SJWEH - Online-first articles

Association between change in employment status and new-onset depressive symptoms in South Korea � a gender analysis

Mon, 27 Feb 2012 16:39:17 +0200

Objectives This study aimed to investigate the association of change in employment status with new-onset depressive symptoms, particularly differences stemming from workers� gender, in South Korea. Methods We analyzed data from the ongoing Korean Welfare Panel Study. After excluding participants who had depressive symptoms at baseline (2007), we analyzed 2891 participants who became a precarious or permanent worker or unemployed at follow-up (2008) among waged workers who were permanent or precarious workers at baseline. Workers were classified as permanent workers if they had full-time, secure jobs and were directly hired by their employers; workers not meeting all these criteria were classified as precarious workers. Depressive symptoms were assessed annually using the 11-item Center for Epidemiologic Studies Depression Scale. To reduce potential bias due to pre-existing health conditions, we also examined the association in a subpopulation excluding participants with any pre-existing chronic disease or disability. Results Compared to those who maintained permanent employment, workers who became unemployed following precarious employment had higher odds of developing depressive symptoms [odds ratio (OR) 2.30, 95% confidence interval (95% CI) 1.01�5.25]. In gender-stratified analyses, new-onset depressive symptoms were strongly associated with the change from precarious to permanent employment (OR 2.57, 95% CI 1.20�5.52) as well as the change from permanent to precarious employment (OR 2.88, 95% CI 1.24�6.66) among females; no significant association was observed in the male subpopulation. Conclusions This study found that changes from precarious to permanent work or from permanent to precarious work were associated with new-onset depressive symptoms among South Korean women. by Kim S-S, Subramanian SV, Sorensen G, Perry MJ, Christiani DC. doi:10.5271/sjweh.3285

Risk factors for incidence of rotator cuff syndrome in a large working population

Mon, 27 Feb 2012 14:28:36 +0200

Objectives The aim of this study was to assess the effects of personal and work-related factors on the incidence of rotator cuff syndrome (RCS) in a large working population. Methods A total of 3710 French workers were included in a cross-sectional study in 2002�2005. All completed a self-administered questionnaire about personal factors and work exposure. Using a standardized physical examination, occupational physicians established a diagnosis of RCS. Between 2007�2010, 1611 workers were re-examined. Associations between RCS and risk factors at baseline were analyzed by logistic regression. Results A total of 839 men and 617 women without RCS at baseline were eligible for analysis. RCS was diagnosed in 51 men (6.1%) and 45 women (7.3%). The risk of RCS increased with age for both genders [odds ratio (OR) 4.7 (95% confidence interval [95% CI] 2.2�10.0) for men aged 45�49 years and 5.4 (95% CI 2.3�13.2) for women aged 50�59 years; reference <40 years]. For men, the work-related risk factors were repeated posture with the arms above the shoulder level combined with high perceived physical exertion [OR 3.3 (95% CI 1.3�8.4)] and low supervisor support [OR 2.0 (95% CI 1.1�3.9)]. For women, working with colleagues in temporary employment [OR 2.2 (95% CI 1.2�4.2)] and repeated arm abduction (60�90�) [OR 2.6 (95% CI 1.4�5.0)] were associated with RCS. Conclusions Age was the strongest predictor for incident cases of RCS, and arm abduction was the major work-related risk factor for both genders. Lack of social support was a predictor for RCS among men. by Bodin J, Ha C, Petit Le Manac�h A, S�razin C, Descatha A, Leclerc A, Goldberg M, Roquelaure Y. doi:10.5271/sjweh.3284

Mortality attributable to occupational exposure in Sweden

Wed, 22 Feb 2012 16:32:56 +0200

Objectives The objective of this study was to estimate the mortality from cancer, cardiovascular, and respiratory diseases attributable to occupational exposure in Sweden. Methods Estimates were calculated for men and women separately, and we considered only deaths between 25�74 years of age. We considered cancer exposures/sites classified as I or 2a according to the International Agency for Research on Cancer (IARC). Acute myocardial infarction was the only included cardiovascular disease. Respiratory diseases comprised chronic obstructive pulmonary disease (COPD) asthma, pneumoconiosis and alveolitis. All deaths of pneumoconiosis and alveolitis were considered work-related. Estimates were based on the Swedish mortality in 2007. Results In total, we estimate that there are about 800 work-related deaths per year in the studied causes. The majority are due to acute myocardial infarction, with 126 deaths among women and 337 deaths among men attributable to job strain, shift work, exhaust gases, combustion products, or environmental tobacco smoke (ETS). There are 99 respiratory disease-related deaths, the vast majority from COPD (N=92). In total, 270 cancer deaths are estimated to be work-related. For men, half of the cases are attributed to asbestos exposure. Conclusions Our results indicate that preventive measures to decrease occupational mortality should consider factors associated with myocardial infarction such as job strain, shift work and exhaust gases from vehicles and combustion products. Exposures to factors associated with COPD, such as dust, also seem important to prevent. by J�rvholm B, Reuterwall C, Bystedt J. doi:10.5271/sjweh.3283

The association between study characteristics and outcome in the relation between job stress and cardiovascular disease � a multilevel meta-regression analysis

Tue, 21 Feb 2012 01:36:11 +0200

Objectives Studies about job strain and cardiovascular disease (CVD) have yielded inconsistent results, which hinders making a firm conclusion about the association. Inconsistent findings may be the result of methodological differences. If the relative CVD risk is influenced by methodological differences, these differences should be explored in more detail in future research to clarify which methodological characteristics are inherent to obtain the most accurate estimate between job strain and CVD risk. By assessing how study characteristics are associated with the outcome, we take the first step in unraveling this association. In this review, we explore the following research question: are study characteristics associated with the size of the reported relative CVD risk? Methods A systematic literature search yielded 71 studies about job stress, assessed with the demand�control model, and CVD. Traditional meta-regression was extended enabling the use of correlated data to quantify heterogeneity within and between studies. Results Compared to studies that use the original Job Content Questionnaire (JCQ), studies in which a more deviant form of the JCQ was used yielded, on average, 43% higher estimates. Studies conducted in the USA yielded about 26% lower estimates compared to studies conducted in Scandinavian countries. Conclusions Several study characteristics are associated with the size of the reported relative CVD risk. Many of these study features are related to the validity of the exposure and outcome assessment and are inherent to obtain an accurate estimate between work stress and CVD risk. More research is needed to clarify why these study features impact the average relative CVD risk. by Szerencsi K, van Amelsvoort LGPM, Viechtbauer W, Mohren DCL, Prins MH, Kant I. doi:10.5271/sjweh.3282

Work at night and breast cancer � report on evidence-based options for preventive actions

Mon, 20 Feb 2012 16:31:31 +0200

In 2007, the International Agency for Research on Cancer classified shift work involving circadian disruption as probably carcinogenic to humans (group 2A), primarily based on experimental and epidemiologic evidence for breast cancer. In order to examine options for evidence-based preventive actions, 16 researchers in basic, epidemiological and applied sciences convened at a workshop in Copenhagen 26�27 October 2011. This paper summarizes the evidence from epidemiological and experimental studies and presents possible recommendations for prevention of the effects of night work on breast cancer. Among those studies that quantified duration of shift work, there were statistically significant elevations in risk only after about 20 years working night shift. It is unclear from these studies whether or not there is a modest but real elevated risk for shorter durations. Hence, restriction of the total number of years working night shift could be one future preventive recommendation for shift workers. The diurnal secretion of melatonin by the pineal gland with peak in secretory activity during the night is a good biochemical marker of the circadian rhythm. Disruption of the diurnal melatonin secretion pattern can be diminished by restricting the number of consecutive night shifts. Reddish light and reduced light intensity during work at night could potentially help diminish the inhibitory activity of light with strong intensity on the melatonin secretion, but further mechanistic insight is needed before definite recommendations can be made. Earlier or more intensive mammography screening among female night shift worker is not recommended because the harm�benefit ratio in this age group may not be beneficial. Preventive effects of melatonin supplementation on breast cancer risk have not been clearly documented, but may be a promising avenue if a lack of side effects can be shown even after long-term ingestion. Women with previous or current breast cancer should be advised not to work night shifts because of strong experimental evidence demonstrating accelerated tumor growth by suppression of melatonin secretion. Work during the night is widespread worldwide. To provide additional evidence-based recommendations on prevention of diseases related to night shift work, large studies on the impact of various shift schedules and type of light on circadian rhythms need to be conducted in real work environments by Bonde JP, Hansen J, Kolstad HA, Mikkelsen S, Olsen JH, Blask DE, H�rm� M, Kjuus H, de Koning HJ, Olsen J, M�ller M, Schernhammer ES, Stevens RG, �kerstedt T. doi:10.5271/sjweh.3281

Pupils with special educational needs in basic education schools and teachers� sickness absences � a register-linkage study

Fri, 17 Feb 2012 02:31:32 +0200

Objectives We examined whether having a high percentage of pupils with special educational needs (SEN) in basic education schools increases the risk of sickness absence among teachers and whether this risk is dependent on the pupil�teacher ratio (PTR), an indicator of teacher resources at school. Methods We obtained register data on 8089 teachers working in 404 schools in 10 municipalities in Finland during the school year 2004�2005. We used multilevel multinomial regression models to examine the risk of teachers� short- and long-term sickness absence in relation to the percentage of SEN pupils and the PTR at school. We tested the equality of trends in groups with high and low PTR using PTR � SEN interaction term. Results After adjustment for teacher and school characteristics, the risk for long-term absences was higher among teachers at schools with a high percentage of SEN pupils than among teachers at schools with a low percentage of SEN pupils [odds ratio (OR) 1.5, 95% confidence interval (95% CI) 1.2�1.8). This was also the case for short-term absences (OR 1.4, 95% CI 1.2�1.7). In analyses stratified by the PTR levels, the association between the percentage of SEN pupils and long-term absences was 15% higher among teachers with a high PTR than among those with a low PTR (P for interaction=0.10). Conclusions Teachers� sickness absenteeism seems to increase with a higher percentage of SEN pupils, especially when the PTR is high. Teacher resources at schools that have a high percentage of SEN pupils should be well maintained to ensure the health of teachers. by Ervasti J, Kivim�ki M, Kawachi I, Subramanian SV, Pentti J, Ahola K, Oksanen T, Pohjonen T, Vahtera J, Virtanen M. doi:10.5271/sjweh.3279

Cognitive function among sons of women who worked in dentistry

Fri, 10 Feb 2012 17:01:41 +0200

Objective Exposure to elemental mercury vapor can impair neurological function as it is neurotoxic in doses higher than usually found in dentistry. Little is known about the potential effects of fetal exposure to elemental mercury among offspring of female dental workers. We investigated cognitive function among offspring of women working in dentistry at the time of their pregnancy. Methods We compared results for cognitive function examinations taken by the majority of young men in Sweden at the time of compulsory military enlistment (age 17�18 years). Sons of female dentists (N=365) and dental nurses (N=3181) born during the 1960�1970s were compared with sons of female physicians (N=378) and assistant nurses (N=12 667). Results Analysis by linear regression showed that sons of dental workers had similar or higher cognitive function test results compared to their matched cohorts. Conclusion We found no evidence of poorer cognitive function among male offspring of female dentists or dental nurses. by Naimi-Akbar A, Sandborgh-Englund G, Ekbom A, Ekstrand J, Montgomery S. doi:10.5271/sjweh.3278

Bullying at work and onset of a major depressive episode among Danish female eldercare workers

Thu, 02 Feb 2012 05:13:26 +0200

Objective The aim of this study was to analyze whether exposure to workplace bullying among 5701 female employees in the Danish eldercare sector increases the risk of onset of a major depressive episode (MDE). Methods Participants received questionnaires in 2004�2005 and again in 2006�2007. MDE was assessed with the Major Depression Inventory. We examined baseline bullying as a predictor of onset of MDE at follow-up using multiple logistic regression. We further conducted a cross-sectional analysis at the time of follow-up among participants who at baseline were free of bullying, MDE, and signs of reduced psychological health. Finally, we analyzed reciprocal effects, by using baseline bullying and baseline MDE as predictors for bullying and MDE at follow-up. Results Onset rates of MDE in the groups of no, occasional, and frequent bullying were 1.5%, 3.4%, and 11.3%, respectively. Odds ratios (OR) for onset of MDE were 2.22 [95% confidence interval (95% CI) 1.31�3.76] for occasional bullying and OR 8.45 (95% CI 4.04�17.70) for frequent bullying, after adjustment for covariates. In the cross-sectional analysis, OR were 6.29 (95% CI 2.52�15.68) for occasional bullying and 20.96 (95% CI 5.80�75.80) for frequent bullying. In the analyses on reciprocal effects, both baseline bullying [occasional: OR 2.12 (95% CI 1.29�3.48) and frequent: OR 6.39 (95% CI 3.10�13.17)] and baseline MDE [OR 7.18 (95% CI 3.60�14.30] predicted MDE at follow-up. However, only baseline bullying [occasional: OR 7.44 (95% CI 5.94�9.31) and frequent: OR 11.91 (95% CI 7.56�18.77)] but not baseline MDE [OR 0.93 (95% CI 0.47�1.84)] predicted bullying at follow-up. Conclusions Workplace bullying increased the risk of MDE among female eldercare workers. MDE did not predict risk of bullying. Eliminating bullying at work may be an important contribution to the prevention of MDE. by Rugulies R, Madsen IEH, Hjarsbech PU, Hogh A, Borg V, Carneiro IG, Aust B. doi:10.5271/sjweh.3277

How should methods for return to work be evaluated?

Mon, 30 Jan 2012 16:34:11 +0200

Measures to decrease early retirement are underway in many countries to increase the working population and lower costs. Sick leave is the normal pathway to early retirement and methods to enable persons on sick leave to return to work (RTW) earlier and at a higher rate are in focus. Using the term �RTW�, a search in PubMed resulted in about 300 papers, of which more than half have been published after 2008 and 20% during the last year alone. RTW has been the focus of many submitted and published papers in the Scandinavian Journal of Work, Environment and Health. In this issue, Aust and coworkers (1) describe a large randomized Danish study to investigate if support by a trained staff will increase RTW. It is probably the largest ongoing RTW evaluation at the moment. The design is similar to studies of pharmaceutical drugs in phase III, involving a multicenter approach, evaluation committee, cost�benefit analyses, trial registration, and a huge budget. In contrast to most previous studies, it does not focus on a single diagnosis but on estimated prognosis. Established after a literature review, the intervention method is described as �biopsychosocial� (2). Compared to most other studies in this area, the Aust et al study has a high power. A recent systematic review of community and work-based measures to reduce sick leave among persons with musculoskeletal disorders found that the published literature consisted of rather small studies of limited quality. Furthermore, the effect was overestimated through biased publishing of positive studies (3). Modifications to work and contacts with the employer are often emphasized as important for RTW. Decreasing working time and changing work tasks increased RTW in a Finnish controlled study of persons with musculoskeletal disorders (4), and stress management at work decreased absenteeism in a Danish study (5). Furthermore, a randomized study of persons with severe psychiatric illness involving six countries found that individual support involving contact with the employer increased the chance for RTW (6). In contrast, contact with healthcare doctors seem to be of limited importance for RTW (7). In fact, a small controlled trial where less experienced doctors were trained by more senior colleagues actually increased the sick leave (8). It would be of great interest to understand better the mechanistic aspects of contacts with employers for RTW. One cause may be modification of the workplace or tasks, but it can also be that the employer is persuaded to accept a lower productivity. It is probable that people on sick leave have lower productivity and the decrease may persist also when returning to work. Persons who returned to work from sick leave for low-back pain were found to have a lower productivity still 12 months after the sick leave ended (9). While there is a high interest to increase RTW, there are few studies of the adverse effects of too early RTW. In 1955, when sick leave was granted to the entire population in Sweden through a government-financed system, a major argument was to protect the sick worker from further impairment due to harmful factors at work and enable a more rapid recovery (10). In a recent report, even the OECD acknowledged the need for people to be on sick leave and argued �cutting benefit entitlements for people who are already suffering from ill-health and forcing them to undergo training or even seek work is both highly unpopular and not fair for some groups� (11). However, they did not define the �groups� that should be on sick leave. Adverse effects may be through presenteeism (ie, coming to work when sick) or unemployment. Presenteeism is a predictor of impaired health at least in some circumstances (12). A sick person may be susceptible to harm from occupational factors that normally do not harm healthy persons. A study by Kivim�ki et al (13) found that severe coronary events were more common among unhealthy persons without sickness absence compared to unhealthy persons with sickness absence. The Viikari-Juntura et al study (4) indicated no adverse effects of early RTW as interruption of part-time sick leave due to exacerbation of symptoms or in symptom severity. It is argued that work is good for mental health (11), while a study found that disability pension seemed to improve mental symptoms especially among those with chronic diseases (14). There are probably people on sick leave whose health is improved by being on sick leave, individuals whose health is impaired by being on sick leave, and individuals whose health neither improves nor declines. An ideal method for the evaluation of RTW should be able to identify those whose health is impaired by too early RTW. Unemployment may be an adverse effect of RTW as there are indications that unemployment per se impairs health (15). It is uncertain if RTW is a benefit to everyone who is transferred from being patients on sick leave to clients in job centers. From a work labor perspective, it is often argued that unemployment is better than sick leave as the latter may lead to permanent withdrawal from the work force due to disability pension (11). Adverse effects occurring after several years are especially difficult to study, but the Nordic countries have probably better chances to conduct such studies due to their good data registers. RTW programs may strongly depend on context. Programs that work in countries and time periods in which there is a shortage of manpower may work differently under other circumstances. While good pharmaceutical studies usually are considered to have a strong external validity, RTW studies with a good external validity have to focus on a variable context. There is a need to develop effective methodologies for evaluation of RTW. Just copying the corresponding methodologies for pharmaceutical drugs is not enough. Studying adverse effects and contextual factors and understanding mechanisms are often a greater challenge in RTW studies over and above difficulties relating to blinding and randomization. The Danish study is a step forward and will probably set a new standard, but there is always room for progress. by J�rvholm B. doi:10.5271/sjweh.3276

Hazard functions to describe patterns of new and recurrent sick leave episodes for different diagnoses

Fri, 27 Jan 2012 17:39:28 +0200

Objectives This study aims to identify the hazard functions that describe the occurrence patterns of new and recurrent sick leave (SL) episodes for mental, respiratory, and musculoskeletal diagnoses. Methods The data come from a cohort of workers in the Hospital das Cl�nicas da Universidade Federal de Minas Gerais, Brazil, including all employees working ≥20 hours per week, whose first employment relation with the hospital started between 1 January 2000 and 31 December 2007 (N=1579). We created 15 samples corresponding to combinations of diagnoses causing SL and the number of previous episodes already suffered. We fitted Weibull, log-normal, and log-logistic models by resampling and selected the model having the lowest Akaike information criterion in the greatest number of resamples. Results Differences were observed in the probability distributions associated with the process generating a SL. Diagnosis showed important differences in terms of risk intensity: mental episodes were the least frequent. There were differences in risk intensity and shape of the function over time depending on the episode number, particularly between the first episode and recurrences. In addition, these differences varied by diagnosis. Conclusions In most of the samples analyzed, we identified a mixture of distributions, implying a need to revise the statistical methods of analysis for SL occurrence with the aim of obtaining consistent estimates of the risk and the associated factors. by Navarro A, Mori�a D, Reis R, Nedel FB, Mart�n M, Alvarado S. doi:10.5271/sjweh.3275

A systematic review of the cost-effectiveness of worksite physical activity and/or nutrition programs

Tue, 24 Jan 2012 02:06:52 +0200

Objective The aim of this study was to appraise and summarize the evidence on the cost-effectiveness of worksite physical activity and/or nutrition programs. Methods We searched EMBASE, MEDLINE, SportDiscus, PsycInfo, NIOSHTIC-2, NHSEED, HTA, and Econlit for studies published up to 14 January 2011. Additionally, we searched for articles by reviewing references, searching authors� databases, and contacting authors of included studies. Two researchers independently selected articles. Articles had to include a cost-effectiveness and/or cost-utility analysis comparing a worksite physical activity and/or nutrition program to usual care or an abridged version of the program. Data were extracted on study characteristics and results. Two researchers independently assessed the risk of bias using the Consensus on Health Economic Criteria list (CHEC-list). Results Ten studies (18 programs) were included. More than 50% of the studies fulfilled 11 (58%) of the 19 CHEC-list items. From various perspectives, worksite nutrition and worksite physical activity and nutrition programs (N=6) were more costly and more effective in reducing body weight than usual care. When only intervention costs were considered, most worksite nutrition (N=4/5) and worksite physical activity and nutrition programs (N=5/6) were more costly and more effective in reducing cholesterol level and cardiovascular disease risks, respectively. Conclusions The cost-effectiveness of more costly and more effective programs depends on the �willingness to pay� for their effects. It is unknown how much decision-makers are willing to pay for reductions in body weight, cholesterol level, and cardiovascular disease risks. Therefore, conclusions about the cost-effectiveness of worksite physical activity and/or nutrition programs cannot be made. There is substantial need for improvement of the methodological quality of studies and particular emphasis should be placed on the handling of uncertainty. by van Dongen JM, Proper KI, van Wier MF, van der Beek AJ, Bongers PM, van Mechelen W, van Tulder MW. doi:10.5271/sjweh.3274

Unrecognized risks of nickel-related respiratory cancer among Canadian electrolysis workers

Wed, 18 Jan 2012 23:15:54 +0200

Objectives Nickel compounds, inclusive of water-soluble salts, have been classified as human carcinogens by the International Agency for Research on Cancer (IARC). Nickel producers have disputed the classification of soluble nickel compounds for three decades with reference to an alleged absence of excess respiratory cancer among Canadian nickel-exposed electrolysis workers. We evaluated historical data from two electrolytic refineries in Ontario, both included in prominent Canadian reports on occupational nickel-related cancer. Methods For Port Colborne nickel refinery (PCNR) and Copper Cliff copper refinery (CCCR), we identified process descriptions, exposure estimates, and original reports on cancer mortality using reference lists, libraries, and state archives. The documents were written or published between 1930 and 1992. Results For PCNR, a 1977 US National Institute of Occupational Safety and Health criteria document demonstrated an excess nasal cancer risk among electrolysis workers independent of furnace exposure. PCNR studies published after 1980 excluded 26% of long-term refiners who died from respiratory cancer according to earlier reports, and 42% of the workers had unknown vital status at the end of follow-up, biasing the standardized observed-to-expected mortality ratios downwards, most pronounced in recent reports and for workers without pension or company benefits. CCCR reports did not adequately address soluble nickel exposure in the evaluation of an observed occupational lung cancer excess. Conclusions While acknowledging important contributions to the recognition of nickel carcinogenicity from highly exposed Canadian refiners, we conclude that the claimed absence of nickel-related respiratory cancer among electrolysis workers has resulted from an arbitrary overemphasis of biased and inconclusive findings by Grimsrud TK, Andersen A. doi:10.5271/sjweh.3273

Professional driving and prolapsed lumbar intervertebral disc diagnosed by magnetic resonance imaging � a case�control study

Mon, 16 Jan 2012 18:00:01 +0200

Objectives The aim of this study was to investigate whether whole-body vibration (WBV) is associated with prolapsed lumbar intervertebral disc (PID) and nerve root entrapment among patients with low-back pain (LBP) undergoing magnetic resonance imaging (MRI). Methods A consecutive series of patients referred for lumbar MRI because of LBP were compared with controls X-rayed for other reasons. Subjects were questioned about occupational activities loading the spine, psychosocial factors, driving, personal characteristics, mental health, and certain beliefs about LBP. Exposure to WBV was assessed by six measures, including weekly duration of professional driving, hours driven at a spell, and current 8-hour daily equivalent root-mean-square acceleration A(8). Cases were sub-classified according to whether or not PID/nerve root entrapment was present. Associations with WBV were examined separately for cases with and without these MRI findings, with adjustment for age, sex, and other potential confounders. Results Altogether, 237 cases and 820 controls were studied, including 183 professional drivers and 176 cases with PID and/or nerve root entrapment. Risks associated with WBV tended to be lower for LBP with PID/nerve root entrapment but somewhat higher for risks of LBP without these abnormalities. However, associations with the six metrics of exposure were all weak and not statistically significant. Neither exposure�response relationships nor increased risk of PID/nerve root entrapment from professional driving or exposure at an A(8) above the European Union daily exposure action level were found. Conclusions WBV may be a cause of LBP but it was not associated with PID or nerve root entrapment in this study. by Palmer KT, Griffin M, Ntani G, Shambrook J, McNee P, Sampson M, Harris EC, Coggon D. doi:10.5271/sjweh.3272

The Danish national return-to-work program � aims, content, and design of the process and effect evaluation

Fri, 13 Jan 2012 18:41:24 +0200

The Danish national return-to-work (RTW) program aims to improve the management of municipal sickness benefit in Denmark. A study is currently ongoing to evaluate the RTW program. The purpose of this article is to describe the study protocol. The program includes 21 municipalities encompassing approximately 19 500 working-age adults on long-term sickness absence, regardless of reason for sickness absence or employment status. It consists of three core elements: (i) establishment of multidisciplinary RTW teams, (ii) introduction of standardized workability assessments and sickness absence management procedures, and (iii) a comprehensive training course for the RTW teams. The effect evaluation is based on a parallel group randomized trial and a stratified cluster controlled trial and focuses on register-based primary outcomes � duration of sickness absence and RTW � and questionnaire-based secondary outcomes such as health and workability. The process evaluation utilizes questionnaires, interviews, and municipal data. The effect evaluation tests whether participants in the intervention have a (i) shorter duration of full-time sickness absence, (ii) longer time until recurrent long-term sickness absence, (iii) faster full RTW, (iv) more positive development in health, workability, pain, and sleep; it also tests whether the program is cost-effective. The process evaluation investigates: (i) whether the expected target population is reached; (ii) if the program is implemented as intended; (iii) how the beneficiaries, the RTW teams, and the external stakeholders experience the program; and (iv) whether contextual factors influenced the implementation. The program has the potential to contribute markedly to lowering human and economic costs and increasing labor force supply. First results will be available in 2013. The trial registrations are ISRCTN43004323, and ISRCTN51445682. by Aust B, Helverskov T, Nielsen MBD, Bjorner JB, Rugulies R, Nielsen K, S�rensen OH, Grundtvig G, Andersen MF, Hansen JV, Buchardt HL, Nielsen L, Lund TL, Andersen I, Andersen MH, Clausen AS, Heinesen E, Mortensen OS, Ektor-Andersen J, �rb�k P, Winzor G, B�ltmann U, Poulsen OM. doi:10.5271/sjweh.3271

Occupational exposure to particles and incidence of stroke

Fri, 13 Jan 2012 01:52:10 +0200

Objectives This paper aims to investigate the relation between occupational exposure to particles, particle size, and the incidence of ischemic and hemorrhagic stroke. Methods The cohort included all manual workers identified from the Swedish National Census in 1980, who were alive as of 1 January 1987. First time events of ischemic or hemorrhagic stroke during the period 1987�2005 were identified through linkage to the Hospital Discharge Register and the National Cause of Death Register. A job-exposure matrix for exposure to small (<1 �m) and large (>1 �m) particles was developed and applied. Hazard ratios (HR) were estimated by Cox regression with adjustment for age, socioeconomic group, and residential area. Results Increased HR of ischemic as well as hemorrhagic stroke were found among both women and men occupationally exposed to small as well as large particles. The risks were higher for workers exposed for ≥5 years compared to �ever exposed� participants indicating a dose�response relationship, but no trend with exposure intensity was observed. The risks were generally higher for women than men. Conclusions Occupational exposure to small and large particles was associated with increased risks of ischemic and hemorrhagic stroke. Further studies are needed to explore the relationships between exposure to different types of particles and various doses and the occurrence of stroke among women as well as men. by Sj�gren B, L�nn M, Feychting M, Nise G, Kauppinen T, Plato N, Wiebert P, Gustavsson P. doi:10.5271/sjweh.3270

The placebo effect revisited � author response

Wed, 11 Jan 2012 19:06:41 +0200

Our randomized controlled trial showed a reduction of neck/shoulder pain and headache in response to 10 weeks of resistance training performed for 2 minutes a day (1, 2). We used a pragmatic approach and did not investigate the mechanism of pain reduction. It is well known that placebo can influence subjective outcomes. In the original article outlining the primary outcomes, we briefly discussed this: �Because blinding of participants in training studies is not possible, we cannot exclude the influence of placebo effects. However, the effect-size of changes in our study exceeds those previously reported in response to placebo� (2, p444). We mentioned that the effect size in our study (~0.5) exceeded those typically observed for placebo, with reference to a Cochrane Review for all clinical conditions (placebo effect size ~0.3) (3). Obviously this does not exclude that placebo effects influenced our findings. In their commentary �The placebo effect revisited�, Andersen & Mikkelsen (4) referenced a meta-analysis on osteoarthritis (OA) showing effects sizes >0.5 for placebo. Our participants did not suffer from OA, but were generally healthy office workers with frequent neck/shoulder pain. In our study, we had three intervention groups: (i) 2 minutes of daily resistance training, (ii) 12 minutes of daily resistance training, (iii) weekly information on different health related aspects (control group). Because blinding is not possible in behavioral interventions and to avoid different outcome expectations between groups, we explained to the participants prior to randomization that none of the three interventions was known to be superior to the others. Of course, this does not guarantee that the three groups had similar outcome expectations. In hindsight, specific questions about outcome expectations � as suggested by Andersen & Mikkelsen (4) � could have provided additional valuable information. Due to the possible influence of placebo, studies investigating the effect of behavioral interventions on pain conditions should include outcomes other than subjective pain only. For this reason, we also included a manual palpation test on muscle tenderness performed by a physical therapist and a muscle strength test performed by an exercise physiologist. During these tests, the examiners remained blinded to group allocation. These tests showed a decrease in muscle tenderness and an increase in muscle strength at 10-week follow-up in the 2- and 12-minute groups compared with the control group (2), indicating that mechanisms beside placebo influenced our findings. Andersen & Mikkelsen (4) state in their commentary that biological effects of such brief training bouts are not plausible. In our study, the 2-minute group performed a single set of resistance exercise with as many repetitions as they could (ie, until momentary muscular fatigue). Electrophysiological measurements show that this results in marked acute neuromuscular changes (5). Several research groups have documented physiological adaptations � both neural and muscular � in response to training interventions using single-set resistance exercise for different muscle groups in healthy volunteers (6). Thus, based on the literature, it is plausible that physiological changes can occur in response to brief resistance exercises bouts. Whether such changes are causally related to pain reduction is unknown. Hopefully, our study will prompt future research on the mechanisms of pain reduction in response to brief resistance exercise bouts. by Andersen LL. doi:10.5271/sjweh.3269

The joint association of sleep duration and insomnia symptoms with disability retirement � a longitudinal, register-linked study

Tue, 10 Jan 2012 21:05:21 +0200

Objective The aim of this study was to examine the joint association of sleep duration and insomnia symptoms with subsequent disability retirement. Methods Baseline survey data were collected in 2000�2002 from 40�60-year-old employees of the City of Helsinki, all working at baseline. Baseline data were linked with disability retirement data until the end of 2010, obtained from the Finnish Centre for Pensions registers (N=6042). Sleep duration and self-reported insomnia symptoms (difficulties in initiating and maintaining sleep and non-restorative sleep) were derived from the baseline surveys. All-cause disability retirement (N=561) and the most prevalent diagnostic groups � musculoskeletal diseases (43%) and mental disorders (26%) � were examined. Cox regression analysis was used to yield hazard ratios (HR) with 95% confidence intervals (CI). Results A joint association of sleep duration and insomnia symptoms with disability retirement was found, implying a higher risk for those with frequent insomnia symptoms. HR for all-cause disability retirement ranged among those with frequent symptoms from 2.02 (95% CI 1.53�2.68, sleeping 7 hours) to 3.92 (95% CI 2.57�5.97, sleeping ≤5 hours). Adjusting for sociodemographic, work-related factors and health attenuated the associations, which nevertheless remained. The associations were similar for the two diagnostic groups, although stronger for those with mental disorders. Conclusion Frequent insomnia symptoms dominate the joint association of sleep duration and insomnia symptoms with subsequent disability retirement. Examining exclusively sleep duration would provide an incomplete understanding of the consequences of poor sleep. by Haaramo P, Rahkonen O, Lahelma E, Lallukka T. doi:10.5271/sjweh.3268

With long hours of work, might depression then lurk? A nationwide prospective follow-up study among Danish senior medical consultants

Tue, 10 Jan 2012 18:14:31 +0200

Objective The aim of this study was to examine depression as a potential health effect of long work hours, anticipating an exposure�response relationship. Method A nationwide prospective cohort study of 2790 Danish senior medical consultants was conducted (61.7% response rate). With the consent of the Danish Data Protection Agency, data from a questionnaire survey was linked with data from the Medical Products Agency. Long work hours were defined based on a self-reported average of weekly work hours >40, while redemption of anti-depressive (AD) drug prescriptions defined depression. Proportional hazards Cox regression analyses were conducted adjusting for gender, age, marital status, medical specialty, decision authority at work, work social support, quantitative work demands, and AD drugs prescribed before baseline. Results Long weekly work hours did not increase the risk of redeeming AD drug prescriptions at all times during follow-up compared to the reference of 37�40 work hours [41�44 hours: HR 0.95, 95% confidence interval (95% CI) 0.5�1.8; 45�49 hours: HR 0.88, 95% CI 0.4�1.8; 50�54 hours: HR 0.83, 95% CI 0.3�2.1; 55�59 hours: HR 0.67, 95% CI 0.2�2.9; ≥60 hours: HR 0.48, 95% CI 0.1�3.7]. The same result emerged when work hours was applied in a continuous form (from 25�36 hours to 37�40 hours to 41�44 hours and so on) (HR 0.93, 95% CI 0.76�1.13). Conclusions This study does not support the anticipation that long work hours increase the risk of depression. If anything, long work hours vaguely appeared to decrease the risk of redeeming AD drug prescriptions. by Varma A, Marott JL, Stoltenberg CDG, Wieclaw J, Kolstad HA, Bonde JPE. doi:10.5271/sjweh.3267

The relationship between current and former shift work and the metabolic syndrome

Mon, 09 Jan 2012 17:46:23 +0200

Objective The occurrence of possible health hazards among former shift workers is not well-known. We studied associations of former and current shift work with the metabolic syndrome (MetS). Methods Participants were 1811 full-time employees of a large airline company (1009 men). Working times were categorized into five groups: day worker [N=297 (the reference group)], former shift worker (N=341), 2-shift worker (N=418), night-shift worker (N=283), and in-flight worker (N=472). MetS was measured by the International Diabetes Federation (IDF) criteria and the National Institute of Health Adult Treatment Panel III (NCEP) guideline. The prevalence of the syndrome in the study population was 28.5% and 20.8%, respectively. Results Among male former shift workers, MetS was more prevalent compared to male day workers [IDF: age-adjusted odds ratio (OR) 2.13, 95% confidence interval (95% CI) 1.35�3.37; NCEP: OR 1.83, 95% CI 1.13�2.96]. Associations did not change after additional adjustments for education, smoking, physical activity, alcohol consumption, and insomnia symptoms (IDF: OR 2.00, 95% CI 1.26�3.19; NCEP: 1.67, 95% CI 1.02�2.72). Male 2-shift workers also had an elevated risk of IDF-defined MetS (OR 1.64, 95% CI 1.06�2.55) but the association weakened in the fully adjusted analyses (OR 1.48, 95% CI 0.93�2.24). Prevalence of the MetS was marginally significantly higher among night-shift work (IDF: OR 1.51, 95% CI 0.95�2.34) and was attenuated further with additional adjustments (OR 1.37, 95% CI 0.84�2.22). Among women, no significant differences in prevalence of the MetS between day work and shift work were observed. Conclusion Findings of the cross-sectional study suggest that MetS diagnosed by standardized criteria is more prevalent among former male shift workers than current day workers who have never worked in shifts. by Puttonen S, Viitasalo K, H�rm� M. doi:10.5271/sjweh.3266

The placebo effect revisited

Tue, 20 Dec 2011 20:00:09 +0200

Andersen et al (1) recently published data from a study on brief daily exercise and headache. They reported that a 10-week intervention with 2 minutes of daily exercise using an elastic tube caused a decrease in headache frequency from 1.4 to 0.9 days per week, a 40 % reduction. Very similar results were found for 12 minutes of daily exercise, but not in a control group. No decrease was seen in intensity of headache. A biological background for such a remarkable effect of 10 minutes of training per week does not seem very plausible to us. The authors did not discuss alternative explanations of their findings, for example a placebo effect. In another paper about the same intervention, the authors found that 2 minutes of daily exercise reduced neck/shoulder pain intensity with 1.4 scores on a visual analog scale (VAS) of 0�10 (2) and stated that an effect of this size exceeds the expected effect in response to placebo. The effect size (standardized mean difference) for placebo effects on pain has been shown to be around 0.3 (5) and 0.5 (3) in general, and around 0.8 in 3-armed trials (3). The effect size of 2 and 12 minutes of daily exercise on shoulder/neck pain was approximately 0.5 in the study by Andersen et al (2). However, reported placebo effect sizes vary quite a lot between studies (2, 3). Average placebo effects, therefore, may not apply to a specific study. Each study should be scrutinized for potential placebo effects specific to that study. Expectations are an important factor for placebo effects (4). In the 3-armed trial by Andersen et al, the control group would have no expectations, but the two treatment groups were prone to expectations. Furthermore, larger effects of placebo were found in studies of physical interventions and studies where the outcome was based on participant reporting and cooperation (5). by Andersen JH, Mikkelsen S. doi:10.5271/sjweh.3265

Occupational exposure to endocrine-disrupting chemicals and the risk of uveal melanoma

Sat, 17 Dec 2011 00:10:39 +0200

Objectives We investigated the association between occupational exposure to endocrine-disrupting chemicals (EDC) and the risk of uveal melanoma using international data of a case�control study from nine European countries. Methods After exclusion of proxy interviews, 280 cases and 3084 control subjects were included in the final analysis. Information on possible exposure to EDC was derived from 27 job-specific questionnaires (JSQ), which solicited detailed questions on occupational tasks. Relative risk estimates were based on the JSQ and potential exposure to a group of endocrine-disrupting agents. We constructed several exposure scores, taking into account intensity of exposure, use of personal protective equipment, and exposure duration. We calculated unconditional logistic regression analyses, adjusting for country, age, sex, eye color and a history of ocular damage due to intense ultraviolet (UV) exposure. Results The overall exposure prevalence to EDC was low reaching a maximum of 11% for heavy metals with endocrine-disrupting properties. Although working in some industries was associated with increased melanoma risk [such as dry cleaning: odds ratio (OR) 6.15, 95% confidence interval (95% CI) 2.0�18.96 and working in the glass manufacturing industry: OR 3.49, 95% CI 1.10�11.10], agent-specific risks were not elevated. The strongest possible risk increase was observed for organic solvents with endocrine-disrupting properties (OR 1.31, 95% CI 0.78�2.21). Calculation of exposure scores did not indicate consistently elevated results with higher score values. Sensitivity analyses did not alter these results. Conclusion Occupational exposure to EDC was not associated with an increased risk for uveal melanoma. by Behrens T, Lynge E, Cree I, Lutz J-M, Eriksson M, Gu�nel P, Merletti F, Morales-Suarez-Varela M, Afonso N, Stengrevics A, Stang A, F�votte J, Sabroe S, Llopis-Gonz�lez A, Gorini G, Hardell L, Ahrens W. doi:10.5271/sjweh.3264

Health risk behaviors and morbidity among hospital staff − comparison across hospital ward medical specialties in a study of 21 Finnish hospitals

Thu, 15 Dec 2011 18:01:11 +0200

Objective This study examined whether indicators of poor health and health risk behaviors among hospital staff differ between the ward specialties. Methods Across 21 hospitals in Finland, 8003 employees (mean age 42 years, 87% women, 86% nurses) working in internal medicine, surgery, obstetrics and gynecology, pediatrics, intensive care, and psychiatry responded to a baseline survey on health and health risk behaviors (response rate 70%). Responses were linked to records of sickness absence and medication over the following 12 months. Results Psychiatric staff had higher odds of smoking [odds ratio (OR) 2.58, 95% confidence interval (95% CI) 2.14�3.12], high alcohol use (OR 1.55, 95% CI 1.21�1.99), physical inactivity (OR 1.30, 95% CI 1.11�1.53), chronic physical disease (OR 1.19, 95% CI 1.04�1.36), current or past mental disorders (OR 1.81, 95% CI 1.50�2.17), and co-occurring poor health indicators (OR 2.65, 95% CI 2.08�3.37) as compared to those working in other specialties. They also had higher odds of sickness absence due to mental disorders (OR 1.40, 95% CI 1.02�1.92) and depression (OR 1.61, 95% CI 1.02�2.55) at follow-up after adjustment for baseline health and covariates. Personnel in surgery had the lowest probability of morbidity. No major differences between specialties were found in the use of psychotropic medication. Conclusion The prevalence of hospital employees with an adverse health risk profile is higher in psychiatric wards than other specialties. by Virtanen M, Vahtera J, Batty GD, Tuisku K, Oksanen T, Elovainio M, Ahola K, Pentti J, Salo P, Vartti A-M, Kivim�ki M. doi:10.5271/sjweh.3263

Tossing and turning � insomnia in relation to occupational stress, rumination, fatigue and well-being

Fri, 02 Dec 2011 18:33:59 +0200

Objectives This study of a large and heterogeneous sample of 5210 daytime employees was designed to shed more light on the work effort�recovery mechanism by examining the cross-sectional relations between subjective sleep quality and (i) psychosocial work characteristics, (ii) work-related rumination, (iii) fatigue after work, and (iv) affective well-being at work and work pleasure. Methods We used the Dutch Questionnaire on the Experience and Evaluation of Work and created three sleep quality groups (low, low-to-intermediate, and high quality). Group differences were studied through analysis of variance (ANOVA). To examine the relations among the study variables in more detail, we also conducted four sets of stepwise regression analyses. In all the analyses, we corrected for age, level of education, and gender. Results A series of (M)ANOVA provided strong evidence for a relation between sleep quality and adverse work characteristics and work-related rumination. Furthermore, poor sleepers reported higher levels of fatigue after work, and poor sleep quality was related to both lower affective well-being during work and work pleasure. Regression analyses revealed that sleep quality was the strongest statistical predictor of after-work fatigue and affective well-being at work, and high levels of work rumination constituted the strongest statistical predictor of sleep complaints. Conclusions As this study showed strong relations between sleep quality, occupational stress, fatigue, perseverative cognitions, and work motivation, it supports effort�recovery theory. Interventions should aim to prevent a disbalance between effort and recovery. by Kompier MAJ, Taris TW, van Veldhoven M. doi:10.5271/sjweh.3262

A case-crossover study of work-related acute traumatic hand injuries in the People�s Republic of China

Wed, 23 Nov 2011 18:22:54 +0200

Objective The aim is this study was to quantify potential transient risk factors for occupational acute hand injury among hospitalized workers in the People�s Republic of China (PRC). Methods Participants were recruited from 11 medical facilities in 3 cities of the PRC. A face-to-face interview was used to collect information on the occurrence of 8 potential risk factors within a 90-minute time period before an acute traumatic hand injury and during a control period within the month before the injury. The reliability of reporting transient risk factors was assessed, and a case-crossover design was used to estimate the injury incidence risk ratio (IRR) of each risk factor. Results In total,703 hospitalized workers completed the interview (527 male, 176 female), with a mean age of 31.8 [standard deviation (SD) 10.3] years. The median time interval between injury and interview was four days. Thirty percent of participants had a crush injury and 25.7% had an amputation. Using malfunctioning machinery/tools/material, performing a task with a different method, working overtime, and wearing gloves were found to have good reliability in test-retest examination [intra-class correlation coefficient (ICC)>0.9]. The IRR of a hand injury were markedly increased while using malfunctioning machinery/tools/material [110.4, 95% confidence interval (95% CI) 97.4�125.2], performing a task with a different method than usual (84.3, 95% CI 67.7�105.1), or being distracted (69.6, 95% CI 57.9�83.7). Gender and size of company were associated with differences in glove usage. Conclusions The results suggest the importance of transient, potentially modifiable factors in the etiology of occupational acute hand injury in the PRC. Regular maintenance of machinery/tools, work practice controls, and avoiding distractions should be priorities for reducing the risk of occupational acute hand injuries. by Jin K, Lombardi DA, Courtney TK, Sorock GS, Li M, Pan R, Wang X, Lin J, Liang Y, Perry MJ. doi:10.5271/sjweh.3260

Effect of individualized worksite exercise training on aerobic capacity and muscle strength among construction workers � a randomized controlled intervention study

Fri, 04 Nov 2011 18:53:30 +0200

Objectives The combination of high physical work demands and low physical capacity has been shown to increase the risk for cardiovascular disease and musculoskeletal disorders. The aim of this study was to assess the physical capacity of construction workers and evaluate the effect of individually tailored exercise programs on their physical fitness and muscular capacity. Method The study was a randomized controlled trial of male constructions workers allocated to either an exercise or control group. The intervention lasted 12 weeks, and the exercise group trained 3 x 20 minutes a week. The participants completed health checks before and after the intervention period. Data from the first health check were used to tailor the exercise in the interventions. Results At baseline, participants had maximal oxygen consumption (VO_2max) of 2.9 [standard deviation (SD) 0.7L/min] and body mass index (BMI) of 28.3 (SD 4.7). Compared to representative data on employees in Denmark (N=78), this study population (N=67) had significantly lower relative aerobic capacity [difference in z-score -1.13 (SE 0.1), P<0.001] and higher BMI [difference in z-score 1.10 SE 0.2, P<0.001] at baseline. With respect to the intervention, group x time analyses showed a significant difference in estimated change in VO_2max of 0.4 L/min for the exercise group and 0.0 L/min for the control group (P<0.001). Body mass and other general health measures remained unchanged. Conclusion Training for 20 minutes, 3 times a week significantly increased VO_2max with a clinically relevant magnitude regarding risk of cardiometabolic disorders. This study demonstrates a good effectiveness for integrating short exercise bouts into organizational routines among constructions workers. by Gram B, Holtermann A, S�gaard K, Sj�gaard G. doi:10.5271/sjweh.3259

A systematic review of the effectiveness of occupational health and safety training

Tue, 01 Nov 2011 19:03:23 +0200

Objectives Training is regarded as an important component of occupational health and safety (OHS) programs. This paper primarily addresses whether OHS training has a beneficial effect on workers. The paper also examines whether higher engagement OHS training has a greater effect than lower engagement training. Methods Ten bibliographic databases were searched for pre-post randomized trial studies published in journals between 1996 and November 2007. Training interventions were included if they were delivered to workers and were concerned with primary prevention of occupational illness or injury. The methodological quality of each relevant study was assessed and data was extracted. The impacts of OHS training in each study were summarized by calculating the standardized mean differences. The strength of the evidence on training�s effectiveness was assessed for (i) knowledge, (ii) attitudes and beliefs, (iIi) behaviors, and (iv) health using the US Centers for Disease Control and Prevention�s Guide to Community Preventive Services, a qualitative evidence synthesis method. Results Twenty-two studies met the relevance criteria of the review. They involved a variety of study populations, occupational hazards, and types of training. Strong evidence was found for the effectiveness of training on worker OHS behaviors, but insufficient evidence was found of its effectiveness on health (ie, symptoms, injuries, illnesses). Conclusions The review team recommends that workplaces continue to deliver OHS training to employees because training positively affects worker practices. However, large impacts of training on health cannot be expected, based on research evidence. by Robson LS, Stephenson CM, Schulte PA, Amick BC III, Irvin EL, Eggerth DE, Chan S, Bielecky AR, Wang AM, Heidotting TL, Peters RH, Clarke JA, Cullen K, Rotunda CJ, Grubb PL. doi:10.5271/sjweh.3258

Return to work after early part-time sick leave due to musculoskeletal disorders: a randomized controlled trial

Thu, 27 Oct 2011 18:28:43 +0200

Objectives The purpose of this study was to assess the effects of early part-time sick leave on return to work (RTW) and sickness absence among patients with musculoskeletal disorders. Methods A randomized controlled trial was conducted in six occupational health units of medium- and large-size enterprises. Patients aged 18�60 years with musculoskeletal disorders (N=63) unable to perform their regular work were randomly allocated to part- or full-time sick leave. In the former group, workload was reduced by restricting work time by about a half. Remaining work tasks were modified when necessary, as specified in a �fit note� from the physician. The main outcomes were time to return to regular work activities and sickness absence during 12-month follow-up. Results Time to return to work sustained for ≥4 weeks was shorter in the intervention group (median 12 versus 20 days, P=0.10). Hazard ratio of RTW adjusted for age was 1.60 [95% confidence interval (95% CI) 0.98�2.63] and 1.76 (95% CI 1.21�2.56) after further adjustment for pain interference with sleep and previous sickness absence at baseline. Total sickness absence during the 12-month follow-up was about 20% lower in the intervention than the control group. Compliance with the intervention was high with no discontinuations of part-time sick leave due to musculoskeletal reasons. Conclusions Early part-time sick leave may provide a faster and more sustainable return to regular duties than full-time sick leave among patients with musculoskeletal disorders. This is the first study to show that work participation can be safely increased with early part-time sick leave. by Viikari-Juntura E, Kausto J, Shiri R, Kaila-Kangas L, Takala E-P, Karppinen J, Miranda H, Luukkonen R, Martimo K-P. doi:10.5271/sjweh.3257

Meta-synthesis of qualitative research on return to work among employees with common mental disorders

Mon, 24 Oct 2011 23:55:37 +0200

Objectives The purpose of this study was to investigate which opportunities and obstacles employees with common mental disorders (CMD) experience in relation to return to work (RTW) and how they perceive the process of returning to work. In addition, the study explores what characterizes an optimal RTW intervention and points to possible ways to improve future interventions for employees with CMD. Methods A systematic literature search was conducted, and eight qualitative studies of medium or high quality published between 1995�2011 were included in this systematic review. The eight studies were synthesized using the meta-ethnographic method. Results This meta-synthesis found that employees with CMD identify a number of obstacles to and facilitators of returning to work related to their own personality, social support at the workplace, and the social and rehabilitation systems. The employees found it difficult to decide when they were ready to resume work and experienced difficulties implementing RTW solutions at the workplace. Conclusions This study reveals that the RTW process should be seen as a continuous and coherent one where experiences of the past and present and anticipation of the future are dynamically interrelated and affect the success or failure of RTW. The meta-synthesis also illuminates insufficient coordination between the social and rehabilitation systems and suggests how an optimal RTW intervention could be designed. by Andersen MF, Nielsen KM, Brinkmann S. doi:10.5271/sjweh.3256

Burned out cognition � cognitive functioning of burnout patients before and after a period with psychological treatment

Mon, 24 Oct 2011 20:10:14 +0200

Objectives Many employees with burnout report cognitive difficulties. However, the relation between burnout and cognitive functioning has hardly been empirically validated. Moreover, it is unknown whether the putative cognitive deficits in burnout are temporary or permanent. Therefore, the purpose of the study was to answer two related questions: (i) Is burnout associated with self-reported cognitive difficulties and with deficits in a specific and well-defined set of executive functions? (ii) Do these putative self-reported cognitive difficulties and deficits in executive functioning in burnout diminish after a 10-week period of cognitive behavioral therapy? Methods Sixteen employees with burnout were compared with sixteen matched healthy employees on self-reported cognitive difficulties and tests measuring the basic executive functions, namely, updating, inhibition, and switching, on two test occasions. The interval between the test occasions was ten weeks, during which the burnout individuals received cognitive behavioral therapy. Results On the first test occasion, and relative to healthy individuals, individuals with burnout reported more cognitive difficulties and showed deficits in the �updating� function. No group differences were found regarding the �inhibition� and �switching� functions, although individuals with burnout generally responded slower than healthy individuals on the latter test. Even though after the ten-week treatment period individuals with burnout revealed positive changes regarding burnout symptoms, general health, and self-reported cognitive difficulties, no evidence was found for improved cognitive test performance. Conclusions These findings suggest that either (i) burnout leads to permanent cognitive deficits, (ii) subjective burnout complaints reduce faster than deficits in cognitive test performance, or (iii) cognitive deficits are a cause rather than a consequence of burnout. by Oosterholt BG, Van der Linden D, Maes JHR, Verbraak MJPM, Kompier MAJ. doi:10.5271/sjweh.3201

Synthesizing study results in a systematic review

Fri, 21 Oct 2011 03:01:06 +0200

A single study rarely suffices to underpin treatment or policy decisions. This creates a strong imperative for systematic reviews. Authors of reviews need a method to synthesize the results of several studies, regardless of whether or which statistical method is used. In this article, we provide arguments for combining studies in a review. To combine studies authors should judge the similarity of studies. This judgement should be based on the working mechanism of the intervention or exposure. It should also be assessed if this mechanism is similar for various populations and follow-up times. The same judgement applies to the control interventions. Similar studies can be combined in either a meta-analysis or narrative synthesis. Other methods such as vote counting, levels of evidence synthesis, or best evidence synthesis are better avoided because they may produce biased results. We support our arguments by re-analysing a systematic review. In its original form, the review showed strong evidence of no effect, but our re-analysis concluded there is evidence of an effect. We provide a flow-chart to guide authors through the synthesis and assessment process. by Verbeek J, Ruotsalainen J, Hoving JL. doi:10.5271/sjweh.3199

Breast cancer survivors� views of factors that influence the return-to-work process � a qualitative study

Mon, 10 Oct 2011 18:26:27 +0200

Objectives Accumulating evidence suggests that most employed breast cancer survivors are able to return to work but often experience difficulties in the process. The objective of this study was to identify: (i) factors experienced as barriers to and facilitators of the return-to-work (RTW) process, (ii) which factors were important during initial and post RTW, and (iii) possible solutions to RTW problems. Methods Twelve breast cancer survivors participated in semi-structured interviews. Interviews were thematically analyzed using MAXQDA, software for qualitative data analysis. We used the World Health Organization�s International Classification of Functioning, Disability and Health as a conceptual framework. Results Participants experienced many barriers to and facilitators of RTW. In line with previous studies, we found that work environmental factors, such as support from a supervisor, importance of work, and physical or psychological side-effects (such as fatigability), influenced RTW. In addition, we found that barriers included temperament and personality functions, �job lock�, and societal attitudes, while facilitators comprised taking care of one�s health, skills/coping, and support from family and healthcare professionals. During the initial RTW phase, physical or psychological side-effects hampered work resumption, while during the post RTW phase, a lack of understanding from the work environment was problematic. Participants mentioned that guidance from healthcare professionals and information for supervisors and colleagues should be improved. Conclusions To enhance RTW among breast cancer survivors, interventions should focus on barriers and facilitators for individuals at different time points in the RTW process. Better guidance from healthcare professionals and information for supervisors and colleagues could also enhance the process. by Tamminga SJ, de Boer AGEM, Verbeek JHAM, Frings-Dresen MHW. doi:10.5271/sjweh.3197

Heart rate variability and endothelial function after sleep deprivation and recovery sleep among male shift and non-shift workers

Tue, 27 Sep 2011 22:13:56 +0200

Objectives Endothelial dysfunction and alterations in heart rate variability (HRV) as well as sleep deprivation and shift work have been associated with cardiovascular disease. The aim of this study was to compare HRV and endothelial function among shift and matched non-shift workers in response to total sleep deprivation and recovery sleep under identical laboratory settings. Methods Eleven experienced male shift workers (shift work ≥5 years) and 14 non-shift workers were matched for age, body mass index, and cholesterol. HRV parameters [eg, HR variance and low frequency/high frequency (LF/HF) ratio] were derived from 5-minute electrocardiogram bins at 0.25, 4.25, 11.5, 12.5, and 13.5 hours after habitual wake-up time and endothelial function was assessed by flow-mediated dilatation (FMD) using ultrasound at 0.75 and 10.75 hours after habitual wake-up time, following baseline sleep, total sleep deprivation, and recovery sleep (posture- and food-controlled throughout). Circadian phase was assessed before baseline sleep by salivary dim light melatonin onset. Results There was no difference in circadian phase between shift and non-shift workers. HR variance was highest at 0.25 hours following total sleep deprivation and lowest after recovery sleep. A significantly higher LF/HF ratio, significantly lower HR variance, and a trend for a lower %FMD (P=0.08) were observed among shift compared to non-shift workers. Conclusion Despite similar demographics, circadian phase, posture and food intake, differences in endothelial function and HRV were observed in the two groups, which may reflect higher sympathetic and/or lower parasympathetic activity, contributing to increased cardiovascular risk among the shift workers. by Wehrens SMT, Hampton SM, Skene DJ. doi:10.5271/sjweh.3196

Is peak exposure to computer use a risk factor for neck and upper-extremity symptoms?

Mon, 19 Sep 2011 17:23:28 +0200

Objectives Epidemiologic studies on physical exposure during computer use have mainly focused on average exposure duration. In this study, we aimed to relate periods of high peak exposure during computer use with the occurrence of neck�shoulder (NS) and arm�wrist�hand (AWH) symptoms. Methods A prospective cohort study among 1951 office workers was carried out for two years, with periodical questionnaires and continuous measurements of computer input use. To define peak exposure, a distinction was made between peak days and weeks. Peak days were defined as days with a long duration of computer (ie, ≥4 hours) or mouse use (ie, ≥2.5 hours) or days with high frequency of mouse (ie, ≥20 clicks per minute) or keyboard use (ie, ≥160 keystrokes per minute). Weeks containing ≥3 peak days were considered peak weeks. Independent variables were numbers of peak days and peak weeks during a 3-month measurement period; dependent variables were self-reported NS and AWH symptoms during the following 3-month measurement period. Results Valid data were available for 2116 measurements of 774 office workers. No relation was found between any of the peak exposure parameters and AWH symptoms or with peak exposure in duration and NS symptoms. Most parameters referring to high frequency-related peak exposure were associated with less NS symptoms, but the effect estimates were very small and the confidence intervals close to the null. Conclusion In this study, we found no indication that high peaks in computer use were related to the occurrence of NS or AWH symptoms. by Richter JM, van den Heuvel SG, Huysmans MA, van der Beek AJ, Blatter BM. doi:10.5271/sjweh.3195

Governmental regulations for early retirement by means of energy expenditure cut offs

Wed, 14 Sep 2011 21:05:03 +0200

Objectives Long-term heavy work impairs employees, and they may retire prematurely by law. We investigated the value of energy expenditure (EE) during work shifts as a means to define heavy workload. Methods The study comprised 79 male [mean age 32.2 (standard deviation [SD] 7.5) years] and 33 female [33.5 (SD 11.2) years] employees in different occupations classified as "heavy work" (EE of 1400 and 2000 kcal for women and men, respectively). Cycle ergometry determined exercise performance. Gas exchange measures were performed during selected phases of work, and heart rate (HR) recordings were obtained for a complete work shift. EE was calculated from gas exchange measures. Results Male and female subjects differed significantly for maximal power output (P_max) [men=206.3 (SD 47.3) watts; women=149.6 (SD 36.1) watts] and maximal oxygen consumption (VO_2max) [men=2.965 (SD 0.63) l/min; women= 1.958 (SD 0.50) l/min] in the cycle ergometer test. Shift HR (HR_Sh) was found between 102 (SD 14) b/min [57.6 (SD 8.5) % HR_max] and 99 (SD 10) b/min [55.5 (SD 5.9) % HR_max] dependent on tasks and groups. Working EE was found between 1864 (SD 732) kcal and 1249 (SD 609) kcal for men and women, respectively, but approximately 60% of subjects were well below the legal limits. Conclusions The legal definition of heavy workload by mean working EE per 8-hour work shift applies to all investigated occupations; however, a substantial proportion of workers may not fulfill the criterion if applied individually. Alternative definitions of heavy workload in terms of absolute oxygen consumption or EE relative to cardiorespiratory fitness lead to similar classification results of the investigated occupations. by Wultsch G, Rinnerhofer S, Tschakert G, Hofmann P. doi:10.5271/sjweh.3192

Sensitization and chronic beryllium disease at a primary manufacturing facility, part 3: exposure�response among short-term workers

Mon, 29 Aug 2011 19:56:23 +0200

Objectives Exposure�response relations for beryllium sensitization (BeS) and chronic beryllium disease (CBD) using aerosol mass concentration have been inconsistent, although process-related risks found in most studies suggest that exposure-dependent risks exist. We examined exposure�response relations using personal exposure estimates in a beryllium worker cohort with limited work tenure to minimize exposure misclassification. Methods The population comprised workers employed in 1999 with six years or less tenure. Each completed a work history questionnaire and was evaluated for immunological sensitization and CBD. A job-exposure matrix was combined with work histories to create individual estimates of average, cumulative, and highest-job-worked exposure for total, respirable, and submicron beryllium mass concentrations. We obtained odds ratios from logistic regression models for exposure�response relations, and evaluated process-related risks. Results Participation was 90.7% (264/291 eligible). Sensitization prevalence was 9.8% (26/264), with 6 sensitized also diagnosed with CBD (2.3%, 6/264). A general pattern of increasing sensitization prevalence was observed as exposure quartile increased. Both total and respirable beryllium mass concentration estimates were positively associated with sensitization (average and highest job), and CBD (cumulative). Increased sensitization prevalence was identified in metal/oxide production, alloy melting and casting, and maintenance, and for CBD in melting and casting. Lower sensitization prevalence was observed in plant-area administrative work. Conclusions Sensitization was associated with average and highest job exposures, and CBD was associated with cumulative exposure. Both total and respirable mass concentrations were relevant predictors of risk. New process-related risks were identified in melting and casting and maintenance. by Schuler CR, Virji MA, Deubner DC, Stanton ML, Stefaniak AB, Day GA, Park JY, Kent MS, Sparks R, Kathleen K. doi:10.5271/sjweh.3188

Sensitization and chronic beryllium disease at a primary manufacturing facility, part 1: historical exposure reconstruction

Wed, 17 Aug 2011 15:19:45 +0200

Objectives Previous epidemiologic studies of beryllium sensitization (BeS) and chronic beryllium disease (CBD) have reported inconsistent exposure�response relationships, likely due to exposure misclassification. The objective of this study was to develop historical estimates of size-selective personal exposure to beryllium for an epidemiologic study. Methods In 1999, a cross-sectional survey of workers hired after 1 January 1994 was conducted at a beryllium production facility. Personal exposure data from two air sampling surveys conducted in 1999 were used to obtain total, respirable, and submicron particle baseline exposure estimates (BEE) for a job-exposure matrix (JEM). General area air samples collected from 1994�1999 were used to estimate annual changes in exposures (temporal factors) for 24 different process areas. Historical exposure estimates (HEE) were calculated by applying the temporal factors to the BEE. Workers were assigned HEE based on their work history, and their historical exposure profile was summarized as cumulative, average, or highest-ever job exposure. Results Changes in exposure over a 6-year period were observed in 10 of the 24 process areas with an overall mean decline of 18% per year. The overall total exposure for study participants over their work tenure ranged from: 0.001�34.44 μg/m³-year, 0.01�16.26 μg/m³, and 0.01�17.54 μg /m³ for cumulative, average, and highest-ever job, respectively. For respirable exposures, the ranges were: 0.001�15.54 μg/m³-year, 0.01�3.56 μg/m³, 0.01�5.54 μg /m³ for cumulative, average, and highest-ever job, respectively. Conclusions Using this JEM, exposure�response relationships for BeS and CBD can be explored over a range of exposure metrics such as total, respirable, and submicron beryllium mass concentrations, including summary measures such as cumulative, average, or highest exposures, with the ultimate objective of elucidating a quantitative exposure�response relationship. by Virji MA, Park JY, Stefaniak AB, Stanton ML, Day GA, Kent MS, Kreiss K, Schuler CR. doi:10.5271/sjweh.3187

Sensitization and chronic beryllium disease at a primary manufacturing facility, part 2: validation of historical exposures

Wed, 17 Aug 2011 02:02:57 +0200

Objective The aim of this study was to evaluate the validity of a job exposure matrix (JEM) constructed for the period 1994�1999. Historical exposure estimates (HEE) for the JEM were constructed for all job and year combinations by applying temporal factors reflecting annual change in area air measurements (1994�1998) to the personal baseline exposure estimates (BEE) collected in 1999. The JEM was generated for an epidemiologic study to examine quantitative exposure�response relationships with sensitization and chronic beryllium disease. Methods The validity of the BEE and HEE was evaluated by comparing them with a validation dataset of independently collected personal beryllium exposure measurements from 1999 and 1994�1998, respectively. Agreement between the JEM and validation data was assessed using relative bias and concordance correlation coefficients (CCC). Results The BEE and HEE overestimated the measured exposures in their respective validation datasets by 8% and 6%, respectively. The CCC reflecting the deviation of the fitted line from the concordance line, showed good agreement for both BEE (CCC=0.80) and HEE (CCC=0.72). Proportional difference did not change with exposure levels or by process area and year. Overall, the agreement between the JEM and validation estimates (from combined HEE and BEE) was high (CCC=0.77). Conclusions This study demonstrated that the reconstructed beryllium exposures at a manufacturing facility were reliable and can be used in epidemiologic studies. by Park JY, Virji MA, Stefaniak AB, Stanton ML, Day GA, Kent MS, Schuler CR, Kreiss K. doi:10.5271/sjweh.3184

Occupational health and safety among commercial sex workers

Mon, 01 Aug 2011 16:11:06 +0200

The concept of occupational health and safety (OHS) for commercial sex workers has rarely been investigated, perhaps because of the often informal nature of the workplace, the associated stigma, and the frequently illegal nature of the activity. We reviewed the literature on health, occupational risks, and safety among commercial sex workers. Cultural and local variations and commonalities were identified. Dimensions of OHS that emerged included legal and policing risks, risks associated with particular business settings such as streets and brothels, violence from clients, mental health risks and protective factors, alcohol and drug use, repetitive strain injuries, sexually transmissible infections, risks associated with particular classes of clients, issues associated with male and transgender commercial sex workers, and issues of risk reduction that in many cases are associated with lack of agency or control, stigma, and legal barriers. We further discuss the impact and potential of OHS interventions for commercial sex workers. The OHS of commercial sex workers covers a range of domains, some potentially modifiable by OHS programs and workplace safety interventions targeted at this population. We argue that commercial sex work should be considered as an occupation overdue for interventions to reduce workplace risks and enhance worker safety. by Ross MW, Crisp BR, M�nsson S-A, Hawkes S