Select Committee on Work and Pensions Written Evidence


Memorandum submitted by University College London (UCL)

SUMMARY

    1.  Stress at work affects short term and long term health.

    2.  A quarter of CHD incidence in the Whitehall II study is attributable to psychosocial working conditions

    3.  Work stress accumulated over the working life is greater in disadvantaged occupations.

    4.  The monitoring of work related stress by the Health and Safety Executive surveys should continue, with additional measures of health.

1.   Psychosocial working conditions and health

  The main conceptual models of psychosocial working conditions used in health research have separated the measurement of potentially stressful working conditions from the health effects of work stress. A widely used work stress model, developed by Karasek and Theorell, conceptualizes work stress in terms of the psychological demands of work and the degree of control over working conditions (Karasek, 1979; Karasek and Theorell, 1990). In Karasek's initial formulation of the model, it was hypothesized that high job demands together with low control over working conditions would be particularly bad for health, and this was labeled job strain. The Karasek model was developed further by the addition of a third dimension relating to degree of social support at work. A supportive working environment is considered to be one where employees receive good support from both colleagues and supervisors and where employees receive clear and consistent information from their supervisors.

  A different model of working conditions, the effort-reward imbalance model, developed by Siegrist, is based on the notion of social reciprocity. This model proposes that a combination of putting high effort into work without adequate reward is detrimental to health (Siegrist, 1996). Effort includes both extrinsic and intrinsic components (for example, work over-commitment) and reward includes esteem or respect, career opportunities including job security and promotion prospects, and financial remuneration.

  The concept of organizational justice is a more recent model of psychosocial working conditions (Elovainio et al, 2002) which may have health consequences. This model concerns fairness of treatment at work and has procedural and relational dimensions. Relational justice refers to the extent to which supervisors consider employees' viewpoints, are able to suppress personal biases, and take steps to deal with their employees in a fair and truthful manner. The procedural component relates to the fairness and consistency of formal decision-making procedures in an organization.

  Although there have been some attempts to obtain objective measures of psychosocial working conditions, it is more usual for psychosocial working conditions to be based on self-report questionnaire measures collected by surveys of employees. Self-report measures have the advantage that they take account of the employees' perception of their work environment which may be an important determinant of health; work characteristics can also vary within the same occupation, for example, depending on the style of the line manager, and self-report measures capture this variation. On the other hand, it has been argued that health status can influence perceptions of work characteristics (reverse causality). In addition, the inclusion of people with negative affectivity characteristics, the tendency to complain in general, may induce spurious associations between self-report measures of both work and health.

  There is a considerable body of evidence from prospective studies showing that all three of these models of work stress are associated with health. In the UK, these associations have been studied in depth in the Whitehall II longitudinal cohort of 10,308 London based civil servants. Predictors of incident coronary heart disease included low control at work and high job demands (Kuper and Marmot, 2003), effort-reward imbalance (see Figure below) and relational justice (Kivimaki et al, 2005). Working conditions including low job control, high job demands, low levels of work social supports, effort-reward imbalance and relational injustice were associated prospectively with psychiatric morbidity (Stansfeld et al, 1997; Ferrie et al, 2006). Low decision latitude and low levels of social supports were associated with increased rates of sickness absence (North et al, 1996) and indicators of both effort-reward imbalance and relational justice were associated with medically certified spells of sickness absence (Head et al, 2007).

  Figure: Effort Reward Imbalance at Work and Coronary Heart Disease

  Adjusted for age, sex and grade

  Source of data for Figure: Kuper et al, 2002.

  The table below summarises the evidence from the Whitehall II study for associations between the different dimensions of psychosocial working conditions and health.

Table Working conditions and health: summary of Whitehall II study findings to date

Work characteristic:  Associated with:

Low decision latitude  —  Obesity

—  Alcohol dependence

—  Poor mental health

—  Poor health functioning

—  Back pain

—  Sickness absence

—  Coronary heart disease

High job demands  —  Obesity

—  Poor mental health

—  Poor health functioning

—  Coronary heart disease

Low social support at work  —  Obesity

—  Poor mental health

—  Poor health functioning

—  Sickness absence

Combination of high effort and low rewards  —  Alcohol dependence

—  Poor mental health

—  Poor health functioning

—  Poor self rated health

—  Sickness absence

—  Diabetes

—  Coronary heart disease

Low relational justice  —  Poor self rated health

—  Poor mental health

—  Sickness absence

—  Coronary heart disease

High job strain (low control and high demands)  —  Weight gain and weight loss

—  Coronary heart disease

Isostrain (low control, high demands, lack of support)  —  Metabolic syndrome

Organisational change  —  Poor mental health

—  Poor self-rated health

—  Increased general symptoms

—  Increased incidence of longstanding illness

—  Adverse sleep patterns

—  Increase in blood pressure

—  Increase in body mass index

Job insecurity  —  Poor mental health

—  Poor self-rated health

—  Increased general symptoms and minor health problems

—  Increased use of health services

—  Sickness absence

—  Sickness presenteeism

—  Increase in blood pressure




  Other studies, mostly carried out in industrialized countries, have also demonstrated associations between psychosocial working conditions and both mental and physical health. A systematic review and meta-analysis of prospective studies reported that job strain, effort-reward imbalance and organizational injustice were all associated with incident coronary heart disease although the magnitude of effects varied between studies (Kivimaki et al, 2006). A meta-analysis of studies of psychosocial work stressors and mental health found consistent evidence that low decision latitude, high job demands, low work social supports, job strain and effort-reward imbalance were risk factors for subsequent mental health problems (Stansfeld and Candy, 2006).

  Although there appears to be some conceptual overlap between the three work stress models, empirical evidence suggests that they each independently influence health (Bosma et al, 1998, Kivimaki et al, 2007).

  Are these observed associations causal or are they a product of methodological problems associated with epidemiological studies of psychosocial factors and health such as reverse causality, reporting bias and residual confounding (Macleod and Davey Smith, 2003) First, this has been studied by investigating plausible biological pathways which may mediate the association between work stress and health. In Whitehall II, there was a dose-response association between iso-strain (a combination of high demands, low control and low support) and the metabolic syndrome, a cluster of physiological risk factors which increase the risk of heart disease and diabetes (Chandola et al, 2006). Body mass index is another potential intermediate factor which has been associated with job strain (Kivimaki et al, 2006) and iso-strain (Brunner et al, 2007). Iso-strain also been linked with biological stress responses associated with the autonomic nervous system (lowered heart rate variability) and dysregulation of the HPA axis (higher morning rise in salivary cortisol) (Chandola 2008).

  Secondly, opportunistic studies of the effects of change in working conditions can provide stronger evidence for a causal link. For example, studies that have taken place in the context of downsizing have shown an association between change in working conditions and subsequent health (Vahtera et al, 1997). In the Whitehall II study, adverse changes in working conditions following civil service restructuring predicted increased rates of sickness absence (Head et al, 2006).

  Intervention studies can provide the best evidence for a causal link between working conditions and health. In addition, intervention studies may offer indications of how best to implement improvements to working conditions. So far, intervention studies to evaluate the effect on health of changing working conditions have tended to be conducted in small samples and findings have not been conclusive (Parkes and Sparkes, 1998). More recently, findings from workplace intervention studies have demonstrated that interventions aimed at improving psychosocial working conditions support led to short term reductions in sickness absence(Bond and Bunce 2001; Michie et al 2004), lowered serum cortisol (Theorell et al, 2001) and reduced mental health problems (Bourbonnais et al, 2006). Further research is needed in this area including evaluation of the development and implementation of work place interventions as well as their effectiveness (Goldenhar et al, 2001; Kristensen 2005).

  Overall the body of evidence on psychosocial working conditions and health has led to recognition by policy makers of work stress as a work place hazard and calls to begin discussions on setting reference values (Benavides et al, 2002) similar to standards already existing in many countries for physical workplace hazards.

REFERENCES

Benavides FG, Benach J, Muntaner C. Psychosocial risk factors at the workplace: is there enough evidence to establish reference values? J Epidemiol Community Health 2002; 56:244-5.

Bosma H, Peter R, Siegrist J, Marmot MG. Two alternative job stress models and the risk of coronary heart disease. Am J Publ Health 1998; 88:68-74.

Bond FW, Bunce D. Job control mediates change in a work reorganization intervention for stress reduction. J Occup Health Psychol 2001;6:290-302.

Bourbonnais R, Brisson C, Vinet A, Vezina M, Abdous B, Gaudet M. Effectiveness of a participative intervention on psychosocial work factors to prevent mental health problems in a hospital setting. Occup Environ Med 2006; 63:335-42.

Brunner EJ, Chandola T, Marmot MG. Prospective effect of job strain on general and central obesity in the Whitehall II Study. Am J Epidemiol 2007 165:828-37.

Chandola T, Brunner E, Marmot M. Chronic stress at work and the metabolic syndrome: prospective study. BMJ 2006; 332:521-525.

Chandola T, Britton A, Brunner E, Hemingway H, Malik M, Kumari M, Badrick E, Kivimaki M and Marmot MG Work stress and coronary heart disease: what are the mechanisms? European Heart Journal 2008 doi:10.1093/eurheartj/ehm584

Elovainio M, Kivimäki M, Vahtera J. Organizational justice: evidence of a new psychosocial predictor of health. Am J Publ Health 2002; 92: 105-108.

Ferrie JE, Head J, Shipley MJ, Vahtera J, Marmot MG, Kivimaki M. Injustice at work and incidence of psychiatric morbidity: the Whitehall II study. Occup Environ Med 2006; 63: 443-450.

Goldenhar LM, LaMontagne AD, Katz T, Heaney C, Landsbergis P. The intervention research process in occupational safety and health: an overview from the National Occupational Research Agenda Intervention Effectiveness Research team. J Occup Environ Med 2001; 43:616-22.

Head J, Kivima­ki M, Martikainen P, Vahtera J, Ferrie JE, Marmot MG. Influence of change in psychosocial work characteristics on sickness absence: the Whitehall II study. J Epidemiol Community Health 2006; 60:55-61.

Head J, Kivima­ki M, Siegrist J, Ferrie JE, Marmot MG, Shipley MJ, Vahtera J. Effort-reward imbalance, organisational justice and sickness absence: findings from the Whitehall II study. Submitted 2007.

Karasek RA. Job demands, job decision latitude and mental strain: implications for job design. Admin Sci Quart 1979; 24:285-308.

Karasek R, Theorell T. Healthy work: stress, productivity, and the reconstruction of working life. New York: Basic Books, 1990.

Kivima­ki M, Ferrie JE, Brunner E, Head J, Shipley MJ, Vahtera J, Marmot MG. Justice at work decreases risk of coronary heart disease among employees: the Whitehall II Study. Arch Intern Med 2005;165:2245-2251.

Kivima­ki M, Head J, Ferrie JE, Shipley MJ, Brunner E, Vahtera J, Marmot MG. Work stress, weight gain and weight loss: evidence for bidirectional effects of job strain on body mass index in the Whitehall II study. International Journal of Obesity 2006; 30: 982-987.

Kivima­ki M, Virtanen M, Elovainio M, Kouvonen A, Va­a­na­nen A, Vahtera J. Work stress in the aetiology of coronary heart disease—a meta-analysis. Scand J Work Environ Health 2006 32:431-442.

Kivima­ki M, Vahtera J, Elovainio M, Virtanen M, Siegrist J. Effort-reward imbalance, procedural injustice and relational injustice as psychosocial predictors of health: Complementary or redundant models? Occup Environ Med Published Online First: 25 January 2007.

Kristensen TS. Intervention studies in occupational epidemiology. Occup Environ Med 2005; 62:205-10.

Kuper H, & Marmot M. Job strain, job demands, decision latitude, and the role of coronary heart disease within the Whitehall II study. J Epidemiol Community Health 2003; 57: 147-153.

Kuper H, Singh-Manoux A, Siegrist J, Marmot M. When reciprocity fails: effort-reward imbalance in relation to coronary heart disease and health functioning within the Whitehall II study. Occup Environ Med 2002; 59: 777-784.

Macleod J, Davey Smith G. Psychosocial factors and public health: a suitable case for treatment? J Epidemiol Community Health 2003; 57:565-70.

Michie S, Wren B, Williams S. Reducing absenteeism in hospital cleaning staff: pilot of a theory based intervention. Occup Environ Med 2004;61:345-9.

North FM, Syme SL, Feeney A, Shipley M, Marmot M. Psychosocial work environment and sickness absence among British civil servants: The Whitehall II Study. Am J Publ Health 1996; 86:332-40.

Parkes KR, Sparkes TJ. Organizational interventions to reduce work stress: are they effective? Report CRR193, HSE Books, 1998. http://www.hse.gov.uk/research/crr_pdf/1998/CRR98193.pdf

Siegrist J. Adverse health effects of high-effort/low reward conditions. J Occup Health Psychol 1996; 1:27-41.

Stansfeld SA, Fuhrer R, Head J, Ferrie J, Shipley M. Work and psychiatric disorder in the Whitehall II study. J Psychosom Res 1997; 43: 73-81.

Stansfeld S, Candy B. Psychosocial work environment and mental health--a meta-analytic review. Scand J Work Environ Health 2006;32:443-62.

Theorell T, Emdad R, Arnetz B, Weingarten AM. Employee effects of an educational program for managers at an insurance company. Psychosom Med 2001;63:724-33.

Vahtera J, Kivima­ki M, Pentti J. Effect of organisational downsizing on health of employees. Lancet 1997; 350:1124-8.

2.   The burden of disease among a working population attributable to work stress

  (Unpublished work)

  Head J, Kivima­ki M, Stansfeld SA, Brunner E, Ferrie JE, Marmot MG

Abstract

Background

  Although work is good for health, within the working population there is variation in incidence of depression and coronary heart disease according to levels of psychosocial working conditions. The aim of this study is to estimate the potential avoidable proportion of psychiatric morbidity and coronary heart disease (CHD) associated with psychosocial work conditions.

Methods

  The Whitehall II prospective cohort study of British civil servants, 10308 men and women, was established between 1985 and 1988. Participants were classified into three groups (low, intermediate and high) on the basis of their scores on each of five psychosocial work exposures measured at baseline: job control, job demands, work social supports, relational justice and effort-reward imbalance. Excess risk of psychiatric disorder (measured by the 30 item General Health Questionnaire) and coronary heart disease (CHD death, first non-fatal myocardial infarction or definite angina) associated with psychosocial work stress was estimated using the population attributable risk (PAR) method.

Findings

  Estimates of PAR showed that 34% (95% CI 24%-43%) of cases of minor psychiatric morbidity among this working population were potentially attributable to adverse psychosocial working conditions. Just over a quarter of CHD incidence was attributable to these five psychosocial work conditions (PAR 29%, 95%CI 9%-45%).

Interpretation

  Adverse levels of job control, job demands, work social supports, relational injustice and effort reward imbalance account for a substantial proportion of illness in this working population. Interventions to improve these aspects of working conditions have the potential to improve health.

3.   Psychosocial working conditions and social inequalities in health

  Large and persistent social class differences in health have been observed in the UK, despite the existence of the National Health Service for more than 50 years providing universal access to health care. Earlier explanations for this health gap suggested these inequalities originated in the material circumstances such as poverty and deprivation, as well as behavioural lifestyles such as smoking. However, the first Whitehall study, conducted among British civil servants, made clear that inequalities in health were not limited to the health consequences of poverty or conventional risk factors for ill health. Psychosocial factors such as work stress were hypothesized to fill in the unexplained part of the social gradient in mortality, mental well being and sickness absence.

  The nature of working conditions has changed considerably in most industrial countries. A substantial part of the economically active population are now more likely than ever to work on temporary contracts, for a fixed term and in insecure employment. These adverse working conditions tend to be more prevalent in lower socioeconomic occupations and disadvantaged occupational classes- the lower the socioeconomic position, the higher the risk of exposure to adverse and stressful working conditions.(Siegrist 2002)

  However, not all dimensions of stressful working conditions are more prevalent in lower SES occupations. Higher job demands, as characterised by the job strain model, tend to be more prevalent in higher SES occupations.(Bosma et al, 1997) In addition, workers in higher SES jobs may be exposed to greater work effort, a characteristic of the effort reward imbalance model.(Siegris et al, 2004) On the other hand, lower job control (Bosma et al,1997; Godin and Kittel, 2004) and fewer rewards (Siegrist et al, 2004) tend to characterise lower SES occupations. Furthermore, when the social gradient in the overall measure of stressful working conditions (job strain and effort-reward imbalance) is analysed, rather than specific components, work stress tends to be reported primarily by those in lower SES occupations (Kouvonen et al, 2006; Tsutsumi et al, 2001). Even when greater effort-reward imbalance is reported by higher SES workers earlier on in their career (Kuper et al, 2002), lower SES workers tend to report a greater deterioration in their working conditions over their career lifetime (Chandola et al, 2005).

  There is some debate about whether stressful working conditions account for some of the social gradient in health. Low control, (Bosma et al, 1997; Kunz Ebrecht et al, 2004) skill discretion (Andersen et al, 2004), job strain (Chandola et al, 2006), effort reward imbalance (Chandola et al, 2005) have been found to account for some of the social gradient in different measures of health. In addition, the effect of effort reward imbalance may be greater in lower SES occupations (Siegrist, 2004). On the other hand, not all dimensions of adverse psychosocial working conditions contribute to explaining social inequalities in coronary heart disease (Suadicani et al, 1993).

  If stressful working conditions mediate the effect of SES on health, we would expect to find strong evidence of the association between low SES and stress related biomarkers. There is some conflicting evidence from the scientific literature. Some report that lower SES is not associated with biological markers for stress (Dowd and Goldman, 2006), while others find that lower SES is associate with higher biological stress responses in terms of a greater cortisol awakening response (Wright and Steptoe, 2005).

  In summary, adverse working conditions tend to cluster in lower SES occupations. Most of the studies show some dimensions of stressful working conditions mediate or moderate the effect of social inequalities in health, although a minority of studies questions this link.

REFERENCE LIST

Andersen I, Burr H, Kristensen TS et al. Do factors in the psychosocial work environment mediate the effect of socioeconomic position on the risk of myocardial infarction? Study from the Copenhagen Centre for Prospective Population Studies. Occup Environ Med 2004;61:886-92.

Bosma H, Marmot MG, Hemingway H, Nicholson AC, Brunner E, Stansfeld SA. Low job control and risk of coronary heart disease in Whitehall II (prospective cohort) study. BMJ 1997;314:558-65.

Chandola T, Siegrist J, Marmot M. Do changes in effort-reward imbalance at work contribute to an explanation of the social gradient in angina? Occup Environ Med 2005;62:223-30.

Chandola T, Brunner E, Marmot M. Chronic stress at work and the metabolic syndrome: prospective study. BMJ 2006;332:521-25.

Dowd JB, Goldman N. Do biomarkers of stress mediate the relation between socioeconomic status and health? J Epidemiol Community Health 2006;60:633-39.

Godin I, Kittel F. Differential economic stability and psychosocial stress at work: associations with psychosomatic complaints and absenteeism. Soc Sci Med 2004;58:1543-53.

Kouvonen A, Kivimaki M, Virtanen M et al. Effort-reward imbalance at work and the co-occurrence of lifestyle risk factors: cross-sectional survey in a sample of 36,127 public sector employees. BMC Public Health 2006;6:24.

Kunz-Ebrecht SR, Kirschbaum C, Steptoe A. Work stress, socioeconomic status and neuroendocrine activation over the working day. Soc Sci Med 2004;58:1523-30.

Kuper H, Singh-Manoux A, Siegrist J, Marmot M. When reciprocity fails: effort-reward imbalance in relation to coronary heart disease and health functioning within the Whitehall II study. Occup Environ Med 2002;59:777-84.

Siegrist J. Reducing social inequalities in health: work-related strategies. Scand J Public Health Suppl 2002;59:49-53.

Siegrist J, Starke D, Chandola T et al. The measurement of effort-reward imbalance at work: European comparisons. Soc Sci Med 2004;58:1483-99.

Siegrist J. Social Variations in Health Expectancy in Europe: An ESF Scientific Programme. Dusseldorf, http://www.uni-duesseldorf.de/health/FinalReport.pdf: 2004 Department of Medical Sociology, University of Dusseldorf.

Suadicani P, Hein HO, Gyntelberg F. Are social inequalities as associated with the risk of ischaemic heart disease a result of psychosocial working conditions? Atherosclerosis 1993;101:165-75.

Tsutsumi A, Kayaba K, Tsutsumi K, Igarashi M. Association between job strain and prevalence of hypertension: a cross sectional analysis in a Japanese working population with a wide range of occupations: the Jichi Medical School cohort study. Occup Environ Med 2001;58:367-73.

Wright CE, Steptoe A. Subjective socioeconomic position, gender and cortisol responses to waking in an elderly population. Psychoneuroendocrinology 2005;30:582-90.

4.   Psychosocial working conditions and political responses

  The Health and Safety Commission (responsible for Health and Safety at Work in Britain) identified work stress as one of its main priorities under the Occupational Health Strategy for Britain 2000: Revitalising Health and Safety which set out to achieve, by the year 2010: a 30% reduction in the incidence of working days lost through work-related illness and injury; a 20% reduction in the incidence of people suffering from work related ill-health; and a 10% reduction in the rate of work-related fatal and major injuries.

  In 2004 the UK Health and Safety Executive (the authority responsible for developing and implementing policies in support of the Health and Safety Commission) introduced management standards for work-related stress. These standards cover six work stressors: demands, control, support, relationships, role and change. A risk assessment tool was released at the same time as the management standards which consists of 35 items on working conditions covering the six work stressors. This risk assessment tool is freely available on the Health and Safety Executive website (www.hse.gov.uk/stress) together with supporting analytical software. The HSE management standards adopted a population based approach to tackling workplace stress aimed at moving organizational levels to more desirable levels rather than identifying individual employees with high levels of stress (Mackay et al, 2004). Rather than setting reference values for acceptable levels of psychosocial working conditions that all employers should meet, the standards set aspirational targets that organizations can work towards:

    "Your ultimate aim is to be in the top 20% of organisations in tackling work-related stress as currently assessed by HSE (in 2004). If an organisation is currently not achieving the benchmark figure, then an interim figure is also given as a stepping stone towards improvement. That is, HSE supports continuous improvement in stress management."

  HSE website guidance for employers

  The management standards are not in themselves a new law but following the management standards approach can help employers meet their legal duty under the Management of Health and Safety at Work Regulations 1999 to assess the risk of stress-related ill health activities arising from work.

  As part of a three year implementation programme, in 2006-07 the Health and Safety Executive have been actively rolling out management standards to 1,000 work places by providing support for both conducting risk assessments and for making changes based on results of risk assessments. Recognising that work stress is a significant contributor to sickness absence, the UK Government has recently introduced a strategy for the health and well-being of people of working age "Work, health and well-being- Caring for our Future" which includes a recommendation to apply the HSE management standards approach across the public sector as part of a drive to reduce levels of sickness absence. In addition, UK organizations including the HSE and the TUC (representing trade unions), have drawn up a European Social Partner agreement on work-related stress (http://www.dti.gov.uk/files/file25664.pdf).

  How is the management standards approach being evaluated? So far, evaluations in work places adopting the management standards approach have mostly been qualitative and good practice case studies are being made available on the HSE website (www.hse.gov.uk/stress). A national monitoring survey was conducted in Spring 2004, six months before the introduction of the management standards, to provide a baseline for future monitoring of trends in psychosocial working conditions. The intention is that this survey should be repeated annually and, at the time of writing, reports from the 2004 and 2005 surveys have been published. However, health is not measured in these surveys making it hard to estimate changes in psychosocial working conditions and health.

REFERENCES

Mackay CJ, Cousins R, Kelly, PJ, Lee S, McCaig, RH. (2004) "Management Standards" and work-related stress in the UK: Policy background and science. Work and Stress, 18(2),91-112.

UCL

January 2008



 
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