary heart disease with a meta-analysis of published and unpublished studies. METHODS: We used individual records from 13 European cohort studies (1985-2006) of men and women without coronary heart disease who were employed at time of baseline assessment. We measured job strain with questions from validated job-content and demand-control questionnaires. We extracted data in two stages such that acquisition and harmonisation of job strain measure and covariables occurred before linkage to records for coronary heart disease. We defined incident coronary heart disease as the first non-fatal myocardial infarction or coronary death. FINDINGS: 30,214 (15%) of 197,473 participants reported job strain. In 1·49 million person-years at risk (mean follow-up 7·5 years [SD 1·7]), we recorded 2358 events of incident coronary heart disease. After adjustment for sex and age, the hazard ratio for job strain versus no job strain was 1·23 (95% CI 1·10-1·37). This effect estimate was higher in published (1·43, 1·15-1·77) than unpublished (1·16, 1·02-1·32) studies. Hazard ratios were likewise raised in analyses addressing reverse causality by exclusion of events of coronary heart disease that occurred in the first 3 years (1·31, 1·15-1·48) and 5 years (1·30, 1·13-1·50) of follow-up. We noted an association between job strain and coronary heart disease for sex, age groups, socioeconomic strata, and region, and after adjustments for socioeconomic status, and lifestyle and conventional risk factors. The population attributable risk for job strain was 3·4%. INTERPRETATION: Our findings suggest that prevention of workplace stress might decrease disease incidence; however, this strategy would have a much smaller effect than would tackling of standard risk factors, such as smoking. FUNDING: Finnish Work Environment Fund, the Academy of Finland, the Swedish Research Council for Working Life and Social Research, the German Social Accident Insurance, the Danish National Research Centre for the Working Environment, the BUPA Foundation, the Ministry of Social Affairs and Employment, the Medical Research Council, the Wellcome Trust, and the US National Institutes of Health.

Job strain and tobacco smoking: an individual-participant data meta-analysis of 166,130 adults in 15 European studies.

BACKGROUND: Tobacco smoking is a major contributor to the public health burden and healthcare costs worldwide, but the determinants of smoking behaviours are poorly understood. We conducted a large individual-participant meta-analysis to examine the extent to which work-related stress, operationalised as job strain, is associated with tobacco smoking in working adults. METHODOLOGY AND PRINCIPAL FINDINGS: We analysed cross-sectional data from 15 European studies comprising 166,130 participants. Longitudinal data from six studies were used. Job strain and smoking were self-reported. Smoking was harmonised into three categories never, ex- and current. We modelled the cross-sectional associations using logistic regression and the results pooled in random effects meta-analyses. Mixed effects logistic regression was used to examine longitudinal associations. Of the 166,130 participants, 17% reported job strain, 42% were never smokers, 33% ex-smokers and 25% current smokers. In the analyses of the cross-sectional data, current smokers had higher odds of job strain than never-smokers (age, sex and socioeconomic position-adjusted odds ratio: 1.11, 95% confidence interval: 1.03, 1.18). Current smokers with job strain smoked, on average, three cigarettes per week more than current smokers without job strain. In the analyses of longitudinal data (1 to 9 years of follow-up), there was no clear evidence for longitudinal associations between job strain and taking up or quitting smoking. CONCLUSIONS: Our findings show that smokers are slightly more likely than non-smokers to report work-related stress. In addition, smokers who reported work stress smoked, on average, slightly more cigarettes than stress-free smokers.

Health risk behaviors and morbidity among hospital staff--comparison across hospital ward medical specialties in a study of 21 Finnish hospitals.

OBJECTIVE: This study examined whether indicators of poor health and health risk behaviors among hospital staff differ between the ward specialties. METHODS: Across 21 hospitals in Finland, 8003 employees (mean age 42 years, 87% women, 86% nurses) working in internal medicine, surgery, obstetrics and gynecology, pediatrics, intensive care, and psychiatry responded to a baseline survey on health and health risk behaviors (response rate 70%). Responses were linked to records of sickness absence and medication over the following 12 months. RESULTS: Psychiatric staff had higher odds of smoking [odds ratio (OR) 2.58, 95% confidence interval (95% CI) 2.14-3.12], high alcohol use (OR 1.55, 95% CI 1.21-1.99), physical inactivity (OR 1.30, 95% CI 1.11-1.53), chronic physical disease (OR 1.19, 95% CI 1.04-1.36), current or past mental disorders (OR 1.81, 95% CI 1.50-2.17), and co-occurring poor health indicators (OR 2.65, 95% CI 2.08-3.37) as compared to those working in other specialties. They also had higher odds of sickness absence due to mental disorders (OR 1.40, 95% CI 1.02-1.92) and depression (OR 1.61, 95% CI 1.02-2.55) at follow-up after adjustment for baseline health and covariates. Personnel in surgery had the lowest probability of morbidity. No major differences between specialties were found in the use of psychotropic medication. CONCLUSION: The prevalence of hospital employees with an adverse health risk profile is higher in psychiatric wards than other specialties.