Projects: Working life, ergonomics, psychosocial factors, and health
The research group takes a main interest in musculoskeletal disorders and psychological distress as consequences of unfavourable working life- and labour market conditions. One area of research is to investigate work life exposures and musculoskeletal disorders and to develop methods for evaluation of ergonomic interventions. Another area of research is to estimate how social and psychosocial factors in early life affect later health and social achievement. We also investigate to what extent such factors, by themselves or in combination with other factors may contribute to health differences between socioeconomic groups, occupations, educational groups, and persons with different psychosocial work environments.
A method for full work day measurements of postures and movements of head, neck, back and upper arms
The Swedish Work Environment Authority and occupational health services (OHS) calls for science-based methods that are user friendly and cost effective. So far, the technical measurements, which are necessary to objectively and precisely measure the impact of interventions in real work, are regarded as too time consuming. The project aims to: (1) with OHS ergonomists produce a very easy method for direct measurement of working postures and movements, which automatically will provide informative printed reports, (2) validate the new method against the existing method, which is currently used by researchers, and (3) test the new method, needed time and ease of use in OHS.
In the new method, the measurements will be started and ended by a gymnastic exercise that takes 20 s. Measurement data is saved on the device's built in memory. When connecting to a computer, an automatic analysis that provides a report with parameters in Excel and as a pdf file will be computed. The report also includes charts, where the current measurement day (possibly group averages) are compared with results from our previous measurements on more than 50 different professions.
The method will be developed and tested together with ergonomists in OHS and is expected to provide a new methodology which, by its usability and its low cost, is attractive for use in the screening of tasks and intervention in jobs where a high exposure (posture, movement speed) for head, neck, back and upper arms are suspected.
Six observational methods for assessment of biomechanical exposures of repetitive work
Occupational health services (OHS) is a key player for the prevention and in supporting organisations’ physical and the psychosocial work environment. According to the Swedish Work Environment Authority, the quality of ergonomic risk assessments is frequently poor; there is a need for systematic, science-based methods with high usability and cost-efficiency.
Musculoskeletal disorders are among the most common causes of reduced work ability in Sweden. Repetitive work is a significant risk factor for the occurrence of injuries in the neck-shoulder and hand-arm.
We have selected six methods for assessment of hand-intensive repetitive work, which are intended to be used by practitioners, and which have previously direct or indirect been validated against health outcomes. In the methods, the observer assesses different components that are weighted together into an index that is the level of risk.
Practitioners will first be trained in the six methods, and will then use the methods for assessment of videotaped tasks of different types and load level. Each method's validity is tested by practitioners' assessments compared with technical measurements. For components in each method that is not possible to measure technically, an expert group consensus estimates will be used. Inter-and intra-observer reliability for each method are studied, as well as their usability and needed time. The methods are also compared with each other concerning the risk indices / risk levels.
The project will provide information on which methods are best suited for practitioners in the risk assessment of work in the tested work tasks. This should increase FHVs use of scientifically developed methods and thereby increase the quality of the risk assessments and provide clearer support for prioritizing actions.
Occupational rehabilitation within municipalities and county councils
The occupational health services (OHS) have potentials to be important actors in facilitating early return to work. There have been attempts from the Swedish government to promote the OHS sector in their early occupational rehabilitation work by a financial support system. However, there is a lack of research into the effects of OHS methods and practices.
The aim of this project is to identify and develop successful methods and practises for the OHS in their early occupational rehabilitation work within health care administrations in municipalities and county councils; methods and practises that facilitate early return to work and contribute to sustainable work ability. The project particularly focuses work ability assessments, adjustments of work, registrations of sick-leave, and the cooperation between OHS and employers, and with other occupational rehabilitation actors.
Data have been collected by a web-based survey to all OHS providers approved by the Swedish Social Insurance Agency (SSIA) and by interviews with representatives for a strategically selected sample of OHS units, administrations in municipalities and county councils that are customers to the selected OHS units, employees on sick-leave from these administrations and SSIA. Also, focus group interviews with unit managers in municipalities, held in the project “Health and future in public sector”, are used. Both quantitative and qualitative analyses of the material are used to identify methods and practises, that the OHS providers, their customers within municipalities and county councils, the SSIA and employees on sick leave, perceive as successful and/or have potentials to be developed and improved. Finally, such methods and practises will, in collaboration with OHSs and administrations in municipalities and county councils, be developed into intervention models.
Cognitive ability, socioeconomic position, psychosocial factors at work, and unemployment as risk factors for alcohol related morbidity and mortality
Alcohol related problems are more common in certain labour market positions than in others although the specific factors that may help to explain such differences are to a large degree unknown. Accumulation of risk factors over the life course may be a part of the explanation. In this research project we will investigate the association between 1) combinations of cognitive ability and level of alcohol consumption or drinking style in late adolescence and risk of ill health and poor social achievement before 60 years of age, 2) job stress according to the demand-control model in middle age and alcohol related morbidity and mortality, 3) unemployment or job loss in middle age and later alcohol related morbidity and mortality, 4) indicators of alcohol related problems up to middle age and risk of later early retirement.
All suggested studies will be based on data from a nation-wide survey of 49 321 young Swedish males, born 1949-51, who were conscripted for compulsory military service in 1969/70. Information from the conscription examination were based on physical examinations, psychological testing (e.g. on cognitive ability) and questionnaires with questions about social circumstances and substance use, e.g. on level of alcohol consumption and about binge drinking. A large amount of information concerning family situation, income, experience of unemployment, hospitalisation and mortality during 1970-2008 has been added to the cohort through record linkages with national registers.
Cognitive ability and psychiatric disease as determinants of life style behaviours, family life, social achievements, later illness, mortality, and early retirement.
During recent years a number of studies have shown associations between cognitive ability measured in early life and mortality up to the age of 76. Suggested explanations of the association between cognitive ability and mortality are: 1) Low cognitive ability could be an indicator of negative living circumstances in early that are associated with later risk of early mortality. 2) Low cognitive ability could predict poor social circumstances in adulthood which in turn is associated with poor health. 3) Low cognitive ability may be associated with inappropriate behavioural factors and poor health. 4) Cognitive ability could be an indicator of “system integrity”, i.e. IQ and other body functions are related.
Psychiatric problems may develop in early life and affect the development of cognitive ability. Negative psychosocial factors in early life are also associated with psychiatric problems and mortality later in life. Poor psychiatric health is also associated with negative social achievements such as increased risk of becoming unemployed or to receive a disability pension.
In this project we are going to investigate to what extent the association between cognitive ability and mortality and morbidity may be explained by an uneven distribution of psychiatric problems and symptoms among person with different cognitive ability among men. The study population consist of almost 50 000 men, born 1949-51, who conscripted for military service in 1969/1970.
The association between childhood IQ and mortality and morbidity among Swedish men and women
An association between cognitive ability in childhood or adolescence and mortality in old age and in mid-life has recently been documented in several studies, although mainly for male populations. A number of mechanisms have been suggested to explain the association between IQ and mortality and morbidity: A low IQ may be the result of early insults to the brain due to insufficient care or other social circumstances in childhood, which also effects adult health, or a low IQ may provide less ability to manage individual health. Adult socioeconomic circumstances could also be assumed to mediate the relationship between IQ and health. In order to gain more knowledge about possible mechanisms more studies on specific health outcomes and diagnoses and studies that include women are needed.
The overall aim of the suggested studies is to extend the knowledge on the association between IQ and mortality and morbidity among women. We will investigate the association between childhood cognitive ability and morbidity and mortality among men and women up to the age of 60. In particular we will investigate the association between IQ and cause-specific mortality, cardiovascular disease, and cancer. The aim is also to investigate to what extent those associations may be explained by social risk factors for mortality and morbidity measured over the life course.
We will use data from the Utvärdering Genom Uppföljning (UGU) database, i.e. cohorts born the years 1948 (n=12 000), 1953 (n=10 000). The collected information in this database is basically of two kinds: school administrative data (e.g. school grade, school and class) collected throughout compulsory school and questionnaire data (e.g. school motivation and cognitive tests (IQ)) collected in grade 6. The cohort will be followed in national registers for hospitalisation and mortality. Information on occupation and socioeconomic position is collected from census information collected every fifth year between 1970 and 1990.
Determinants of reduced work ability
Previous studies have shown that self reported reduced work ability are a strong predictor of later long term sickness absence or early retirement. The concept is complex and not well defined. Several individual and work-related factors related to self-reported work ability have been identified. However, most of the studies are cross-sectional. Determinants for future reduced work ability identified in the few existing longitudinal studies are older age, obesity, low physical capacity, poor health and negative physical and psychosocial work environment factors, for example. These longitudinal studies have been performed on limitid numbers of subjects and often in specific occupational groups. Longitudinal studies on larger polulation-based cohorts are needed to further explore and identify factors that explain the perceptions of reduced work ability among older employed persons.
Information on work ability is collected in the Stockholm Public Health questionnaire 2010 and information on determinants is collected cross-sectionally as well as retrospectively from previous questionnaires and from register information on labour market positions and from health registers. The aim of this project is to identify life course determinants of reduced psychological and physical work ability among men and women in late middle age. We will include information on psychosocial and physical work environment, living conditions, behavioural factors, and health.
The Stockholm Public Health Cohort is a prospective study set within the framework of the Stockholm County Council public health surveys of 2002, 2006, and 2010. In 2010, a new wave of data collection was conducted, including a cross-sectional sample of the background population of Stockholm County, and a follow-up study of the participants enrolled in the 2002 and 2006 surveys (in total 73 000 respondents). Three question on work ability was included in 2010, i.e. work ability in relation psychological and physical demands, respectively, and estimated likelihood of still being in the same occupation within two years ahead.
Precarious Employment in Stockholm (PREMIS)
The globalization of the economy has had a considerable impact on the labor market. Short-term contracts, involuntary self-employment and “staff-for-hire” enterprises are increasingly common. A comprehensive term for this is "precarious employment". Sweden has a long-standing tradition of survey and register-based labor market research of high quality but there are several challenges when investigating precarious employment and health. Firstly, very few studies apply a multi-dimensional approach. Secondly it is likely that many precarious workers don’t qualify for social security schemes or unemployment insurance and cannot properly be traced in the registries. Thirdly, the response rates to most surveys have decreased rapidly over time, especially among those that are most likely to be in precarious employment. Therefore, new sampling methods and improved surveys are needed in addition to current data sources. The PREMIS study has both etiological and methodological aims. The first are to determine if precarious employment is associated to more severe occupational hazards and risk of occupational injury compared to the general working population. Also we are investigating if there is a dose-response relation between precarious employment severity/duration and mental and physical health problems and factors modifying this relation. The methodological objectives include the translation of a multi-dimensional survey tool for precarious employment and to explore how register and survey data can better be used within this field. The project involves researchers from both Sweden and Spain.
Contact person: Theo Bodin
Radiofrequency fields from UMTS phone and sleep and cognitive functions
The number of mobile phone users has increased rapidly during the last 15 years, but there is a remaining concern for negative health effects. Effects on the brain’s electrical activity (EEG), sleep and cognitive functions have been reported in some studies, while other studies have failed to identify any influence of radiofrequency fields (RF). In an earlier study we observed an effect on sleep (decreased time for deep sleep) and spatial memory after three hours exposure to RF (884 MHz, SAR 1,4 W/kg). In the present study we will build on these results and study possible effects of a three hour exposure to UMTS (3G) in a group of teenagers. The study is performed in collaboration with the Stress Research Institute, Stockholm University.
Specific hypotheses to be tested are that exposure to UMTS leads to decrease in deep sleep, increase in power density in EEG alpha and spindle frequency bands, improved performance in cognitive tests and headache. The study has a double blind crossover-design as the earlier study, but with an increase in the number of exposure sessions (UMTS or sham) per participant. The study group will be 20 subjects age 16 to 19.
Sleep quality and multisite pain
Sleep problems are associated with sickness absence and with pain. By analyzing data from the MUSIC-Norrtälje study we will study a possible association between self-reported sleep quality and multisite pain five years later. The MUSIC-Norrtälje study was initiated in order to identify and quantify risk factors and protective factors for LBP and NSP, and to investigate the prognoses of these disorders. The Norrtälje Study was at baseline case-referent study (1994-1996), with five-year follow-up including men and women, 20-59 years old living and working in Norrtälje. The present study consists of 2329 subjects who participated both at baseline and at follow-up. The questionnaire at baseline and follow-up includes questions on sleep (Karolinska Sleep Questionnaire) and on musculoskeletal pain (Von Korff and The Standard Nordic Questionnaire). Hypotheses tested in this study are whether good or bad sleep will predict onset of or restoration from multisite pain five years later.
Sleep quality and sickness absence among individuals with low-back or neck-shoulder pain
Sleep problems are associated with sickness absence and with pain. By analyzing data from the MUSIC-Norrtälje study we will study a possible association between self-reported sleep quality and sickness absence during five subsequent years. The MUSIC-Norrtälje study was initiated in order to identify and quantify risk factors and protective factors for LBP and NSP, and to investigate the prognoses of these disorders. The Norrtälje Study was at baseline case-referent study (1994-1996), with five-year follow-up including men and women, 20-59 years old living and working in Norrtälje. Census data from the National Social Insurance Board on sickness absence were linked to each of the 2329 subjects who participated in both the baseline study and follow-up. The questionnaire at baseline and follow-up includes questions on sleep (Karolinska Sleep Questionnaire) and on musculoskeletal pain (Von Korff and The Standard Nordic Questionnaire). The hypothesis tested in this study is whether bad sleep predicts sickness absence during the five subsequent years in subjects who reported low back pain and/or neck shoulder pain at baseline.
HRV and sleep quality exposure to stressors
There is a known association between tinnitus on one hand and depression, anxiety and stress on the other. In addition to this, hearing disabilities are associated to an increased risk of mood disorders among adults. In this study, tinnitus, hearing problems as well as questionnaire data concerning common symptoms of stress will be regarded as indicators of stress and analyzed in relation to nocturnal HRV (heart rate variability). By studying twins we will also be able to investigate the relative importance of stress and genetic factors on HRV and the sympatho-vagal balance.
This cross-sectional study is a collaboration with the Twin Hearing Study. Male twins born 1926 to 1958 and who participated in a prior study published 1997 are recruited from the Swedish Twin Registry. Data on self-reported sleep (Karolinska Sleep Diary), 24 hour heart rate variability (HRV) and reported stress during the day prior the measurements has been assessed during 2010-2013. Subjective and objective data on hearing are assessed as part of the Twin Hearing Study. Correlations between self-reported sleep quality and stress, hearing disabilities, tinnitus and HRV parameters will be analyzed. In a first step, twin analysis will be conducted with tests for correlation of HRV traits for monozygotic twins and dizygotic twins, according Falconer`s formula. Further analysis with structural equation models will be conducted if number of subjects can assume enough power. In total, data have been assessed in 202 individuals (44 monozygotic pairs, 28 dizygotic pairs, 58 singletons).
Sleep quality in patients with work-related psychological disorders
MiiNA is a new short term individually targeted intervention program based on interviews and diagnostic tools for patients with new onset work-related psychological disorders. For evaluation of the intervention program, data on subjective sleep (Karolinska Sleep diary) and objective sleep (Actiwatch) is assessed together with a self-administered questionnaire concerning psychological health including HAD (Hospital Anxiety and Depression scale), EQ-5D, SMBM - Shirom, Melamed Burnout Measure and WAI (Work Ability Index). Data is assessed before the intervention, directly after the intervention and six months after intervention. In all, data from approximately 30 individuals participating in MiiNA and 30 controls (receiving treatment as usual) will be assessed. The intervention program (MiiNA) is targeted towards occupational health care units, and participants (patients) are recruited through caregivers who have received training for MiiNA. The correlation between sleep (objective and subjective) and self-rated changes of psychological health will also be calculated in order to investigate whether sleep quality will influence the effect of the intervention program.