When reciprocity fails: effort-reward imbalance in relation to coronary heart disease and health functioning within the Whitehall II study

Developing strategic interventions to reduce cardiovascular disease risk among law enforcement officers: the art and science of data triangulation

The purpose of this study was to use data triangulation to inform interventions targeted at reducing morbidity from cardiovascular disease (CVD) and associated risk factors among law enforcement officers. Using the Precede-Proceed Health Promotion Planning Model, survey data (n = 672) and focus group data (n = 8 groups) from the Milwaukee Police Department were analyzed. Narrative transcripts disclosed that law enforcement officers encounter potential barriers and motivators to a healthy lifestyle. Survey results indicated rates of overweight (71.1% vs. 60.8%) and hypertension (27.4% vs. 17.6%) were significantly (p < or = .001) higher among Milwaukee Police Department law enforcement officers than the general population of Wisconsin (n = 2,855). The best predictor of CVD was diabetes (p = .030). Occupational health nurses are uniquely positioned to identify health risks, design appropriate interventions, and advocate for policy changes that improve the health of those employed in law enforcement and other high-risk professions.

Work stress and reduced health in young physicians: prospective evidence from Swiss residents

OBJECTIVES

Job stress, investigated by the effort-reward model in various working environments in different countries, has been widely reported, yet studies addressing physicians are lacking. The present study investigated the perceived job stress, its association with the amount of working hours, and its impact on young physicians' self-reported health and their satisfaction with life during residency.

METHODS

In a prospective study design, a cohort of Swiss medical school graduates was followed up, beginning in 2001. In their second and fourth years of residency, 433 physicians assessed their effort-reward imbalance, overcommitment, physical and mental well-being and satisfaction in life. Taking the longitudinal design into account, four categories of stressed residents were defined: (1) subjects not reporting high work stress at either measurement, (2) subjects reporting high work stress in the second but not in the fourth year of residency, (3) subjects with onset of high work stress in fourth year and (4) residents reporting high work stress at both measurements.

RESULTS

All components of the perceived stress at work were significantly correlated with the amount of working hours, effort showing the highest correlation. While two-thirds of the participants do not report high work stress, assessed by the extrinsic part of the effort-reward imbalance model (the ratio between effort and reward) and 12% show a decrease of stress over time, there are 15% with an increase of stress over time, and 10% with persistently high stress experience. In terms of the intrinsic stress component (overcommitment), 71% show low values, 12% show a decrease, 9% an increase and 8% constantly high values. The groups with constant and increasing extrinsic and intrinsic stress experience exhibit significantly worse health and life satisfaction compared to the remaining groups, after controlling for gender and baseline health.

CONCLUSIONS

Stress at work in young physicians, especially when being experienced over a longer period in postgraduate training, has to be a matter of concern because of its negative impact on health and life satisfaction and the risk of developing symptoms of burnout in the long run.

Effort-reward imbalance, heart rate, and heart rate variability: the Cardiovascular Risk in Young Finns Study

BACKGROUND

Work stress indicated by effort-reward imbalance is hypothesized to cause autonomic arousal, which, if prolonged or frequent, could contribute to cardiovascular pathology. However, only limited empirical evidence on this mechanism is available.

PURPOSE

This study examined associations between effort-reward imbalance, heart rate (HR), and heart rate variability (HRV).

METHOD

The participants were 457 women and 406 men (mean age 32.3 years) derived from the population-based Young Finns Study. Effort-reward imbalance was defined as the ratio between effort and reward, higher efforts compared to rewards indicating greater imbalance.

RESULTS

In age-adjusted regression models, higher effort-reward imbalance was associated with lower HRV, and lower reward was associated with higher HR among women. These associations were not attenuated after additional adjustments for demographic characteristics and coronary risk factors. No significant associations of effort-reward imbalance or its components with HR and HRV were found in men.

CONCLUSION

Our finding of lower HRV and higher HR in young healthy women with high effort-reward imbalance and low rewards provides evidence of a potential mechanism that may link effort-reward imbalance to the development of coronary heart disease (CHD) in women.

Higher overcommitment to work is associated with lower norepinephrine secretion before and after acute psychosocial stress in men

BACKGROUND

Overcommitment (OC) is a pattern of excessive striving. In reaction to work stress, OC has been associated with higher sympathetic nervous system activation and cortisol release, but data on neuroendocrine reactivity to standardized stressors are scarce. We investigated whether OC is associated with differential levels of the stress hormones norepinephrine and cortisol in response to acute psychosocial stress.

METHODS

Fifty-eight medication-free non-smoking men aged between 20 and 65 years (mean+/-S.E.M.: 36.3+/-1.8) underwent an acute standardized psychosocial stress task combining public speaking and mental arithmetic in front of an audience. We assessed OC as well as a variety of psychological control variables including vital exhaustion, perfectionism, chronic stress, and cognitive stress appraisal. Moreover, we measured plasma norepinephrine as well as salivary cortisol before and after stress and several times up to 60 min thereafter.

RESULTS

Higher OC was associated with lower baseline norepinephrine levels (r = -0.37, p < 0.01). General linear models controlling for age, BMI, and mean arterial blood pressure revealed that higher overcommitment was associated with lower norepinephrine and cortisol levels before and after stress (p's < 0.02) as well as with lower norepinephrine stress reactivity (p = 0.02). Additional controlling for the potential psychological confounders vital exhaustion, perfectionism, chronic stress, and depression confirmed lower norepinephrine levels before and after stress (p < 0.01) as well lower norepinephrine stress reactivity (p = 0.02) with increasing OC. Higher OC independently explained 13% of the total norepinephrine stress response (beta = -0.46, p < 0.01, R(2) change = 0.13).

CONCLUSIONS

Our findings suggest blunted increases in norepinephrine following stress with increasing OC potentially mirroring blunted stress reactivity of the sympathetic nervous system.

Effort-reward imbalance at work and driving anger in an Australian community sample: is there a link between work stress and road rage?

Both workplace stress and road rage are reported to be on the increase. This study examined the effort-reward imbalance (ERI) model of work stress and its relationship with general anger and driving anger in a community sample of 130 Australian workers. It also examined international differences in driving anger, with Australian motorists reporting lower levels of driving anger than American motorists but higher levels than British motorists. Hierarchical multiple regressions confirmed ERI increased driving anger via the mediating variables of general anger and overcommitment; individuals suffering ERI may develop increased general anger or overcommitment, in turn increasing propensity to experience driving anger. Regressions also showed that overcommitment (but not general anger) moderated the effect of ERI on driving anger; ERI has a greater influence on increasing driving anger in individuals with high overcommitment at work. The results have considerable implications for the safety and emotional health of individuals who perceive an imbalance between their efforts and rewards at work, and overcommitted individuals may be at greater risk. The wider implications of the relationship between work stress, emotional well-being and driving anger in employees, along with the potential of driver education interventions, are discussed as public health issues.

Effort-reward imbalance and relational injustice at work predict sickness absence: the Whitehall II study

OBJECTIVES

Sickness absence is a major occupational health problem, but evidence for associations between potentially modifiable psychosocial work factors and sickness absence is still scarce. We studied the impact of relational justice and effort-reward imbalance on subsequent rates of sickness absence.

METHODS

The Whitehall II prospective cohort study of British civil servants, 10,308 men and women, was established between 1985 and 1988. Indicators of effort-reward imbalance and the relational component of organizational justice were constructed from questions included at baseline. Participants were classified into three groups (low, intermediate, and high) for both effort-reward imbalance and relational justice. Short (< or =7 days) and long (>7 days) spells of sickness absence during 1985-1989 and 1991-1995 were used to study immediate and longer term effects of work characteristics.

RESULTS

After adjustment for age, employment grade, and baseline health, men and women with low relational justice had increased risks of long spells of sickness absence of 14% and 28% in comparison to men and women experiencing high levels of justice. Similar effect sizes (25% and 21%) were found for high vs. low effort-reward imbalance. Both work measures also predicted short spells of sickness absence. Effort-reward imbalance (men and women) and relational justice (women only) each predicted long spells of sickness absence independently of the other.

CONCLUSIONS

Both relational justice and effort-reward imbalance are important determinants of sickness absence. Workplace interventions to improve these aspects of working conditions have the potential to reduce levels of sickness absence.

Unfairness and the social gradient of metabolic syndrome in the Whitehall II Study

OBJECTIVES

Little work has investigated the relationship between unfairness and risk factors for heart disease. We examine the role of unfairness in predicting the metabolic syndrome and explaining the social gradient of the metabolic syndrome.

METHODS

The design is a prospective study with an average follow-up of 5.8 years. Participants were 4128 males and 1715 females of 20 civil service departments in London (Whitehall II study). Sociodemographics, unfairness, employment grade, behavioral risk factors, and other psychosocial factors were measured at baseline (Phase 3, 1991-1993). Waist circumference, triglycerides, high-density lipoprotein (HDL) cholesterol, fasting glucose, and hypertension were used to define metabolic syndrome at follow-up (Phase 5, 1997-2000), according to the National Cholesterol Education Program/Adult Treatment Panel III guidelines.

RESULTS

Unfairness is positively associated with waist circumference, hypertension, triglycerides, and fasting glucose and negatively associated with serum HDL cholesterol. High levels of unfairness are also associated with the metabolic syndrome [odds ratio (OR)=1.72, 95% CI=1.31-2.25], after adjustment for age and gender. After additional adjustment for employment grade, behavioral risk factors, and other psychosocial factors, the relationship between high unfairness and metabolic syndrome weakened but remained significant (OR=1.37, 95% CI=1.00-1.93). When adjusting for unfairness, the social gradient of metabolic syndrome was reduced by approximately 10%.

CONCLUSION

Unfairness may be a risk factor for the metabolic syndrome and its components. Future research is needed to study the biological mechanisms linking unfairness and the metabolic syndrome.

Unfairness and health: evidence from the Whitehall II Study

OBJECTIVE

To examine the effects of unfairness on incident coronary events and health functioning.

DESIGN

Prospective cohort study. Unfairness, sociodemographics, established coronary risk factors (high serum cholesterol, hypertension, obesity, exercise, smoking and alcohol consumption) and other psychosocial work characteristics (job strain, effort-reward imbalance and organisational justice) were measured at baseline. Associations between unfairness and incident coronary events and health functioning were determined over an average follow-up of 10.9 years.

PARTICIPANTS

5726 men and 2572 women from 20 civil service departments in London (the Whitehall II Study).

MAIN OUTCOME MEASURES

Incident fatal coronary heart disease, non-fatal myocardial infarction and angina (528 events) and health functioning.

RESULTS

Low employment grade is strongly associated with unfairness. Participants reporting higher levels of unfairness are more likely to experience an incident coronary event (HR 1.55, 95% CI 1.11 to 2.17), after adjustment for age, gender, employment grade, established coronary risk factors and other work-related psychosocial characteristics. Unfairness is also associated with poor physical (OR 1.46, 95% CI 1.20 to 1.77) and mental (OR 1.54, 95% CI 1.19 to 1.99) functioning at follow-up, controlling for all other factors and health functioning at baseline.

CONCLUSIONS

Unfairness is an independent predictor of increased coronary events and impaired health functioning. Further research is needed to disentangle the effects of unfairness from other psychosocial constructs and to investigate the societal, relational and biological mechanisms that may underlie its associations with health and heart disease.

Relations of occupational stress to occupational class in Japanese civil servants--analysis by two occupational stress models

The aim of the present study was to identify relations between occupational stress and occupational class in Japanese civil servants, using two occupational stress models-the Effort-Reward Imbalance (ERI) Model and the Job Demand-Control (JDC) Model. The subjects were employees of three local public organizations. We distributed self-administered questionnaires and assessed occupational stress by ERI and JDC. We used seven occupational categories based on the Standard Occupational Classification for Japan. The data of 6,423 male and 1,606 female subjects were analyzed by logistic regression analysis to obtain odds ratios (OR) for relations between occupational stress and occupational class. In JDC, male clerical workers, transport/communication workers and protective service workers showed a significantly higher OR of being in the high occupational stress group, compared to managers. In ERI, male professionals/technicians, transport/communication workers, clerical workers and protective service workers showed a significantly higher prevalence OR, compared to managers, the two models giving different results. In ERI, female production workers/laborers and clerical workers had a significantly lower prevalence OR, compared to managers. The results of this study showed that occupational stress differed by occupational class and the two occupational stress models gave different results for occupational classes with high occupational stress.

Psychosocial determinants of premature cardiovascular mortality differences within Hungary

OBJECTIVES

The life expectancy gap between Central-Eastern European (CEE) countries, including Hungary, and Western Europe (WE) is mainly attributable to excess cardiovascular (CV) mortality in midlife. This study explores the contribution of socioeconomic, work related, psychosocial, and behavioural variables to explaining variations of middle aged male and female CV mortality across 150 sub-regions in Hungary.

DESIGN

Cross sectional, ecological analyses.

SETTING

150 sub-regions of Hungary.

PARTICIPANTS AND METHODS

12 643 people were interviewed in Hungarostudy 2002 survey, representing the Hungarian population according to sex, age, and sub-regions. Independent variables were income, education, control in work, job insecurity, weekend working hours, social support, depression, hostility, anomie, smoking, body mass index, and alcohol misuse.

MAIN OUTCOME MEASURES

Gender specific standardised premature (45-64 years) total CV, ischaemic heart disease, and cerebrovascular mortality rates in 150 sub-regions of Hungary.

RESULTS

Low education and income were the most important determinants of mid-aged CV mortality differences across sub-regions. High weekend workload, low social support at work, and low control at work account for a large part of variation in male premature CV mortality rates, whereas job insecurity, high weekend workload, and low control at work contribute most noticeably to variations in premature CV mortality rates among women. Low social support from friends, depression, anomie, hostility, alcohol misuse and cigarette smoking can also explain a considerable part of variations of premature CV mortality differences.

CONCLUSION

Variations in middle aged CV mortality rates in a rapidly changing society in CEE are largely accounted for by distinct unfavourable working and other psychosocial stress conditions.

Psychometric properties of the Korean version of the effort–reward imbalance questionnaire: a study in a petrochemical company

OBJECTIVE

To evaluate the criterion validity, factorial validity, and internal consistency of Korean version of effort-reward imbalance (ERI) for the scales of effort, reward, and overcommitment as well as to examine the effect of psychosocial factors on physical and mental illness among petroleum refinery workers in South Korea.

METHODS

The Korean version of ERI questionnaire was constructed using the translation and back-translation technique, and its psychometric properties were explored among 908 male workers in a large petroleum refinery in South Korea in 2002. Cronbach's alpha coefficient was used to test internal consistency. An exploratory factor analysis was conducted on all items of the instrument. Confirmatory factor analyses were conducted on each dimension of effort, reward and overcommitment. Physical and mental health was measured by self-rated health (SF-8). The lowest tertiles of the scores were defined as illness. Multiple logistic regression models were used to test the effect of job stress on the physical and mental health (criterion validity of ERI scales).

RESULTS

The Cronbach's alpha coefficients for effort, reward, and overcommitment were 0.71, 0.86, and 0.75, respectively, indicating satisfactory internal consistency. Exploratory factor analysis found three latent factors, which closely corresponded to the theoretical structure of the ERI model. Acceptable construct validity was shown using confirmatory factor analysis. The highest tertile of effort-reward ratio was significantly associated with physical illness (OR 2.4, 95% CI 1.7-3.6) and mental illness (OR 2.9, 95% CI 2.0-4.2), compared to lower tertiles. Overcommitment was significantly associated with mental illness, but not with physical illness.

CONCLUSIONS

These findings contribute to the validity and reliability of the Korean ERI questionnaire. Importantly, in the context of a rapid change in the labour market, the lack of reciprocity between efforts and rewards at work is strongly associated with self-rated physical and mental health.

Neuroendocrine and cardiovascular correlates of positive affect measured by ecological momentary assessment and by questionnaire

The relationships between positive affect, salivary cortisol over the day, and cardiovascular responses to laboratory mental stress tests, were assessed in 72 healthy non-smoking men (mean age 33.6+/-8.8 years). Positive affect was measured by aggregating ecological momentary assessments (EMA) of happiness obtained at four times on each of 2 working days, and by questionnaire using the Positive and Negative Affect Schedule (PANAS). Saliva was sampled on 2 days, on waking, 30 and 60 min later, and four other times over the day. Blood pressure and heart rate responses to speech and mirror tracing tasks were measured over two sessions 4 weeks apart. Data were analysed using regression of positive affect on biology adjusting for age, body mass and negative affect, with additional adjustment for time of waking in cortisol analyses and for work stress in cardiovascular analyses. EMA positive affect was inversely associated with cortisol early in the day and with the cortisol increase after waking, controlling for age, body mass index, and negative affect (P=0.012). There was no relationship between PANAS positive affect and cortisol, or between EMA positive affect and cortisol later in the day. Diastolic pressure recovery post-stress was more rapid among participants with high positive affect (P=0.022) and with lower systolic pressure throughout the stress sessions, after controlling for covariates including negative affect. PANAS positive affect was also inversely associated with systolic pressure, but not with diastolic stress or heart rate. We conclude that positive affect is related to biological responses in the laboratory and everyday life that may be health protective. Effects were substantially stronger when positive affect was assessed by aggregating EMA samples than with questionnaire measures.

Epidemiology of work related neck and upper limb problems: psychosocial and personal risk factors (part I) and effective interventions from a bio behavioural perspective (part II)

Work related neck and upper limb symptoms have a multi-factorial origin. Possible risk factors are of a physical, psychosocial or personal origin. These factors can reinforce each other and their influence can also be mediated by cultural or societal factors. Initially, most research on neck and upper limb symptoms focused on work-related physical exposure. Nowadays, psychosocial work characteristics are recognized as important risk factors. Various models have been developed to offer frameworks for possible pathways, but their empirical support is still not conclusive. In part I of this paper an overview is presented of the results of recent epidemiological studies on work related psychosocial and personal risk factors for neck and upper limb symptoms. In addition, the interplay between these factors and the possible intermediate role of an individuals work style in this process is explored. In contrast to previous reviews, it is now possible to base the conclusions on the effect of work related psychosocial factors on neck and upper limb symptoms on quite a few longitudinal studies. These studies show that high work demands or little control at work are often related to these symptoms. However, this relationship is neither very strong nor very specific. Perceived stress is studied in not as many studies but more consistently related to neck and upper limb symptoms. This also applies to general distress or other pain (co-morbidity). Job dissatisfaction does not contribute to neck and upper limb symptoms. Too little research on personal characteristics is available to draw any conclusions. It is plausible that behavioural aspects, such as work style, are of importance in the etiology of work related upper limb symptoms. However, studies concerning these factors are promising but too scarce to draw conclusions. Future studies should address these behavioural aspects. In part II, the recent studies on the effectiveness of preventive measures for work related neck and upper limb problems are discussed. Few randomised or non randomised controlled trials have been carried out to evaluate the effectiveness of individual or organisational interventions to improve work related psychosocial factors. Very few have reported on the preventive effect for work related neck and upper limb symptoms. Therefore, there is a great need for additional high quality trials before any conclusions on effectiveness of bio-behavioural interventions for reduction of neck and upper limb problems and return to work after these symptoms can be made. From the low back pain intervention research can be learned that interventions should best be targeted to both the worker and the organisation and that interventions will only be successful when all stakeholders are involved.

The influence of socioeconomic factors on cardiovascular disease risk factors in the context of economic development in the Samoan archipelago

Early in economic development there are positive associations between socioeconomic status (SES) and cardiovascular disease (CVD) risk factors, and in the most developed market economy societies there are negative associations. The purpose of this report is to describe cross-sectional and longitudinal associations between indicators of SES and CVD risk factors in a genetically homogenous population of Samoans at different levels of economic development. At baseline 1289 participants 25-58yrs, and at 4-year follow-up, 963 participants were studied in less economically developed Samoa and in more developed American Samoa. SES was assessed by education, occupation, and material lifestyle at baseline. The CVD risk factors, obesity, type-2 diabetes and hypertension were measured at baseline and 4-year follow-up, and an index of any incident CVD risk factor at follow-up was calculated. Sex and location (Samoa and American Samoa) specific multivariable logistic regression models were used to test for relationships between SES and CVD risk factors at baseline after adjustment for age and the other SES indicators. In addition an ordinal SES index was constructed for each individual based on all three SES indicators, and used in a multivariable model to estimate the predicted probability of CVD risk factors across the SES index for the two locations. In both the models using specific SES measures and CVD risk factor outcomes, and the models using the ordinal SES index and predicted probabilities of CVD risk factors, we detected a pattern of high SES associated with: (1) elevated odds of CVD risk factors in less developed Samoa, and (2) decreased odds of CVD risk factors in more developed American Samoa. We conclude that the pattern of inverse associations between SES and CVD risk factors in Samoa and direct associations in American Samoa is attributable to the heterogeneity across the Samoas in specific exposures to social processes of economic development and the natural history of individual CVD risk factors. The findings suggest that interventions on non-communicable diseases in the Samoas must be devised based on the level of economic development, the socio-economic context of risk factor exposures, and individual characteristics such as age, sex and education level.

Injustice at work and incidence of psychiatric morbidity: the Whitehall II study

BACKGROUND

Previous studies of organisational justice and mental health have mostly examined women and have not examined the effect of change in justice.

AIM

To examine effects of change in the treatment of employees by supervisors (the relational component of organisational justice) on minor psychiatric morbidity, using a cohort with a large proportion of men.

METHODS

Data are from the Whitehall II study, a prospective cohort of 10 308 white-collar British civil servants (3143 women and 6895 men, aged 35-55 at baseline) (Phase 1, 1985-88). Employment grade, relational justice, job demands, job control, social support at work, effort-reward imbalance, physical illness, and psychiatric morbidity were measured at baseline. Relational justice was assessed again at Phase 2 (1989-90). The outcome was cases of psychiatric morbidity by Phases 2 and 3 (1991-93) among participants case-free at baseline.

RESULTS

In analyses adjusted for age, grade, and baseline physical illness, women and men exposed to low relational justice at Phase 1 were at higher risk of psychiatric morbidity by Phases 2 and 3. Adjustment for other psychosocial work characteristics, particularly social support and effort-reward imbalance, partially attenuated these associations. A favourable change in justice between Phase 1 and Phase 2 reduced the immediate risk (Phase 2) of psychiatric morbidity, while an adverse change increased the immediate and longer term risk (Phase 3).

CONCLUSION

This study shows that unfair treatment by supervisors increases risk of poor mental health. It appears that the employers' duty to ensure that employees are treated fairly at work also has benefits for health.

The effects of effort-reward imbalance on inflammatory and cardiovascular responses to mental stress

OBJECTIVE

We examined the influence of effort-reward imbalance, a stressful feature of the work environment, on cardiovascular and inflammatory responses to acute mental stress.

METHODS

Ninety-two healthy men (mean age, 33.1 years) in full-time employment were recruited. Effort-reward imbalance was measured using a self-administered questionnaire. Blood, for the analysis of C-reactive protein (CRP) and von Willebrand factor (vWF) antigen, was sampled at baseline and 10 minutes after two mental stress tasks, whereas cardiovascular activity was measured throughout.

RESULTS

Plasma CRP and vWF were significantly elevated following the stress period, and cardiovascular activity was increased during and after both tasks (p < .001). Multiple linear regression analysis adjusted for age, body mass index, and baseline levels revealed that men with higher effort-reward imbalance demonstrated greater CRP and vWF responses to the stress tasks but blunted cardiovascular responses. Inflammatory and cardiovascular responses to stress appeared to be unrelated.

CONCLUSIONS

These findings suggest that the association between chronic work stress and cardiovascular disease risk may be mediated in part by heightened acute inflammatory responsivity. These responses appear not to result from differences in sympathoadrenal activation.

Psychosocial work stress is associated with poor self-rated health in Danish nurses: a test of the effort-reward imbalance model

Nursing staff are exposed to stressful work load which in turn is associated with poor physical and psychological health, sickness absence and job exit. The effort-reward imbalance (ERI) model is a validated approach to measure chronic psychosocial work stress by identifying nonreciprocity between occupational efforts spent and rewards received, and has been found to predict poor health. The aim of this cross-sectional study (n = 367 nurses and nurses aides) was first to test the psychometric properties of the Danish questionnaire measuring ERI, and secondly to analyse whether psychosocial work stress is associated with six indicators of poor self-rated health. Results derived from confirmatory factor analysis indicate satisfying psychometric properties. Elevated risks of poor self-rated health (odds ratios varying from 1.92 to 4.76) are observed in nursing staff characterized by high effort in combination with low reward. Effects are enhanced in those respondents who additionally exhibit a high level of work-related overcommitment. In conclusion, despite methodological limitations, this study contributes to the validation of the ERI questionnaire in Danish language. Furthermore, by documenting associations with poor self-rated health, it supports efforts of theory-guided prevention of work stress in health care professions.

Effort/reward imbalance and sedentary lifestyle: an observational study in a large occupational cohort

OBJECTIVES

To investigate the association between effort/reward imbalance (ERI) at work and sedentary lifestyle.

METHODS

Cross sectional data from the ongoing Finnish Public Sector Study related to 30,433 women and 7718 men aged 17-64 were used (n = 35,918 after exclusion of participants with missing values in covariates). From the responses to a questionnaire, an aggregated mean score for ERI in a work unit was assigned to each participant. The outcome was sedentary lifestyle defined as <2.00 metabolic equivalent task (MET) hours/day. Logistic regression with generalised estimating equations was used as an analysis method to include both individual and work unit level predictors in the models. Adjustments were made for age, marital status, occupational status, job contract, smoking, and heavy drinking.

RESULTS

Twenty five per cent of women and 27% of men had a sedentary lifestyle. High individual level ERI was associated with a higher likelihood of sedentary lifestyle both among women (odds ratio (OR) = 1.08, 95% CI 1.01 to 1.16) and men (OR = 1.17, 95% CI 1.02 to 1.33). These associations were not explained by relevant confounders and they were also independent of work unit level job strain measured as a ratio of job demands and control.

CONCLUSIONS

A mismatch between high occupational effort spent and low reward received in turn seems to be associated with an increased risk of sedentary lifestyle, although this association is relatively weak.

Employee worktime control moderates the effects of job strain and effort-reward imbalance on sickness absence: the 10-town study

STUDY OBJECTIVE

To examine whether the effects of work stress on sickness absence vary by the level of control the employees have over their working times.

DESIGN

Prospective cohort study. A survey of job strain, effort-reward imbalance, and control over daily working hours and days off was carried out in 2000-01. The survey responses were linked with registered data on the number of medically certified (>3 days) sickness absences from one year before the survey until the end of 2003. The mean follow up period was 28.2 (SD 8.1) months. Adjustments were made for demographics and behavioural health risks. Aggregated measures of worktime control according to workplaces were used to control for differences in reactivity and response style.

SETTING

Ten towns in Finland.

PARTICIPANTS

16 139 public sector employees who had no medically certified sickness absences in the year preceding the survey.

MAIN RESULTS

Among the women, individually measured control over daily working hours and days off moderated the association between work stress and sickness absence. The combination of high stress and good worktime control was associated with lower absence rates than a combination of high stress and poor worktime control. This finding was replicated in the analyses using workplace aggregates of worktime control. Among the men, the findings were less consistent and not replicable using aggregated measures of worktime control.

CONCLUSIONS

Good control over working times reduces the adverse effect of work stress on sickness absence especially among female employees.

Exercise and Psychobiological Processes

Interventions that reduce the magnitude of psychobiological responses are justified, at least in part, by the notion that exaggerated responses to stress can have detrimental effects on health. The biological processes underlying the association between stress and coronary heart disease (CHD) are thought to involve haemodynamic, neuroendocrine, inflammatory and haemostatic pathways. One of the many recognised benefits of exercise is in buffering physiological responses to psychosocial stressors, which is thought to be partly mediated by sympatho-inhibitory mechanisms, although other potentially important psychobiological processes such as inflammatory, neuroendocrine and haemostatic pathways have gained little attention. Thus, the present review focuses on the role of exercise in buffering psychobiological processes, particularly in relation to pathways that are directly relevant for reducing CHD risk. There are inconsistencies in the literature regarding the effects of exercise on cardiovascular responses to stressors, which may in part be accounted for by differences in experimental design, characteristics of participants, inadequate assessment of physical fitness, and the confounding effects of acute exercise. However, new emerging evidence suggests that exercise promotes an anti-inflammatory environment and increases tissue sensitivity to glucocorticoids, which may have implications for the effects of exercise on stress-induced inflammatory pathways. Future work should focus on the efficacy of exercise for promoting anti-inflammatory pathways in relation to psychosocial stress.

Effort–reward imbalance, sleep disturbances and fatigue

OBJECTIVES

The objective of this study was to investigate the validity of the effort-reward imbalance (ERI) model in relation to disturbed sleep and fatigue.

METHODS

The study population derived from a subset of the WOLF (WOrk, Lipids, Fibrinogen) cohort study of cardiovascular risk in a working population who replied to the ERI-questionnaire comprising 789 men and 214 women. Cox regression analysis was used to calculate the prevalence ratio (PR) for sleep disorders and fatigue in relation to the components of ERI.

RESULTS

As sleep disturbances and fatigue, based on literature, were defined to be represented by the uppermost quintile, 14% of the men and 23% of the women were affected by sleep disturbances while 14 and 26%, respectively, were affected by fatigue. Higher levels of exposure for the ERI components were associated with increased prevalence of sleep disturbances and fatigue. For men, the strongest association was seen between high overcommitment and fatigue (PR 5.77, 95% confidence interval 2.89-11.5). For women, high effort and sleep disturbances (PR 4.04, CI 1.53-10.7), high effort/reward ratio and sleep disturbances (PR 4.13, CI 1.62-10.5), and between low reward and fatigue (PR 4.36, CI 1.79-10.6) yielded the most obvious associations.

CONCLUSIONS

The present study adds sleep disturbances and fatigue to the list of adverse consequences of effort-reward imbalance.

Social reciprocity and health: new scientific evidence and policy implications

The work contract is based on the norm of social reciprocity where appropriate rewards are provided for efforts and achievements at work. The effort-reward imbalance model of work stress maintains that contractual non-reciprocity in terms of high efforts spent and low rewards received is frequent if people have no alternative choice in the labour market, if they are exposed to heavy competition or if they are intrinsically motivated to engage in excessive work-related commitment. According to the model, long-term exposure to effort-reward imbalance increases the risk of stress-related disorders. An overview of results from prospective epidemiological investigations testing the model is given. Overall, people who experience failed reciprocity at work are twice as likely to suffer from incident cardiovascular disease, depression or alcohol dependence compared to those who are not exposed. Associations are stronger for men than for women. Policy implications of findings for improved worksite health promotion are discussed.

Health-related quality of life measured by the SF12 in working populations: associations with psychosocial work characteristics

This study investigated the contribution of psychosocial work characteristics (decision latitude, job demand, social support at work, and effort-reward imbalance) to health-related quality of life. Data were derived from 2 aircraft manufacturing plants (N=1,855) at the start of a longitudinal study. Regression analysis showed that work characteristics (1st model) explained 19% of the variance in the mental summary score of the Short Form-12 Health Survey. R2 change for work characteristics decreased to 13%, accounting for demographics, socioeconomic status, body mass index, and medical condition (5th model). Including health behavior and personality factors (full model), R2 change for work characteristics remained significant. Psychosocial work characteristics account for relevant proportions in the subjective perception of mental health beyond a wide array of medical variables and personality factors.

Psychosocial stress and cardiovascular diseases

Fifty five years after the first finding relating mood disturbances and cardiovascular diseases, there is still debate on the formation of a cogent conception embracing all the fragments of insight within the various aspects relating psychosocial stress to cardiovascular diseases. The clinical comorbidity is empirically evident, but there are ambiguous research results limiting the value of the proposed pathophysiological mechanisms. Psychosocial stress represents here any event that relates psychological phenomena to the social environment and to the associated pathophysiological changes. Stress denotes the external or environmental factors to which people are exposed, as well as the behavioural or biological reaction to it (response that some authors call "distress"). Cardiovascular diseases will be considered here only when being the consequence of chronic inflammatory disease of arteries (atherosclerosis). The question is: are there pathophysiological reliable mechanisms relating psychosocial stress to the development of cardiovascular diseases?

Associations of childhood circumstances with physical and mental functioning in adulthood

The aim of this study was to examine the associations of parental education and specific childhood circumstances with adult physical and mental functioning. Self-reported data were collected in 2000, 2001 and 2002 among middle-aged women (n=7,171) and men (n=1,799) employed by the City of Helsinki. Functioning was measured by the physical and mental component summaries of the Short-Form 36 Health Survey (SF-36). The lowest quartile of the scores on each component summary was considered to indicate limited functioning. Adult socio-economic circumstances were measured by their own education. Among women parental education was inversely associated with physical functioning. The association remained after adjusting for specific childhood circumstances but disappeared after adjustment for own education. In contrast, parental education was positively associated with mental functioning among women, and the association remained after adjusting for specific childhood circumstances and the own education. Among women childhood adversities such as own chronic disease, parental mental problems, economic difficulties and having been bullied in childhood were associated with both physical and mental functioning. Parental drinking problems were associated with adult mental functioning among women. Among men, chronic disease, economic difficulties and having been bullied in childhood were associated with physical functioning. Parental mental problems, economic difficulties and having being bullied in childhood were also associated with mental functioning among men. These results suggest that the effect of parental education on physical functioning is mediated through one's own education. The association between parental education and mental functioning and the effects of several specific childhood circumstances may suggest a latency effect. Some evidence of cumulative effects of childhood and adulthood circumstances were found among women in physical functioning. Specific childhood circumstances are therefore important determinants of adult functioning. These circumstances provide detailed information on the association of childhood circumstances with adult functioning over and above parental education.

Gender differences in job strain, effort-reward imbalance, and health functioning among Chinese physicians

To examine the association between work stress measured by job strain and effort-reward imbalance (ERI) and health functioning in a sample of hospital-based Chinese physicians, a self-reported survey with a standardized questionnaire was conducted in three hospitals in China, among 256 men and 266 women. It was found that both job strain and ERI were associated with impaired health functioning in men and women, but that ERI indicated a stronger association. Men's job control was significantly higher, and was related to men's physical health; whereas women perceived relatively higher job reward which predicted women's mental health. The findings provide evidence of the adverse effects on health functioning of both job strain and ERI, but ERI appears to have more explanatory power as a model of work stress in this sample of Chinese physicians. In addition, gender differences of work stress with respect to health are present.

Relationship between work stress and body mass index among 45,810 female and male employees

OBJECTIVE

The proportion of overweight and obese people has grown rapidly, and obesity has now been widely recognized as an important public health problem. At the same time, stress has increased in working life. The 2 problems could be connected if work stress promotes unhealthy eating habits and sedentary behavior and thereby contributes to weight gain. This study explored the association between work stress and body mass index (BMI; kg/m2).

METHODS

We used cross-sectional questionnaire data obtained from 45,810 female and male employees participating in the ongoing Finnish Public Sector Cohort Study. We constructed individual-level scores, as well as occupational- and organizational-level aggregated scores for work stress, as indicated by the demand/control model and the effort-reward imbalance model. Linear regression analyses were stratified by sex and socioeconomic status (SES) and adjusted for age, marital status, job contract, smoking, alcohol consumption, physical activity, and negative affectivity.

RESULTS

The results with the aggregated scores showed that lower job control, higher job strain, and higher effort-reward imbalance were associated with a higher BMI. In men, lower job demands were also associated with a higher BMI. These associations were not accounted for by SES, although an additional adjustment for SES attenuated the associations. The results obtained with the individual-level scores were in the same direction, but the relationships were weaker than those obtained with the aggregated scores.

CONCLUSIONS

This study shows a weak association between work stress and BMI.

A prospective study of cumulative job stress in relation to mental health

Background

This study tests associations between psychosocial stress at work measured by the effort-reward imbalance model in a dynamic perspective, and multiple indicators of poor mental health, in a prospective design.

Methods

1986 male and female employees from four Belgian enterprises were followed-up over one year within the framework of the Somstress study. Based on two consecutive measurements, an index of cumulative job stress was constructed and its associations with five indicators of mental health were studied, excluding caseness at entry (for depression, anxiety, somatisation, chronic fatigue and psychotropic drug consumption respectively). Taking into account the longitudinal design, four categories of job stress are defined: 1) employees free from stress at both measures, 2) job stress present at first measure but not at the second one, 3) recent onset of job stress as evidenced by second measure 4) workers exposed to stress at both measures. Multivariate logistic regression with appropriate adjustments was applied.

Results

In bivariate analysis, a clear graded association of cumulative job stress with all five mental health indicators is observed, both in men and women. In multivariate logistic regression analysis, recent onset of stress is strongly associated with poor mental health among men (odds ratios ranging from 1.8 to 4.6), while cumulative stress shows strongest effects on mental health in women (odds ratios ranging from 1.4 to 7.1).

Conclusion

Cumulative experience and recent onset of job stress in terms of high effort spent and low reward received is associated with elevated risk of all five indicators of poor mental health at follow-up in a large cohort of employees.

Relationship between Two Job Stress Models and Coronary Risk Factors among Japanese Part‐Time Female Employees of a Retail Company

The objective of this study was to explore the associations between two major job stress models (job strain and effort-reward imbalance) and coronary heart disease (CHD) risk factors (blood pressure; total, high- (HDL) and low-density lipoprotein (LDL) cholesterol; and triglycerides) in Japanese part-time female employees of a retail company. The study population was either 35 yr old or between 40 and 63 yr old. Data collection was carried out in 2002; a total of 1,401 subjects participated in a medical examination and completed a questionnaire. After adjusting for other covariates (age, relative weight, tobacco use, alcohol consumption, lack of exercise, education, marital status, history of child bearing, medical treatment for disease, and occupation), a significant association was found between the effort-reward imbalance, a "high-cost and low-gain" condition at work, and a high prevalence of low HDL cholesterol (Odds ratio=4.4). A weak but unexpected association was found between job strain and low prevalence of low HDL cholesterol. In explanatory analysis with individual components of the two models, associations were evident between high extrinsic effort and high prevalence of low HDL cholesterol and low prevalence of high triglyceride, high job control and low prevalence of high systolic blood pressure, and high job demands and low prevalence of high systolic and diastolic blood pressure. In this cross-sectional study of Japanese part-time working women, a significant association was found between effort-reward imbalance and unfavorable HDL cholesterol profiles. The findings did not support the hypothesis that job strain is associated with CHD risk factors.

Self-reported economic difficulties and coronary events in men: evidence from the Whitehall II study

BACKGROUND

Numerous studies have demonstrated social inequalities in coronary heart disease using a variety of measures of social position. In this study we examine associations between persistent economic difficulties and serious coronary events. Our aim is to assess whether these associations are (i) explained by other measures of socioeconomic status, and (ii) mediated by psychosocial, behavioural and biological factors.

METHODS

The data come from 5021 middle-aged, white-collar men in the Whitehall II study. Self-reported household financial problems, measured at baseline (1985-88) and Phase 3 (1991-93), were used to construct a five-category score of persistent economic difficulties. Associations between economic difficulties and incident coronary events were determined over an average follow-up of 7 years. Other socioeconomic, psychosocial, behavioural and biological explanatory variables were obtained from the Phase 3 questionnaire and clinical examination.

RESULTS

Age-adjusted Cox regression analyses demonstrated steep gradients in the incidence of coronary events with economic difficulties. The relative hazard between the bottom and the top of the difficulties hierarchy was 2.5 (95% confidence intervals (CI) 1.2-5.2) for fatal and non-fatal myocardial infarction (MI), 2.1 (1.3-3.6) for MI plus definite angina and 2.8 (1.9-4.2) for total coronary events. Adjustment for other markers of socioeconomic position, early life factors, psychosocial work environment characteristics and health-related behaviours had little effect, while adjustment for the biological factors reduced the association between difficulties and coronary events by 16-24%.

CONCLUSION

We have demonstrated an economic difficulties gradient in coronary events in men that is independent of other markers of socioeconomic position and appears to be only partially mediated by well-known risk factors in mid-life.

Do changes in effort-reward imbalance at work contribute to an explanation of the social gradient in angina?

AIMS

To determine whether an increase in effort-reward imbalance over time increases the risk of angina, and whether such increases are associated with lower occupational position.

METHODS

Effort-reward imbalance (ERI) at work was measured in the Whitehall II occupational cohort of London based civil servants at baseline (1985-88) and in 1997. Coronary heart disease was measured in a self-reported health questionnaire by combining the Rose Angina Questionnaire with doctor diagnosed angina in 2001.

RESULTS

Among men, increase in ERI over time was associated with an increased risk of incident angina. Moreover, as increases in ERI were more common among lower grade civil servants, change in imbalance, to some extent, contributed to explaining the social gradient in angina. Among women, increases in imbalance were not associated with risk of angina, and therefore did not contribute to the explanation of the social gradient.

CONCLUSIONS

Reductions in effort-reward imbalance at work may reduce the risk of coronary heart disease among men.

Effort?reward imbalance at work and job dissatisfaction in Chinese healthcare workers: a validation study

OBJECTIVE

The aim of this study was to test the reliability and validity of the Chinese version of the 23-item effort-reward imbalance (ERI) questionnaire and to analyze its association with job dissatisfaction in a sample of Chinese healthcare workers.

METHODS

A self-reported survey was conducted, in university hospitals of China, among 192 male and 608 female healthcare workers.

RESULTS

Appropriate internal consistencies of the three scales: effort, reward, and overcommitment, were obtained. Exploratory factor analysis replicated the theoretically assumed structure of the ERI construct in men and women. Evidence of criterion validity was obtained from cross-correlations of the scales and from their correlations with gender, education and job dissatisfaction. Finally, all three scales were associated with an elevated odds ratio of job dissatisfaction, and the effect was strongest for the ERI ratio as predicted by theory.

CONCLUSION

Based on the results of this study the Chinese version of the ERI questionnaire is considered a reliable and valid instrument for measuring psychosocial stress at work. It is applicable to Chinese working populations and, in particular, to the healthcare sector.

Reviewing the effort–reward imbalance model: drawing up the balance of 45 empirical studies

The present paper provides a review of 45 studies on the Effort-Reward Imbalance (ERI) Model published from 1986 to 2003 (inclusive). In 1986, the ERI Model was introduced by Siegrist et al. (Biological and Psychological Factors in Cardiovascular Disease, Springer, Berlin, 1986, pp. 104-126; Social Science & Medicine 22 (1986) 247). The central tenet of the ERI Model is that an imbalance between (high) efforts and (low) rewards leads to (sustained) strain reactions. Besides efforts and rewards, overcommitment (i.e., a personality characteristic) is a crucial aspect of the model. Essentially, the ERI Model contains three main assumptions, which could be labeled as (1) the extrinsic ERI hypothesis: high efforts in combination with low rewards increase the risk of poor health, (2) the intrinsic overcommitment hypothesis: a high level of overcommitment may increase the risk of poor health, and (3) the interaction hypothesis: employees reporting an extrinsic ERI and a high level of overcommitment have an even higher risk of poor health. The review showed that the extrinsic ERI hypothesis has gained considerable empirical support. Results for overcommitment remain inconsistent and the moderating effect of overcommitment on the relation between ERI and employee health has been scarcely examined. Based on these review results suggestions for future research are proposed.

Social capital and self-rated health in 21 European countries

STUDY OBJECTIVE

The aim of this paper is to explore the association between social capital and self-rated health in different European countries.

METHODS

For the cross sectional, comparative analyses data from 21 European countries were used. 40,856 people aged 15 years and older were personally interviewed in 2003 (European Social Survey). Perceptions of social trust, and membership, participation and voluntary work in civic organisations were used as social capital indicators. Analyses are conducted on an aggregate level (country) and on an individual level.

MAIN RESULTS

Results indicate comparatively low levels of social capital in East and South European countries. Countries with low levels of social capital have a high percentage of residents reporting poor health. Social capital is significantly associated with self-rated health in most of the European countries on the individual level after accounting for gender and age. However, additional adjustment for socio-economic status results in a decrease of the associations between activities in voluntary organisations and health. Further adjustment for social contacts and emotional support results in only minor changes of the associations.

CONCLUSIONS

Analyses reveal strong correlations between social capital and self-rated health in a number of European countries on the aggregate level. Associations on the individual level are weaker in East and South European countries. Moreover, association of self-rated health with perceptions of social trust seems to be more consistent than with activities in voluntary organisations.

Working while ill as a risk factor for serious coronary events: the Whitehall II study

OBJECTIVES

Although sick, some people take no time off work, a phenomenon called "sickness presenteeism." This study examined the association between sickness presenteeism and incidence of serious coronary events.

METHODS

The analyses were based on a cohort of 5071 male British civil servants without previous myocardial infarction. Baseline screening included measurements of health status and coronary risk factors. Absence records were assessed for the 3 years subsequent to baseline screening. The outcome of interest was incident nonfatal myocardial infarction or fatal coronary heart disease (mean length of follow-up=9.1 years).

RESULTS

Seventeen percent of unhealthy employees took no absence during the 3-year follow-up. Their incidence of serious coronary events was twice as high as that of the unhealthy employees with moderate levels of sickness absenteeism (after adjustment for conventional risk factors, hazard ratio 1.97, 95% confidence interval=1.02, 3.83).

CONCLUSIONS

Employers and employees should be aware of the potential harmful effects caused by sickness presenteeism.

A comparison of self-reported sickness absence with absences recorded in employers' registers: evidence from the Whitehall II study

AIM

To compare self-reported sickness absence days in the last 12 months with recorded absences from the employers' registers for the same period.

METHODS

Self-reported sickness absence data over the 12 months preceding baseline (1985-88) were compared with absence records from the employers' registers over the same period for 2406 women and 5589 men, participants in the Whitehall II study of British civil servants. Associations with self-rated health, longstanding illness, minor psychiatric disorder, physical illness, and prevalent coronary heart disease at baseline were determined.

RESULTS

In general, women reported less sickness absence over the last year than was recorded in the employers' registers, while men, with the exception of those in the lower employment grades, reported more. Agreement between self-reported and recorded absence days decreased as the total number of days increased. After adjustment for employment grade and the average number of recorded and self-reported absence days, the total number of self-reported absence days was within two days of the recorded number of days for 63% of women and 67% of men. Associations between annual self-reported sickness absence days and self-rated health, longstanding illness, minor psychiatric disorder, physical illness, and prevalent coronary heart disease were as strong as those for recorded absence days.

CONCLUSION

These findings suggest that agreement between the annual number of self-reported and the annual number of recorded sickness absence days is relatively good in both sexes and that associations with health are equivalent for both measures.

Organisational justice and change in justice as predictors of employee health: the Whitehall II study

OBJECTIVE

Organisational justice has been proposed as a new way to examine the impact of psychosocial work environment on employee health. This article studied the justice of interpersonal treatment by supervisors (the relational component of organisational justice) as a predictor of health.

DESIGN

Prospective cohort study. Phase 1 (1985-88) measured relational justice, job demands, job control, social support at work, effort-reward imbalance, and self rated health. Relational justice was assessed again at phase 2 (1989-90) and self rated health at phase 2 and phase 3 (1991-93).

SETTING

20 civil service departments originally located in London.

PARTICIPANTS

10 308 civil servants (6895 men, 3413 women) aged 35-55.

OUTCOME MEASURE

Self rated health.

MAIN RESULTS

Men exposed to low justice at phase 1 or adverse change in justice between phase 1 and phase 2 were at higher risk of poor health at phase 2 and phase 3. A favourable change in justice was associated with reduced risk. Adjustment for other stress indicators had little effect on results. In women, low justice at phase 1 predicted poor health at phase 2 and phase 3 before but not after adjustment for other stress indicators. Adverse change in justice was associated with worse health prospects irrespective of adjustments.

CONCLUSIONS

The extent to which people are treated with justice in workplaces seems to predict their health independently of established stressors at work. Evidence on reduced health risk after favourable change in organisational justice implies a promising area for health interventions at workplace.

The interrelationship of psychosocial risk factors for coronary artery disease in a working population: do we measure distinct or overlapping psychological concepts?

There is growing evidence that psychosocial factors contribute to the risk of coronary artery disease. Commonly used psychometric scales share several features leading to questions about whether they reflect distinguishable concepts. Study participants were 822 employees of the Augsburg Cohort Study (mean age 40 years, 89% men). The authors analyzed the interrelationship between the following psychosocial measures by applying Pearson correlations and factor analysis to the Hospital Anxiety and Depression Scale (HADS), Type D Personality (DS14), the Maastricht Vital Exhaustion Questionnaire (VE), Social Support (F-SozU), the SF12 Health Survey, and Effort-Reward Imbalance. Although the full correlation matrix revealed low to medium associations supporting the notion that the applied psychometric scales show some conceptual overlap, factor analyses resulted in 13 distinguishable and interpretable factors, considerably reflecting the original psychometric scales. This strengthens the assumption that the psychometric scales used constitute distinct psychological concepts, in particular, depressive symptomatology and negative affectivity versus vital exhaustion.

When It Is Better to Give Than to Receive: Long-Term Health Effects of Perceived Reciprocity in Support Exchange

The authors examined esteem enhancement theory and equity theory in explaining the long-term health status of men (n = 178) and women (n = 575). Baseline characteristics were measured in 1990-1993, intimate reciprocity in 1993, and recorded sickness absences for a 9-year period during 1993-2001. Among women, giving more support than receiving in intimate relationships positively affected subsequent health status, as indicated by fewer sickness absences. Among men, receiving more support than giving predicted fewer absences. These effects remained even after significant covariates were included in the model. Thus, women seem to benefit from giving support in intimate relationships, and men seem to benefit from receiving support in intimate relationships. The findings on women are in line with the esteem enhancement theory. No support was obtained for the equity theory.

Gender differences in the relationship of partner's social class to behavioural risk factors and social support in the Whitehall II study

In most countries health inequality in women appears to be greater when their socio-economic position is measured according to the occupation of male partners or spouses than the women's own occupations. Very few studies show social gradients in men's health according to the occupation of their female partners. This paper aims to explore the reasons for the differences in social inequality in cardiovascular disease between men and women by analysing the associations between own or spouses (or partners) socio-economic position and a set of risk factors for prevalent chronic diseases. Study participants were married or cohabiting London based civil servants included in the Whitehall II study. Socio-economic position of study participants was measured according to civil service grade; socio-economic position of the spouses and partners according to the Registrar General's social class schema. Risk factors were smoking, diet, exercise, alcohol consumption, and measures of social support. In no case was risk factor exposure more affected by the socio-economic position of a female partner than that of a male study participant. Wives' social class membership made no difference at all to the likelihood that male Whitehall participants were smokers, or took little exercise. Female participants' exercise and particularly smoking habit was, in contrast, related to their spouse's social class independently of their own grade of employment. Diet quality was affected equally by the socio-economic position of both male and female partners. Unlike the behavioural risk factors, the degree of social support reported by women participants was in general not strongly negatively affected by their husband or partner being in a less advantaged social class. However, non-employment in the husband or partner was associated with relatively lower levels of positive, and higher negative social support, while men with non-working wives or partners were unaffected. Studying gender differences in health inequality highlights some of the problems in health inequality research more broadly. We are brought face to face with the fact that the development of conceptual models that can be applied consistently to aetiology in both men and women are still at an early stage of development. Closer attention is needed to the different processes behind material power and 'emotional power' within the household when investigating gender differences in health and risk factors.

Employment status, employment conditions, and limiting illness: prospective evidence from the British household panel survey 1991-2001

OBJECTIVES

To assess the relation of the incidence of, and recovery from, limiting illness to employment status, occupational social class, and income over time in an initially healthy sample of working age men and women.

METHODS

Cox proportional hazards models.

RESULTS

There were large differences in the risk of limiting illness according to occupational social class, with men and women in the least favourable employment conditions nearly four times more likely to become ill than those in the most favourable. Unemployment and economic inactivity also had a powerful effect on illness incidence. Limiting illness was not a permanent state for most participants in the study. Employment status was also related to recovery.

CONCLUSIONS

Having secure employment in favourable working conditions greatly reduces the risk of healthy people developing limiting illness. Secure employment increases the likelihood of recovery. These findings have considerable implications for both health inequality and economic policies.

Overcommitment to work is associated with changes in cardiac sympathetic regulation

OBJECTIVE

Work stress is associated with an increased risk for cardiovascular disease (CVD). Exaggerated cardiovascular reactivity to work-related stressors or incomplete recovery after work is a proposed mechanism underlying this increase in risk. This study examined the effects of work stress on 24-hour profiles of the pre-ejection period (PEP), a measure of cardiac sympathetic activity, obtained from ambulatory measurement of the impedance cardiogram.

METHODS

A total of 67 male white-collar workers (age 47.1 +/- 5.2) underwent ambulatory monitoring on 2 workdays and 1 non-workday. Work stress was defined according to Siegrist's model as 1) a combination of high effort and low reward at work (high imbalance) or 2) an exhaustive work-related coping style (high overcommitment).

RESULTS

High overcommitment was associated with shorter absolute PEP levels during all periods on all 3 measurement days, reduced wake-to-sleep PEP differences and reduced PEP variability, as indexed by the SD.

CONCLUSIONS

Overcommitment to work was associated with an increase in basal sympathetic drive and a reduction in the dynamic range of cardiac sympathetic regulation. Both findings are compatible with the hypothesis that overcommitment induces beta-receptor down-regulation.

Acute and chronic psychological stress in coronary disease

PURPOSE OF REVIEW

Coronary artery disease (CAD) is the leading cause of death in the United States and other developed countries. Along with a number of other factors thought to contribute to the high prevalence of CAD in developed societies (longer life expectancy, obesity, sedentary lifestyles), various psychological and social factors appear to promote the development or worsening of heart disease. It is well recognized that stress can be harmful to the cardiovascular system. The combination of the preexisting vulnerability and the major stressor are believed to result in cardiac arrhythmias and/or plaque rupture leading to death.

RECENT FINDINGS

Recently, the epidemiologic evidence of a link between stress and CAD is very convincing, yet the biopsychosocial pathway that would explain how stress can lead to disease is less clear. Different types of psychological stress have been found to be associated with increased cardiovascular events. Evidence regarding the efficacy of psychosocial interventions is also presented.

SUMMARY

It is suggested that, taken as a whole, evidence for a psychological and social impact on CAD morbidity and mortality is convincing.

The measurement of effort-reward imbalance at work: European comparisons

Using comparative data from five countries, this study investigates the psychometric properties of the effort-reward imbalance (ERI) at work model. In this model, chronic work-related stress is identified as non-reciprocity or imbalance between high efforts spent and low rewards received. Health-adverse effects of this imbalance were documented in several prospective and cross-sectional investigations. The internal consistency, discriminant validity and factorial structure of 'effort', 'reward', and 'overcommitment' scales are evaluated, using confirmatory factor analysis. Moreover, content (or external) validity is explored with respect to a measure of self-reported health. Data for the analysis is derived from epidemiologic studies conducted in five European countries: the Somstress Study (Belgium; n = 3796), the GAZEL-Cohort Study (France; n = 10,174), the WOLF-Norrland Study (Sweden; n = 960), the Whitehall II Study (UK; n = 3697) and the Public Transport Employees Study (Germany; n = 316). Internal consistency of the scales was satisfactory in all samples, and the factorial structure of the scales was consistently confirmed (all goodness of fit measures were > 0.92). Moreover, in 12 of 14 analyses, significantly elevated odds ratios of poor health were observed in employees scoring high on the ERI scales. In conclusion, a psychometrically well-justified measure of work-related stress (ERI) grounded in sociological theory is available for comparative socioepidemiologic investigations. In the light of the importance of work for adult health such investigations are crucial in advanced societies within and beyond Europe.