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Public Lecture at FIOCRUZ Rio de Janeiro 29 November 2011 Work stress and health in the era of economic globalisation Johannes Siegrist, PhD Professor and Director Department of Medical Sociology University of Duesseldorf, Germany. Importance of work for health. Work …
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Public Lecture at FIOCRUZ Rio de Janeiro 29 November 2011 Work stress and health in the era of economic globalisation Johannes Siegrist, PhD Professor and Director Department of Medical Sociology University of Duesseldorf, Germany
Importance of work for health Work … • provides a source of regular income and related opportunities • provides a source of personal growth and training opportunities • provides social identity, social status and related rewards • enables access to social networks beyond primary groups • influences a person’s self efficacy and self esteem • exposes a person to differential quality of work environment
Quality of work and health Traditional focus: workplace • Chemical & physical hazards and specific ergonomic conditions reduce employees’ health and increase injury risk Domain of occupational medicine and safety Modern focus: work organization and employment conditions • Specific features enhance or reduce employees’ health through psychosocial stress-related mechanisms Domain of ‚new‘ occupational health research and policy
Significant changes in the nature of work and labour market • fewer jobs defined by physical demands, more by mental and emotional demands • increase of service sector, computer-based job profiles • increase in flexible work arrangements, part-time work, de-standardized work arrangements • growing job instability / discontinuity; precarious work and unemployment • Segmentation of labour market; social gradient of quality of work and employment
Economic globalisation Expansion of free market principles and technological innovations from high income to middle and low income countries • International organizations (WB, IMF, WTO) • Transnational corporations • Transnational capital flow • Globalized labor market • Neo-liberal policies (deregulation, disinvestment in welfare states, reduced impact of trade unions)
Effects of economic globalisation: Labour market consequences in developed countries Increased pressure of rationalisation (mainly due to wage competition) Downsizing, Merging, Outsourcing Work Job Low wage / intensification insecurity salary
Work and health: What is known? Long-term unemployment Physical/chemical hazards Precarious work, job instability Overtime/shift work Stressful work in more privileged jobs
Long-term unemployment and mortality (10 yrs. follow up 1990-2000) Hazard Ratio Source: M. Kivimäki et al. (2003), Am J Epidemiol, 158:663-668.
Key messages • Work stress is a risk factor of several major chronic disorders and contributes to social inequalities in health. • Scientific evidence is particularly strong in high income countries. • With economic globalisation this evidence extends to rapidly developing countries. • Evidence-based policy interventions at the organizational, national and international level are needed to reduce stressful work and employment and related health inequalities.
Work stress and health: evidence from high income countries Definition of work stress A working person‘s reaction to a threatening demand (stressor) that taxes or exceeds her/his capacity of successful response. • Negative emotions, e.g. anxiety, frustration, helplessness • Physiological stress responses (hormones, ANS) Risk of stress-related disorders: Function of duration and intensity of stressor
Main diseases related to work stress Mental illness Cardiovascular diseases Musculoskeletal disorders Reproductive hazards
Mean growth of atherosclerotic plaques (mm2) Social group Beta-blocking agent (only unstable group) dominant subordinate Threat to control and social reward by experimental manipulation of social status in male macaques: effects on coronary atherosclerosis Source: J.R. Kaplan et al. (1994), Am Heart J, 128: 1316.
Work stress: How to identify toxic components within complex environments? negative emotions stress-related disorders stress responses
Why do we need theoretical models? A theoretical model... • reduces the complex reality at work to critical (‚toxic‘) components • allows forgeneralisationbeyond single observations • provides anexplanationof associations between work and health • serves as a guide for health-promotinginterventionsat work
Three theoretical models of the psychosocial work environment • Demand-control model (R. Karasek, 1979; R. Karasek & T. Theorell, 1990) • Effort-reward imbalance model(J. Siegrist, 1996; J. Siegrist et al., 2004) • Organizational justice model(J. Greenberg, 1990; M. Elovainio et al., 2002) • Features of job tasks • Features of work contracts • Features of organizational procedures
Quantitative demands low high Scope of decision/control low distress high active high distress low passive The demand-control model(R. Karasek 1979; R. Karasek & T. Theorell 1990)
The model of effort-reward imbalance (J. Siegrist 1996) • labour income • career mobility / job security • esteem, respect Extrinsic components demands / obligations reward effort motivation (‘overcommitment‘) motivation (‘overcommitment‘) Intrinsic component
Why do people continue to work in ‚high cost – low gain‘ conditions? • DependencyThe working person hasno alternative choicein the labour market: accepting contractual unfairness is preferred to job loss. • Strategic choiceThe working person accepts imbalance in order toimprove future career development(anticipatory investment). • OvercommitmentThe working person exhibits amotivational patternof excessive work-related commitment where investments often exceed gains. Overcommitment is either due topersonalityor due topressure at work.
Conceptual Differences between the Demand-Control (DC) and the Effort-Reward Imbalance Model (ERI) DC • Focus on job task: high demands and low control • Threat to personal control / low self efficacy(cognitive appraisal) • Democracy, participation ERI • Focus on work contract: non-reciprocity of efforts and rewards • Threat to social rewards / low self esteem (affective information processing) • Distributive justice, contractual fairness
The Organizational Justice Model • Procedural justicePerceptions of consistent, accurate, unbiased and ethical rules of procedures • Relational justicePerceptions of polite, fair interactions from supervisors • Distributive justicePerceptions of appropriate distribution of job tasks and gains among employees So far, procedural and relational justice only were measured with relevance to health and performance.
Measurement of the models • Both models are measured by a standardized self-assessed questionnaire which can be applied to a variety of different occupational groups: • Job Content Questionnaire (JCQ) (R. A. Karasek)www.workhealth.org • Effort-Reward Imbalance Questionnaire (ERI) (J. Siegrist)www.uni-duesseldorf.de/MedicalSociology • Both questionnaires fulfill criteria of psychometric quality (factorial structure of scales, reliability, discriminant and predictive validity etc.). • Both questionnaires are available in a number of languages and have been used in comparative international studies.
Measurement of effort-reward imbalance at work • Scale‚effort‘(6 Likert-scaled items) = perceived demands (Cronbach‘s α = .72) • Scale‚reward‘(11 Likert-scaled items) = experienced or promised gratifications (Cronbach‘s α = .83) • 3 subscales: (a) salary and promotion, (b) esteem, (c) job security • ‚ratio effort/reward‘= sum score ‚effort‘ / (sum score ‚reward‘ 6/11) • Scale‚overcommitment‘(6 Likert-scaled items) = pattern of coping with demands and rewards (Cronbach‘s α = .76) For detailed information see:http://www.uni-duesseldorf.de/MedicalSociology/
Psychometrically validated scales of the ERI questionnaire • Languages: • German, English, Swedish, Dutch, French, Italian, Spanish, Portuguese, Jaapanese, Chinese/Taiwanese, Korean, Thai • The Brazilian version: • D. Chor et al. (2008) Cad Saude Publica 24: 219-224 • R. Härter Griep et al. (2009) Int Arch Occup Environ Health 82: 1163-1172
Public health relevance of stress-related disorders „By the year 2020 depression and coronary heart disease will be the leading causes of premature death and of life years defined by disability (DALY‘s) worldwide.“ (Murray and Lopez 1996) Focus on coronary heart disease and depression
What is the scientific evidence of a direct association of work stress with disease? Methodological approaches: epidemiological and experimental Epidemiological research: • prospective observational cohort study (gold standard) • cross-sectional and case-control-study (weaker evidence) • intervention study (limited options) Experimental research: • laboratory experiments (limited ecological validity) • ambulatory monitoring at work (limited control)
Mortality (rate ratio) 40-64 years 64-69 years 70-89 years Mortality (rate ratio; 25 years) according to occupational position: the Whitehall-Study N=18.000) Source: M. Marmot & M.J. Shipley (1996), Brit Med J, 313: 1177.
Effort-reward imbalance model:% imbalance between effort and reward Demand-control model:% job strain (observer judgement) high, middle, low occupational status Social inequality of work stress in the Whitehall II-Study Source: Bosma et al. (1998), Am J Publ Health, 88: 70.
* * adjusted for age, sex, length of follow-up + alternative work stress model + grade, coronary risk factors, negative affect * p < .05 Work stress (effort reward imbalance/job control) and CHD incidence, men and women: Whitehall II-Study Source: H. Bosma et al. (1998), Amer J Publ Health, 88: 68-74
Overtime work increases the risk of coronary heart disease: Whitehall II study Mean daily overtime in hours (h) at baseline (N=6014 civil servants) followed over 11 years*; * Hazard ratios adjusted for 21 risk factors Source: Virtanen M et al. (2010) Eur Heart J: doi10.1093/eurheartj/ehq124
Workplace demands, economic reward, and 4-year progression of carotid atherosclerosis (plaque height) in 940 Finnish men 4-year increase In plaque height (mm) Work demands Economic rewards p = .04 (adj.) Source: J. Lynch et al. (1997), Circulation, 96: 302
Mean systolic blood pressure (mmHg) in men over a working day according to overcommitment and occupational grade (N=105) Source: A. Steptoe et al. (2004), Psychosomatic Medicine, 66: 323-329.
Inflammatory response (CRP) during experimentally induced mental stress according to level of effort-reward imbalance (N=92) 0.12 0.10 0.08 0.06 0.04 0.02 0.00 p < .05 low medium high effort-reward imbalance CRP change# (μg/ml) as function of effort-reward imbalance # adjusted for age, BMI, baseline levels Source: M. Hamer et al. (2006), Psychosom Med, 68: 408-413.
* men women * * Effort-reward imbalance and affective disorder (GHQ): Whitehall II-Study (odds ratios#; N=6110, follow-up: 5.3 years) # adjusted for age, employment grade, baseline GHQ score Source: S.A. Stansfeld et al. (1999), Occup Environ Med, 56: 302-7.
Cumulative work stress and reduced mental health (SCL-90): Belgian Somstress-Study (N=920, 1 yr.) % t1 no -t2 no t1 yes -t2 no t1 no -t2 yes t1 yes -t2 yes effort-reward imbalance Source: I. Godin et al. (2005), BMC Public Health, 5: 67.
Work stress (ERI), occupational position and depression (HNR Study; baseline; N=1811 men and women aged 45-65) * Risk of depression Synergy index: 1.99 (1.02-3.85) Odds ratio * Source: N. Wege, N. Dragano, J. Siegrist (2008) JECH 62: 338-341
Morning cortisol after dexametason-test in teachers with or without work stress (N=135) Source: Bellingrath S et al (2008) Biol Psychol 78: 104-113
Work stress (ERI) and natural killer cells in 347 Japanese employees Source: Nakata A et al (2011) Effort-reward imbalance, overcommitment, and cellular immune measures among white-collar employees. Biol Psychol [in press]
The social gradient of work stress in the European workforce (age 50-65): SHARE-study Source: Wahrendorf M et al. 2011 (unpublished results based on SHARE release 2.3.0)
80% 70% 60% 50% desire for early retirement 40% 30% 20% 10% ES FR IT AT GR DE SE DK CH NL low work stress medium work stress high work stress Work stress (effort-reward imbalance) and the desire for early retirement (SHARE Study; N=6,524) Source: Adapted from Siegrist et al. (2006). EJPH.
Increasing relevance of work stress in rapidly developing countries due to globalisation • First studies applying the ERI-model in China, Taiwan, South Korea and Brazil • Reduced health functioning in Chinese physicians (Li et al. 2006) • Elevated risk of menstrual disorders in Chinese railway workers (Zhou et al. 2010) • Elevated risk of depression in Taiwanese engineers (Chen et al. 2010) • Reduced health functioning in blue collars in South Korea (Eum et al. 2008)
Psychosocial stress at work in Chinese male coronary patients vs. healthy controls (N=388) Adjusted for age, and sex; Additionally adjusted for hypertension, diabetes mellitus, smoking, BMI, CHD family history, educational level, and marital status; *p<0.05; **p<0.01; ***p<0.001 Source: Xu W. et al (2009) J Occup Health 51: 107-113
Psychosocial stress and hypertension among working women in Beijing (N=421 ♀; 38,88,1 y.) Multivariate prevalence odds ratio of hypertension Low reward 3.09 (1.21 - 7.92) Low job variety 3.05 (1.49 - 6.27) Conflict between workand family 3.79 (1.19 - 3.95) Smoking 2.17 (1.19 - 3.90) BMI ≥ 25 7.29 (3.71 - 14.37) Source: L.Y. Xu et al. (2000), Int J Behav Med, 7, S1: 10.
School stress (ERI-S) and poor self-rated health in Chinese students N=1004 boys and girls; mean age: 15.9 +/-2.5: OR adj. for age, grade, health behaviours, family wealth Source: J. Li et al. (2010) J Epidemiol 20: 111-118.
Work stress and poor self-rated health among Brazilian nurses in public hospitals (n=1307) • Odds ratios* of poor self-rated health among nurses in public hospitals • * adj. For age, education, work contract, nr. of jobs, physical activity, smoking, alcohol Source: R. Härter Griep et al. (2011) Rev Saúde Publica 45:1-8.
Summary: Main features of health promoting work • Challenging task profile providing autonomy, control and opportunities of personal development • Appropriate material and non-material rewards in return to accomplished achievements • Trusting, fair and supportive relationships at work • Meaningful and secure employment
Evidence-based policy interventions at different levels Legislation, Regulation, Social movements Economic, political context Organizational context Job insecurity, Downsizing Precarious work New systems of work organization Employer initiated new systems of work organization, Collective bargaining Job characteristics Low job control / reward High job demands / effort Employer initiated job redesign, Labor-management committees, Action research Stress response Physiological effects (e.g., BP ) Psychological effects (e.g., burnout) Health behaviors Health promotion, Stress management Treatment, Rehabilitation, Return-to-Work programs Illness
Structural intervention at the level of single organisations: demand-control model • Job enrichment • Job enlargement (decision, control, responsibility) • Tasks with enhanced skill utilization / active learning • Increase of participatory activities • Strengthening social support at work • Extensive job training, requalification • Reduced status differences, flat hierarchies
Structural intervention at the level of single organisations: effort-reward imbalance model • Compensatory wage differentials • Models of gain-sharing • Flexible time arrangements • Incentives for esteem / recognition • Enhanced leadership skills (managers) • Promotion prospects according to achievements • Extensive job training / requalification • Job security
Work stress and health problems after structural intervention* Variable Demand Control Supervisor support Coworker support ERI Psychol. distress Work-rel. burnout Means at t1 adj. for t0 experimental - control hospital p 12.08 68.59 10.82 12.49 1.10 21.17 46.66 12.68 68.06 10.42 12.26 1.15 22.43 49.03 .015 .382 .028 .056 .002 .205 .034 *12 month-follow-up, two Canadian hospitals, N=302 (intervention) vs. 311 (control hospital) (ANCOVA, adj. for baseline values) Source: R. Bourbonnais et al. (2006), Occup Environ Med, 63: 335.