Presentation on theme: "The Changing Nature of Work – And its Implications for Cardiovascular Disease Fourth International Conference on Work Environment and Cardiovascular Diseases."— Presentation transcript:
The Changing Nature of Work – And its Implications for Cardiovascular Disease Fourth International Conference on Work Environment and Cardiovascular Diseases Tage S. Kristensen NIOH, Copenhagen Southern California March 9 – 11, 2005
Work and CVD The new challenges The new fatigue Family and private life Problems with methods and design? Conclusions
General model for the relationship between work environment and cardiovascular diseases The significance of work: 1 + 3 CVD risk factors: diet obesity, blood pressure, smoking etc. CARDIO- VASCULAR DISEASES. WORK ENVIRON- MENT 1 2 3
Causal network for CVD Work envi- ronment Social isolation Unemploy- ment Noise Physical activity Tobacco Diet Alcohol Fitness Obesity Type A Stress Cholesterol Blood pressure Fibrinogen Glucose Athero- sclerosis Thrombosis Arrhythmia ECG- changes SES & Occupation …. Upstream Downstream CVD Social & Environmental Factors Behavior Individual Characteristics PhysiologyPrecursors
The cardiovascular tradition from Framingham and onwards Cholesterol Fibrinogen Triglycerides Glucose Blood pressure Heart rate Obesity Risk factors are individual Smoking Physical inactivity Type A Salt intake Diet Alcohol Physiological: Behavioral:
The occupational medicine tradition from Ramazzini and onwards Physical Chemical Psychosocial Ergonomic Biological Risk factors are environmental
Etiological fractions of work environment for cardiovascular diseases in Denmark Olsen & Kristensen. J Epidemiol Community Health 1991;45:4-10. DK-2004-016 Proportion of CVD Risk factorMenWomen “Sedentary” work42% Job strain6%14% Shift & night work7% Noise1% Chemical exposures0-1%0% Passive smoking2% All factors51%55% All factors except sedentary work16%22%
The significance of work environment for mortality Estimates of etiologic fractions in Finland MenWomen Cardiovascular, total14%7% IHD19%9% Cerebrovascular12%8% Cancer, total13%2% Mental disorders 7%2% Respiratory diseases 7%1% Accidents4%0% Total10%2% Nurminen & Karjalainen. Scand J Work Environ Health 2001;27:161-213.
The significance of work environment for hospitalisations Estimates of etiologic fractions in Denmark MenWomen Circulatory16%18% Cancer 8% 3% Nervous system17%12% Respiratory16%12% Accidents17% 6% Musculoskeletal21%19% Total15%11% Tüchsen et al. Sci Total Environ 2004;328:287-294.
Etiologic fractions of psychosocial factors for acute myocardial infarctions: The INTERHEART STUDY 11,119 cases and 13,648 controls from 52 countries Etiologic fractions* Work stress 9% Home stress 8% Financial stress11% Life events10% Locus of control16% Depressive mood 9% All psychosocial factors33% Rosengren et al. www.thelancet.com Sept. 3,2004:1-10www.thelancet.com * Adjusted for cardiovascular risk factors
Conclusion CVD is one of the most important causes of disease, disability, and mortality in the world. The etiologic fraction of the work environment is higher than for all other major diseases. CVD is the most common and most serious of all work-related diseases. In spite of this, CVD plays a minor role in occuptional medicine, and work plays a minor role in cardiology and cardiovascular epidemiology.
Blood pressure and pulse among Norwegian metal workers Erikssen et al. Tidsskr Nor Laegeforen. 1990;110:2873-7. BP (mm Hg) (N = approx. 180) Threat of closure Pulse SBP Pulse DBP 129 130 135 142 145 143 63 69 70 84 85 86 90 94 96 91
Hospital admissions for CVD in a group of unemployed men compared with a control group Iversen et al. BMJ 1989;299:1073-6. 0.80 1.04 1.60 Before factory closure (2 years) During factory closure (3 years) After factory closure (3 years) 0 1.8 1.6 1.4 1.2 1 0.8 0.6 0.4 0.2
New cases of ischemia* Threats to employment security among white-collar workers in Whitehall A five-year follow-up study N=8354 1.0 1.40 1.60 1.45 Control departments RR Men Women Total Department under privatization Ferrie et al. AJPH 1998;88:1030-1036. *ECG or angina
Organisational downsizing and mortality A 7.5 years’ follow-up study of 22.430 public employees who kept their jobs. 1.0 1.5 1.0 1.2 2.0 1.2 RR* None Minor Major None Minor Major Extent of downsizing 2.0 1.0 0 Vahtera et al. BMJ 2004;328:555-558. *Controlled for age, gender, SES, occupation CVD Other deaths
A simple model Job insecurity, downsizing, outsourcing, privatization Loss of control, loss of social support, loss of meaning, loss of predictability, loss of rewards Stress, uncertainty, hopelessness, low self esteem
The development of four different symptoms in the adult Swedish population 1986 - 2001 Percent Fatigue Back trouble Sleep trouble Distress Gustafsson & Lundberg, eds. Arbetsliv och hälsa, 2004.
Work-related burnout Work-related burnout and sleeping problems two years later Results from the PUMA baseline and 2 years’ follow-up N = 1014; Data from NIOH, Denmark 25.1 32.6 34.4 44.6 Low High Quartiles Karolinska sleep questionnaire (scale)
Burnout as predictor of ischaemic heart diseas A 4.2 years’ follow-up study of 3,877 Dutch male employees from Rotterdam ”Have you ever been burned out?”No74% Yes26% Burnout * Controlled for age, BP, smoking, cholesterol. 59 cases. Appels & Schouten. Behav Med 1991;Summer:53-59 1 2.13 No Yes 2 1 0 RR* for IHD *
Exhaustion and CHD A 9.5 years’ follow-up study of 3,365 Dutch men. 26 30 45 50 40 30 20 10 0 NoneMedium High Degree of exhaustion by the end of the working day. Cases per 1000 Appels & Otten. Br J Clin Psychol 1992;31:351-356
Vital exhaustion, IHD and death 6 years of follow-up of 9,563 adults from Copenhagen * Adjusted for 13 biological, behavioural and social factors Prescott et al. Int J Epidemiol 2003;32:990-7 Vital exhaustion IHD Mortality 1 1.1 1.6 1.8 1.2 2.2 1.6 3 2 1 01-45-910+ 0 RR*
Sleep quality and myocardial infarction 3 years of follow-up of 416 middle-aged German blue-collar workers Siegrist. J Chron Dis 1987;40:571-578. RR 1.0 3.8 1.0 2.6 No Yes Wake up early Difficulty staying asleep
Psychological risk factors for CHD among homemakers from Framingham *Adjusted for CVD risk factors. Eaker et al. Am J Epidemiol 1992;135:854-864. A 20-year follow-up study of 362 women 1.0 7.8 RR * 6.2 3.9 1.0 8 7 6 5 4 3 2 1 0 - + - + - + Tension Symptoms of anxiety Trouble falling asleep
Sleep and risk of IHD A study of 71,617 American nurses followed for 10 years Ayas et al. Arch Intern Med 2003;163:205-9 1.8 1.3 1.1 1.0 5 RR 1.6 1.4 1.2 1.1 1.0 1.4 6 78 9 5 6 78 9 Adjusted for 14 factors Age-adjusted The Nurses’ Health Study
RR CVD, sleep quality and ”need for recovery” after work N=7,944 workers. 18-65 years. 42 cases. Van Amelsvoort et al. Occup Environ Med 2003;60:83-87. Sleep quality Need for recovery Results from 32 months of follow-up of the Maastrict Cohort Study on fatigue 3 2 1 0 1 1 1.22 3.16 2.82 Good Poor Low MediumHigh
RR* Long working hours and short sleep as risk factors for AMI *Adjusted for smoking, alcohol, BMI, BP, DM, cholesterol, heart disease in family, job type and sedentary job Lin er al. Occup Environ Med 2002;59:447-51. Working hours/week past year Days/week with <5 hours of sleep A case control study of working Japanese men 40-79 years of age 260 cases and 445 matched healthy controls <40 41-60 61+ 0 12+ 1 1.3 1.8 1 1.1 2.1
Depression and CHD A meta-analysis RR Clinical depression2.69 (1.63-4.43) Depressive mood1.49 (1.16-1.92) Overall estimate1.64 (1.29-2.08) Rugulies. Am J Prev Med 2002;23:51-61. Relative risk among initially healthy subjects. Analysis of 11 studies
The new fatigue Long working hours Shift work, 24 h society Family/ work conflict High emotional demands High work pace Conflicts, bullying Fatigue Burnout Need for recovery Withdrawal Depression Sleep problems Cardiovascular disease Stress
Is marriage worse than work? (For women) * Adjusted for age, diagnosis, SBP, DM, smoking, lipids and estrogen status. Orth-Gomér et al. JAMA 2000;284:3008-14. A follow-up study of 292 female heart patients in Stockholm LowModerate Severe LowModerate Severe 1 2.8 2.9 1 1.3 (NS) 1.7 (NS) 2 1 0 2 1 0 RR* For new events Marital Stress Work stress
RR* Psychosocial factors and acute myocardial infarction: The INTERHEART STUDY Work stress Home stress Financial stress Life events Rosengren et al. www.the lancet.com Sept. 3,2004:1-10www.the 11,119 cases and 13,648 controls from 52 countries 2 1 0 1 1.38 1 2.14 2.12 1.52 1 1.19 1.33 1 1.23 1.48
Job strain and effort-reward imbalance as predictors of CVD mortality * Adjusted for smoking, physical activity, SBP, cholesterol, BMI, age and occupation. 73 cases. Kivimäki et al. BMJ 2002;325:857-60. A 26 years’ follow-up of 812 Finnish employees LowMedium High LowMedium High 1 1.64 2.22 1 1.91 2.42 2 1 0 2 1 0 RR* Job strain Effort-reward imbalance
Quantitative demands at work: The two dimensions Basic issue: The (mis)match between the amount of work and the time available to do it. Intensity (pace) Extensity (hours) Kristensen et al. Work & Stress 2004;18:305-322.
How should quantitative job demands be measured? I am free from conflicting demands that others make. I have enough time to get the job done. I am not asked to do an excessive amount of work. My job requires working very hard. My job requires working very fast. Do different groups at work demand different things from you that you think are hard to combine? Do you have enough time to do everything? Do you have to work very intensively? Do you have to work very fast? JCQ Whitehall II Each scale seems to measure four different dimensions. Intensive demands? Physical demands? Extensive demands? Role conflicts? Intensive demands? Cognitive demands? Extensive demands? Role conflicts?
We need better measures of job demands “The basic measurement of the demand construct should be improved” (Johnson et al, 1996) “Exposure measurement should be improved, especially for the psychological demand variable” (Steenland et al, 1997) “The measures of psychological job demands need to be refined” (Theorell et al, 1998) “The concept of demands may be too loosely defined” (Hallqvist et al, 1998) Kristensen et al. Work & Stress 2004;18:305-322.
How can we measure quantitative demands? Kristensen et al. Work & Stress 2004;18:305-322. Processes at the (global) labour market. Processes at the workplace and job level. Pressure for increased productivity Mismatch between the amount of work to be done and the time available to do it Pressure for Faster work pace (Intensification) Longer working hours (Extensification) Scale for intensive quantitative demands Basic scale for quantitative demands at work Questions on formal and actual working hours Measures of quantitative job demands. Model for the measurement of quantitative job demands.
Job strain and CHD in Whitehall II 11 years of follow-up of 10,308 employees Fatal CHD + non-fatal MI. A positive study? Kuper & Marmot. J Epidemiol Community Health 2003;57:147-153. H ML H ML L MH L MH Low Passive Active High Men Women Control Demands Job strain 2.0 1.0 0 RR* N.S. 1.0 1.3 1.0 0.7 0.9 1.16 1.14 0.71 1.0 1.9 1.3 1.0 1.2 1.3 1.0 * Adjusted for other risk factors.
II III I I Women Men High Strain Passive Active Low Strain Control Demands Job strain & Whitehall II Kuper & Marmot. J Epidemiol Community Health 2003;57:147-153.
Extending our paradigms Work Demands Control Support Rewards Job insecurity Predictability Meaning of work Rate of change Emotional demands Role conflicts/ambiguities Conflicts/bullying Family/work conflicts Long working hours Irregular working hours Individual (Di)stress Hostility Overcommitment Fatigue Need for recovery Depression Sleep
The association between work and CVD is a major – but somewhat neglected – issue. The new developments in the globalized economy seem to increase CVD risk – at least in the rich countries. Fatigue, burnout, depression and sleep problems seem to be increasing – and to increase CVD risk. Our models, methods, and designs should be improved. Conclusions
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