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OBJECTIVE: The aim of this study was to assess the association between occupational biomechanical exposures and the occurrence of surgical treatment for subacromial impingement syndrome (SIS). METHODS: A cohort of 220 295 male constructions workers who participated in a national occupational health surveillance program (1971-1993) were examined prospectively over a 16-year follow-up period (2001-2016) for surgically treated SIS. Worker job title, smoking status, height, weight, and age were registered on health examination. Job titles were mapped to 21 occupational groups based on tasks and training. A job exposure matrix (JEM) was developed with exposure estimates for each occupational group. Surgical cases were determined through linkage with the Swedish national in- and outpatient registers. Poisson regression was used to assess the relative risks (RR) for each biomechanical exposure. RESULTS: The total incidence rate of surgically treated SIS over the 16-year observation period was 201.1 cases per 100 000 person-years. Increased risk was evident for workers exposed to upper-extremity loading (push/pull/lift) (RR 1.45-2.30), high hand grip force (RR 1.47-2.23), using handheld tools (RR 1.52-2.09), frequent work with hands above shoulders (RR 1.62-2.11), static work (RR 1.77-2.26), and hand-arm vibration (RR 1.78-2.13). There was an increased risk for SIS surgery for all occupational groups (construction trades) compared with white-collar workers (RR 1.56-2.61). CONCLUSIONS: Occupational upper-extremity load and posture exposures were associated with increased risk for surgical treatment of SIS, which underlines the need for reducing workplace exposures and early symptom detection in highly exposed occupational groups.

Objectives This study aimed to investigate whether change from the construction industry to work in other industries at age 45–55 years lowered risks of disability benefits (DB) later in life (60–64 years of age). We hypothesized that risks would be lowered the most among those changing from the heaviest occupations. Methods The study included men employed in the construction industry during 1971–1993. We selected workers from the largest occupational groups in heavy (concrete workers and painters) and less heavy (drivers, electricians and foremen) occupations. The occurrence of DB in 1990–2015 was retrieved from national registers. Regression analyses were used to calculate relative risks (RR) of DB at 60–64 years, comparing those working in other industries to those still in the construction industry at the age of 45, 50 and 55 years. Results Mobility away from the construction industry was related to lowered DB risks at 60–64 years in all selected occupations. Effects were most pronounced among those who, at 55 years of age, worked in an industry other than construction, with significantly reduced RR for DB among concrete workers [RR 0.63, 95% confidence interval (CI) 0.51–0.77], electricians (RR 0.61, 95% CI 0.47–0.77) and foremen (RR 0.78, 95% 0.63–0.96). Conclusions Risks for DB at 60–64 years of age were reduced among those who changed from construction work to other industries. Notable reductions were observed among workers originating from both heavy and less heavy occupations, and future studies should explore other factors, in addition to heavy workload, as motivators for leaving the construction industry.

Purpose Lung cancer, mesothelioma and several lifestyle-associated cancer forms have been reported more common in merchant seafarers. However, few studies reflect recent occupational settings and women seafarers are usually too scarce for meaningful analyses. We conducted a study on cancer incidence between 1985 and 2011 in a Swedish cohort consisting of male and female seafarers. Methods All seafarers in the Swedish Seafarers’ Register with at least one sea service between 1985 and 2011 and a cumulated sea service time of ≥ 30 days (N = 75,745; 64% men, 36% women; 1,245,691 person-years) were linked to the Swedish Cancer Register and followed-up until 31 December 2011. Standardized incidence ratios (SIR) were calculated with the general population as reference. Results There were 4159 cancer cases in total, with 3221 among men and 938 among women. Male seafarers had an increased risk of total cancer (SIR 1.05; 95% CI 1.01–1.09), lung cancer (SIR 1.51; 95% CI 1.35–1.67) and urinary bladder cancer (SIR 1.17; 95% CI 1.02–1.33). Several lifestyle-associated cancer forms were more common in men. Previous work on tankers was associated with leukaemia (SIR 1.41; 95% CI 1.00–1.86). The risk of cancer decreased with a start as a male seafarer after 1985, with a significant trend for total cancer (P P = 0.001) and, for tanker seafarers, leukaemia (P = 0.045). Women seafarers had an increased risk of lung cancer (SIR 1.54; 95% CI 1.23–1.87) but the risk of total cancer was not increased (SIR 0.83; 95% CI 0.78–0.89). Conclusions In this cohort of merchant Swedish seafarers 1985–2011, the risk of total cancer was increased in men but not in women compared to the general population. Lung cancer was increased in both genders. The risk of cancer seems to decrease over the last decades, but better exposure assessments to occupational carcinogens and longer observation times are needed.

Background The aetiology of sarcoidosis is not well established. In previous studies, smoking has been negatively associated with sarcoidosis and there are some indications of an association between exposure to silica dust and sarcoidosis. Aims To study the risk of sarcoidosis in relation to silica dust exposure. Methods A longitudinal cohort of construction workers linked with a registry of Swedish inpatient diagnoses. Workers were designated as exposed or unexposed to silica based on job titles in a job–exposure matrix. The relative risk (RR) was analysed with Poisson regression adjusting for age and smoking. Results We identified 371 cases of sarcoidosis among 297 917 male workers. There was an increased risk of sarcoidosis in the medium- to high-exposure group [RR 1.83 (95% confidence interval {CI} 1.14–2.95)]. A stratified analysis according to smoking showed that ever-smoking workers had an increased risk of sarcoidosis if highly exposed to silica dust [RR 2.44 (95% CI 1.37–4.33)] compared to non-exposed ever-smokers. The risk of non-smokers highly exposed to silica was not significantly increased [RR 1.07 (95% CI 0.72–1.58)] compared to non-exposed non-smokers. Conclusion The study indicates an increased risk of developing sarcoidosis in ever-smoking men exposed to silica.

ObjectivesThe aim was to assess the association between occupational biomechanical exposure and the occurrence of radial nerve entrapment (RNE) in construction workers over a 13-year follow-up period.MethodsA cohort of 229 707 male construction workers who participated in a national occupational health surveillance programme (1971–1993) was examined prospectively (2001–2013) for RNE. Height, weight, age, smoking status and job title (construction trade) were obtained on health examination. RNE case status was defined by surgical release of RNE, with data from the Swedish national registry for out-patient surgery records. A job exposure matrix was developed, and biomechanical exposure estimates were assigned according to job title. Highly correlated exposures were summed into biomechanical exposure scores. Negative binomial models were used to estimate the relative risks (RR) (incidence rate ratios) of RNE surgical release for the biomechanical factors and exposure sum scores. Predicted incidence was assessed for each exposure score modelled as a continuous variable to assess exposure–response relationships.ResultsThe total incidence rate of surgically treated RNE over the 13-year observation period was 3.53 cases per 100 000 person-years. There were 92 cases with occupational information. Increased risk for RNE was seen in workers with elevated hand-grip forces (RR=1.79, 95% CI 0.97 to 3.28) and exposure to hand-arm vibration (RR=1.47, 95% CI 1.08 to 2.00).ConclusionsOccupational exposure to forceful handgrip work and vibration increased the risk for surgical treatment of RNE.

Background: Cigarette smoking and occupational exposures each have been reported to increase the risk of idiopathic pulmonary fibrosis (IPF), a disease previously considered of unknown origin. We investigated the risk of IPF mortality associated with combined smoking and occupational exposures. Methods: A registry study of Swedish construction workers (N = 389,132), linked baseline smoking and occupational data with registry data on cause of death and hospital care diagnoses. Occupation was classified by the likelihood of exposure to vapors, gases, dusts, or fumes using a job-exposure matrix. Those likely exposed to asbestos or silica were excluded from the analysis. Age-adjusted relative risks [RRs] were calculated using Poisson regression. Follow-up observation began at age 40 and ended at age 89. Results: Heavy smokers at baseline who were exposed to inorganic dusts during their working life had an increased risk of IPF mortality (RR 1.70; 95% confidence interval [CI] 1.11–2.60), while there was no statistically increased risk in the other exposure groups. There were dose–response relationships between smoking at baseline and IPF mortality among both unexposed and dust exposed workers, with similar risk for dust exposed and unexposed, except among baseline heavy smokers, where workers exposed to inorganic dust manifested the highest risk (RR 4.22; 95% CI 2.69–6.60). Excluding workers with chronic obstructive pulmonary disease or emphysema did not affect the results substantively. Conclusion: A clear dose–response relationship was seen between smoking at baseline and IPF, supporting a causal relationship. Occupational exposure to inorganic dusts, excluding silica and asbestos, was associated with increased risk of IPF in baseline heavy current smokers.

Purpose Comorbidity indices are often used to measure comorbidities in register-based research. We aimed to adapt the Charlson comorbidity index (CCI) to a Swedish setting. Methods Four versions of the CCI were compared and evaluated by disease-specific experts. Results We created a cohesive coding system for CCI to 1) harmonize the content between different international classification of disease codes (ICD-7,8,9,10), 2) delete incorrect codes, 3) enhance the distinction between mild, moderate or severe disease (and between diabetes with and without end-organ damage), 4) minimize duplication of codes, and 5) briefly explain the meaning of individual codes in writing. Conclusion This work may provide an integrated and efficient coding algorithm for CCI to be used in medical register-based research in Sweden.

Aims: This study investigated mortality in disability pensions due to common mental disorder, and variation over time after first receiving disability pension. Methods: Objectives were explored in 301,863 construction workers (97.2% men) recruited through healthcare examinations from 1971–1993. By linking with the Swedish National Insurance Agency registers, disability pensions until 2014 were identified. Common mental disorder was defined as disability pension diagnosis due to anxiety, stress-related disorders or moderate depression. Mortality was calculated in all-psychiatric diagnosis and diagnostic sub-groups, and compared to persons without disability pensions, using Poisson regression. Additional analyses were stratified by age at follow-up. Results: In total 6030 subjects received disability pensions based on psychiatric diagnoses, and 2624 constituted common mental disorder. Analyses in an all-psychiatric diagnosis displayed increased mortality risks in men (relative risk 3.6; 95% confidence interval 3.3–3.9) and women (relative risk 2.1; 95% confidence interval 1.6–2.6). Common mental disorder was associated with mortality, especially in men (relative risk 2.5; 95% confidence interval 2.2–2.8). Increased relative risks in alcohol and substance abuse were also observed. Results in analyses stratified by age at follow-up displayed persistent high relative risks for mortality in older ages (75–89 years) in men in all-psychiatric disability pensions diagnosis (relative risk 2.8; 95% confidence interval 2.1–3.7) and common mental disorder diagnosis (relative risk 2.6; 95% confidence interval 1.8–3.6), compared to men without disability pensions. Similar results were found in women, but few cases lowered the precision of estimates. Conclusions: This study shows that disability pension based on common mental disorders, often regarded as a ‘lighter’ psychiatric diagnosis, is a risk for early mortality in construction workers, even several years after first receiving disability pension.

Purpose The present study examined a possible association between occupational exposure to noise, working and living in cold conditions, and the risk of mortality in myocardial infarction and stroke. Methods The present cohort study consists of 194,501 workers in the Swedish construction industry that participated in health examinations between 1971 and 1993. Noise exposure was defined on a job-exposure matrix based on a survey of the working conditions carried out during the mid 1970s. All workers were categorised into three main regions of Sweden, differing in temperature: Reference (Götaland), colder (Svealand), and coldest (Norrland). Relative risks (RR) were analysed by negative binomial regression adjusting for age, BMI, and smoking habits. Results Moderate and high noise exposure was associated with increased risk of myocardial infarction (RR 1.10–1.13 with 95% CI over unit) and stroke mortality (RR 1.15 to 1.19 with 95% CI over unit). There was an increased risk for myocardial infarction (RR 1.10, 95% CI 1.01–1.20), but not for stroke mortality (RR 1.09, 95% CI 0.94–1.25) associated with living and working in the coldest region. There was an interaction on the risk of myocardial infarction mortality between different regions and noise exposure (p = 0.016), but not for stroke mortality (p = 0.88). Conclusions The study indicates an interaction between working at hazardous noise levels and living and working in cold conditions for increased mortality in myocardial infarction.

Obesity is a risk factor for advanced, but not localised, prostate cancer (PCa), and for poor prognosis. However, the detection of localised PCa through asymptomatic screening might influence these associations. We investigated height and body mass index (BMI) among 431 902 men in five Swedish cohorts in relation to PCa risk, according to cancer risk category and detection mode, and PCa-specific mortality using Cox regression. Statistical tests were two-sided. Height was positively associated with localised intermediate-risk PCa (HR per 5 cm, 1.03, 95% CI 1.01 to 1.05), while overweight and obesity were negatively associated with localised low- and intermediate-risk PCa (HRs per 5 kg/m2 , 0.86, 95% CI 0.81 to 0.90, and 0.92, 95% CI 0.88 to 0.97). However, these associations were partially driven by PCa's detected by asymptomatic screening and, for height, also by symptoms unrelated to PCa. The HR of localised PCa's, per 5 kg/m2 , was 0.88, 95% CI 0.83 to 0.92 for screen-detected PCa's, and 0.96, 95% CI 0.90 to 1.01 for PCa's detected through lower urinary tract symptoms. BMI was positively associated with PCa-specific mortality in the full population and in case-only analysis of each PCa risk category (HRs per 5 kg/m2 , 95% CI 1.11 to 1.22, P for heterogeneity = 0.14). More active health-seeking behaviour among tall and normal-weight men may partially explain their higher risk of localised PCa. The higher PCa-specific mortality among obese men accros all PCa risk categories in our study suggests obesity as a potential target to improve the prognosis of obese PCa patients.

Tobacco smoking is an injurious habit associated with a number of chronic disorders. Its influence on disc metabolism and degeneration including lumbar spinal stenosis (LSS) has been investigated in the literature.We aimed to investigate whether tobacco smoking is an independent risk factor for undergoing surgical intervention for LSS.This is a prospective cohort study.The patient sample of 331,941 workers was derived from a Swedish nationwide occupational surveillance program for construction workers.The outcome measure included the incidence of undergoing surgical intervention for LSS in tobacco smokers versus no smokers.At inclusion, age, sex, body mass index (BMI), workers' job title, and self-reported smoking habits were registered. The workers were divided into four categories: never smoked, former smoker, moderate current (1-14 cigarettes/day), and heavy current (≥15 cigarettes/day). Patients who underwent a surgically treated LSS were defined using the relevant International Classification of Diseases (ICD) disease code derived from the Swedish National Patient Register.A total of 331,941 participants were included in the analysis. Forty-four percent of the participants were non-smokers, 16% were former smokers, 26% were moderate smokers, and 14% were heavy smokers. The vast majority of construction workers were males (95%). During the average follow-up of 30.7 years, 1,623 participants were surgically treated for LSS. The incidence rate ratio (IRRs) of LSS varied across smoking categories, with the highest values found in heavy smokers. Compared with non-smokers, all smoking categories show an increased incidence of surgically treated LSS. The findings were consistent even when the comparison was performed for participants with BMIs between 18.5 and 25 and for participants aged between 40 and 74 years.Tobacco smoking is associated with an increased incidence of surgically treated LSS. The effect seems to be dose related, whereby heavy smokers have a higher risk than moderate or former smokers.

Background Subarachnoid haemorrhage (SAH) is a devastating disease, with high mortality rate and substantial disability among survivors. Its causes are poorly understood. We aimed to investigate risk factors for SAH using a novel nationwide cohort consortium. Methods We obtained individual participant data of 949 683 persons (330 334 women) between 25 and 90 years old, with no history of SAH at baseline, from 21 population-based cohorts. Outcomes were obtained from the Swedish Patient and Causes of Death Registries. Results During 13 704 959 person-years of follow-up, 2659 cases of first-ever fatal or non-fatal SAH occurred, with an age-standardized incidence rate of 9.0 [95% confidence interval (CI) (7.4–10.6)/100 000 person-years] in men and 13.8 [(11.4–16.2)/100 000 person-years] in women. The incidence rate increased exponentially with higher age. In multivariable-adjusted Poisson models, marked sex interactions for current smoking and body mass index (BMI) were observed. Current smoking conferred a rate ratio (RR) of 2.24 (95% CI 1.95–2.57) in women and 1.62 (1.47–1.79) in men. One standard deviation higher BMI was associated with an RR of 0.86 (0.81–0.92) in women and 1.02 (0.96–1.08) in men. Higher blood pressure and lower education level were also associated with higher risk of SAH. Conclusions The risk of SAH is 45% higher in women than in men, with substantial sex differences in risk factor strengths. In particular, a markedly stronger adverse effect of smoking in women may motivate targeted public health initiatives.

BACKGROUND: Work on Swedish petroleum tankers before the late 1980s has been associated with an increased risk of hematologic malignancy (HM). Since then, ship modernizations have decreased occupational exposure to gases, including the carcinogen benzene. We explored the risk of HMs in Swedish seafarers who had worked on newer types of tankers. METHODS: A case-referent study in male seafarers from a cohort of all Swedish seafarers was set up by record linkage with the Swedish Cancer Registry using the subjects' personal identification number. For each case (N = 315), five referents were randomly chosen from within the cohort, matched by birth year and three different periods of first sea service (Originally included in thesis in manuscript form with the title: "Hematologic malignancy on tankers: A case -referent study among male Swedish seafarers"

OBJECTIVES: The aim of this study was to determine the association between occupational biomechanical exposures and occurrence of surgically treated ulnar nerve entrapment (UNE). METHODS: A cohort of 229 689 male construction workers who participated in a national occupational health surveillance program (1971–1993) were examined prospectively over a 13-year case ascertainment period (2001–2013) for surgically treated UNE. Job title (construction trade), smoking status, height, weight and age were recorded on examination. Job titles were merged into occupational groups of workers performing similar work tasks and having similar training. Occupational biomechanical exposure estimates were assigned to each occupational group with a job exposure matrix (JEM) developed for the study. Negative binomial models were used to assess the relative risks for each biomechanical exposure and the sums of highly correlated biomechanical exposures. Surgical treatment of UNE was determined via a linkage with the Swedish Hospital Outpatient Surgery Register. RESULTS: There were 555 cases of surgically treated UNE within the cohort. Workers exposed to forceful hand-grip factors had a 1.4-fold higher relative risk (95% CI 1.18–1.63) of undergoing surgical treatment for UNE compared to unexposed workers. Occupational groups comprising workers exposed to forceful hand-grip work showed the highest risks for UNE and included concrete workers, floor layers, ground preparatory workers, rock blasters, and sheet-metal workers. CONCLUSION: Forceful hand-grip work increases the risk for surgically treated ulnar nerve entrapment.

Purpose To get knowledge of the work environment for seafarers sailing under the Swedish flag, in terms of safety climate, ergonomical, chemical and psychosocial exposures, and the seafarers self-rated health and work ability. Methods A Web-based questionnaire was sent to all seafarers with a personal e-mail address in the Swedish Maritime Registry (N = 5608). Comparisons were made mainly within the study population, using Student’s t test, prevalence odds ratios and logistic regressions with 95% confidence intervals. Results The response rate was 35% (N = 1972; 10% women, 90% men), with 61% of the respondents working on deck, 31% in the engine room and 7% in the catering/service department (1% not classifiable). Strain on neck, arm or back and heavy lifting were associated with female gender (p = 0.0001) and younger age (below or above 30 years of age, p

Aims: Study objectives were to investigate how changes in social insurance legislation influenced the incidence of disability pension. Methods: The study included 295,636 male construction workers who attended health examinations between 1971 and 1993, aged 20–60 years and without previous disability pension. Via the Swedish National Insurance Agency national register we identified 66,046 subjects who were granted disability pension up until 2010. The incidence rates were calculated and stratified according to age and diagnosis. Results: The incidence rate of disability pension was fairly stable until the 1990s when large variations occurred, followed by a strong decreasing trend from the early 2000s to 2010. Trends in incidence rates, stratified by age and diagnosis, showed a consistent decrease in cardiovascular disease for all age groups. In subjects aged 30–49 years there was a high peak around 2003 for musculoskeletal diseases and psychiatric diseases. For the age group 50–59 years, musculoskeletal diagnosis, the most common cause of disability pension, had a sharp peak around 1993 and then a decreasing trend. In the 60–64 age group, the incidence rate for psychiatric diagnosis was stable, while incidence rates for musculoskeletal diagnosis varied during the 1990s. Conclusions: There are considerable variations in the incidence rate of disability pension over time, with different patterns depending on age and diagnosis. Changes in social insurance legislation, as well as in administration processes, seem to influence the variation.

Objective The aim was to examine if exposure to whole-body vibration (WBV) increases the risk for hospitalization due to lumbar disc herniation. Methods The study basis is a cohort of 288,926 Swedish construction workers who participated in a national occupational health surveillance programme from 1971 until 1992. Job title, smoking habits, body weight, height and age were registered at the examinations. Assessment of WBV were made for each of the constituent occupations by constructing a job-exposure matrix (JEM). Exposure to WBV was graded on a scale from 0 to 5. In addition, the occurrence of hospitalization due to lumbar disc herniation from January 1st 1987 until December 31st 2010 was collected from a linkage with the Swedish Hospital Discharge Register. Poisson regressions were used to estimate relative risk with 95 percent confidence intervals (95% CI), adjusting for age, height, weight and smoking, using white-collar workers and foremen as a reference group. Results There was an increased risk for hospitalization due to lumbar disc herniation for workers in the construction industry exposed to medium to high WBV compared to white-collar workers and foremen 1.35 (1.12–1.63). When restricting the analyses to include workers 30–49 years of age at the time of the hospital admission the risk was 1.69 (95% CI 1.29–2.21). Conclusion This study further supports that occupational exposure to whole-body vibration increases the risk for hospitalization due to lumbar disc herniation. Electronic supplementary material The online version of this article (10.1007/s00420-018-1316-5) contains supplementary material, which is available to authorized users.

The association between occupational exposure and autoimmune disease is well recognized for silica, and suspected for other inhalants. We used a large cohort to estimate the risks of rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis, and dermatomyositis associated with silica and other occupational exposures.We analyzed data for male Swedish construction industry employees. Exposure was defined by a job-exposure matrix for silica and for other inorganic dusts; those with other job-exposure matrix exposures but not to either of the 2 inorganic dust categories were excluded. National hospital treatment data were linked for International Classification of Diseases, 10(th) Revision-coded diagnoses of rheumatoid arthritis (seronegative and positive), systemic lupus erythematosus, systemic sclerosis, and dermatomyositis. The 2 occupational exposures were tested as independent predictors of prospective hospital-based treatment for these diagnoses using age-adjusted Poisson multivariable regression analyses to calculate relative risk (RR).We analyzed hospital-based treatment data (1997 through 2010) for 240,983 men aged 30 to 84 years. There were 713 incident cases of rheumatoid arthritis (467 seropositive, 195 seronegative, 51 not classified) and 128 cases combined for systemic lupus erythematosus, systemic sclerosis, and dermatomyositis. Adjusted for smoking and age, the 2 occupational exposures (silica and other inorganic dusts) were each associated with increased risk of rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis, and dermatomyositis combined: RR 1.39 (95% confidence interval [CI], 1.17-1.64) and RR 1.31 (95% CI, 1.11-1.53), respectively. Among ever smokers, both silica and other inorganic dust exposure were associated with increased risk of rheumatoid arthritis (RRs 1.36; 95% CI, 1.11-1.68 and 1.42; 95% CI, 1.17-1.73, respectively), while among never smokers, neither exposure was associated with statistically significant increased risk of rheumatoid arthritis.This analysis reaffirms the link between occupational silica and a range of autoimmune diseases, while also suggesting that other inorganic dusts may also impart excess risk of such disease.

Objective: To study the risk of lung cancer in heavily asbestos-exposed workers after the exposure to asbestos has ended. Methods: Lung cancer was studied in a cohort of 189,896 Swedish construction workers through a linkage with the Swedish Cancer Registry. Asbestos exposure was estimated by the incidence of malignant mesothelioma in the occupational group. Results: There were in total 2835 cases of lung cancer. Workers with heavy exposure to asbestos had an increased risk of lung cancer (relative risks = 1.74; 95% confidence interval, 1.25 to 2.41) before exposure ended and a similar risk to those with low exposure 20 years after the exposure had ceased (relative risks = 0.94; 95% confidence interval, 0.77 to 1.15). Conclusions: Workers with heavy exposure to asbestos have a similar risk of lung cancer as persons with low or no exposure 20 years after the exposure has ended.

Objectives: The objectives of this study are to investigate the relation between obesity and labour force exit via diagnosis-specific disability benefits, and whether physical workload modifies this association. Methods: A longitudinal analysis was performed among 3 28 743 Swedish construction workers in the age of 15-65 years. Body weight and height were measured at a health examination and enriched with register information on disability benefits up to 37 years later. Diagnoses of disability benefits were categorised into cardiovascular diseases (CVDs), musculoskeletal diseases (MSDs), mental disorders and others. A job exposure matrix, based on self-reported lifting of heavy loads and working in bent forward or twisted position, was applied as a measure of physical workload. Cox proportional hazards regression analyses were performed, and the relative excess risk due to interaction (RERI) between obesity and physical workload was calculated. Results: Obese construction workers were at increased risk of receiving disability benefits (HR 1.70, 95% CI 1.65 to 2.76), mainly through CVD (HR 2.30) and MSD (HR 1.71). Construction workers with a high physical workload were also more likely to receive a disability benefit (HR 2.28, 95% CI 2.21 to 2.34), particularly via MSD (HR 3.02). Obesity in combination with a higher physical workload increased the risk of disability benefits (RERI 0.28) more than the sum of the risks of obesity and higher physical workload, particularly for MSD (RERI 0.44). Conclusions: Obesity and a high physical workload are risk factors for disability benefit. Furthermore, these factors are synergistic risk factors for labour force exit via disability benefit through MSD. Comprehensive programmes that target health promotion to prevent obesity and ergonomic interventions to reduce physical workload are important to facilitate sustained employment.

The objective was to study the epidemiology of fatal occupational injuries in Sweden as a basis for injury mitigation activities. Data of injury incidents from the years 2010–4 registered at the Swedish Working Authority and AFA Insurance was used along with national registers for hospitalised persons combined with national registers of individual data on occupational and industry. We also compared the epidemiology of serious with fatal incidents. On average 50 fatalities happened per year, i.e. around 1 per 1 00 000 persons in the work force. Around two of three fatalities involved a vehicle related incident or a fall from height. There was a weak association between fatal and serious incidents. Codes about occupational factors in hospital diagnoses were very often missing (60%–70%) and linkages between hospital registers, death registers and other medical data registers had limited use to find strategies for prevention. Conclusions Small numbers hampers the possibility to follow trends in fatal occupational incidents. The epidemiology of serious incidents is a rather poor ground for prioritising measures for preventing fatal injuries. Traditional variables in registers of fatal incidents as sex, age, industry and job has limited information for prioritising preventive measures. There are already a lot preventive measures undertaken. However, much more could be done e.g. with focus on vehicle related injuries and falls from high level. We think that an additional prioritising factor in the injury reducing work would be to address how well we know, or can find, suitable preventive strategies should be included.

OBJECTIVE: To investigate whether the decreased use of paints based on organic solvents has caused a decreased risk for neuropsychiatric disorders in painters by studying their incidence in disability pensions. METHODS: The incidence of disability pension in Swedish painters who had participated in health examinations between 1971 and 1993 was studied through linkage with Swedish registers of disability pension over 1971-2010 and compared with the incidence in other construction workers as woodworkers, concrete workers and platers. When phasing out began in the 1970s, about 40% of paints were based on organic solvents and it had decreased to 4% in 1990s. The analysis was adjusted for age, time period, body mass index and smoking. RESULTS: The painters (n=23 065) had an increased risk of disability pension due to neurological diagnosis (n=285, relative risk (RR) 1.92, 95% CI 1.67 to 2.20) and psychiatric diagnosis (n=632, RR=1.61, 95 % CI 1.42 to 1.82). For neurological disorders there was a time trend with a continuously decreasing risk from 1980 onwards, but there was no such trend for psychiatric disorders. CONCLUSIONS: High exposure to organic solvents increased the risk for disability pension in neurological disorders, and the risk decreased when the use of organic solvents decreased. The painters also had an increased risk of disability pension due to psychiatric disorders, but the causes have to be further investigated.

Objective The aim of the present study was to elucidate whether occupational exposure to vapors, gases, dusts, and fumes increases the mortality risk of COPD, especially among never smokers. Methods The study population was a cohort of 354,718 male construction workers; of these, 196,329 were exposed to vapors, gases, dusts, and fumes, and 117,964 were unexposed. Exposure to inorganic dust, wood dust, vapors, fumes, gases, and irritants was based on a job-exposure matrix with a focus on exposure in the mid-1970s. The cohort was followed from 1971 to 2011. Relative risks (RRs) were obtained using Poisson regression models adjusting for age, BMI, and smoking habits. Results There were 1,085 deaths from COPD among the exposed workers, including 49 never smokers. Workers with any occupational exposure to vapors, gases, fumes, and dust showed an increased mortality due to COPD (RR, 1.32; 95% CI, 1.18-1.47). When comparing different exposure groups, there was a significantly increased mortality due to COPD among those exposed to fumes (RR, 1.20; 95% CI, 1.07-1.36) and inorganic dust (RR, 1.19; 95% CI ,1.07-1.33). Among never smokers, there was high mortality due to COPD among workers with any occupational airborne exposure (RR, 2.11; 95% CI, 1.17-3.83). The fraction of COPD attributable to occupational exposure was 0.24 among all workers and 0.53 among never-smoking workers. Conclusions Occupational exposure to airborne pollution increases the mortality risk for COPD, especially among never smokers.

This introductory paper considers the value and limitations of the methodology of systematic reviews especially according to the evidence-based movement. It explains some terms and organisations producing systematic reviews. It also discusses controversies. The first concerns the criteria by which the quality of individual studies is assessed, the second the possible effects of the affiliation of some reviewers, and the third the value of formalisation of procedure (i.e. the tensions between formal tools and professional judgments). The article contrasts the evidence-based formalism with other formalisms as those by the Intergovernmental Panel on Climate Change and the International Agency for Research on Cancer. It discusses systematic reviews in social science where interventions are complex, difficult to blind, and depend on context. Systematic reviews in working life research are often focusing on prevention. The formal evidence-based process may devaluate or disregard findings from mechanistic and observational studies. Hence such reviews may falsely conclude that existing knowledge about the risk of the factor is limited or nonexistent.

OBJECTIVE: To study the occurrence of pleural mesothelioma as a measure of the impact on health from asbestos exposure in the construction industry.METHODS: The occurrence of pleural mesothelioma i ...

The objective of this study was to estimate the mortality from cancer, cardiovascular, and respiratory diseases attributable to occupational exposure in Sweden.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.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.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.

Objectives were to investigate prospectively the ability of DNA adducts to predict cancer and to study the determinants of adducts, especially air pollutants. DNA adducts were measured in a case-control study nested in the European Prospective Investigation into Cancer and Nutrition (EPIC) investigation. Cases included newly diagnosed lung cancer (n = 115), upper respiratory cancers (pharynx and larynx; n = 82), bladder cancer (n = 124), leukemia (n = 166), and chronic obstructive pulmonary disease or emphysema deaths (n = 77) accrued after a median follow-up of 7 years among the EPIC former smokers and never-smokers. Three controls per case were matched for questionnaire analyses and two controls per case for laboratory analyses. Matching criteria were gender, age, smoking status, country of recruitment, and follow-up time. Individual exposure to air pollution was assessed using concentration data from monitoring stations in routine air quality monitoring networks. Leukocyte DNA adducts were analyzed blindly using 32P postlabeling technique. Adducts were associated with the subsequent risk of lung cancer, with an odds ratio (OR) of 1.86 [95% confidence interval (95% CI), 0.88-3.93] when comparing detectable versus nondetectable adducts. The association with lung cancer was stronger in never-smokers (OR, 4.04; 95% CI, 1.06-15.42) and among the younger age groups. After exclusion of the cancers occurring in the first 36 months of follow-up, the OR was 4.16 (95% CI, 1.24-13.88). A positive association was found between DNA adducts and ozone (O3) concentration. Our prospective study suggests that leukocyte DNA adducts may predict lung cancer risk of never-smokers. Besides, the association of DNA adduct levels with O3 indicates a possible role for photochemical smog in determining DNA damage.

Disability pensions due to skin diseases in Swedish male construction workers were studied by linking data from pension registers and an occupational health service. Incidence rates of disability pensions for cement workers, painters and plumbers were compared with 2 control groups. A total of 623 disability pensions were granted during 4 decades of follow-up. The main diagnoses were eczema (36%) and psoriasis (49%). Pensions were mostly granted in the age range 55-64 years. Among painters, cement workers and plumbers the incidence rates for disability pensions were 33.3, 24.5 and 20.4 cases/100,000 person-years, respectively, compared with 13.7 and 9.2 cases/100,000 person-years in control groups. Relative risks were highest for eczema, and were notable for psoriasis. Attributable fractions for eczema were 90% in cement workers and painters and 75% in plumbers compared with control groups. Attributable fractions for psoriasis in the occupational groups studied were in the range 54-67%. In conclusion, eczema and psoriasis have a high impact on loss of work ability, as reflected by disability pensions.

Return to work interventions are usually complex and have a strong dependence on contextual factors such as insurance systems, workplaces, and stakeholders. Mechanistic aspects of the intervention are important and should be developed and studied before efficiency trials are initiated. This likely involves the workplace; for the employer, the productivity of the worker is essential; however, this has been rarely studied, and there are few objective evaluation instruments. Randomization in the evaluation of return to work interventions is desirable in efficiency studies. In reporting such studies, the CONSORT statement for non-pharmacological trials is recommended. The theories and conceptual models behind an intervention should be clearly articulated.

Prospective cohort study.To study biomechanical factors in relation to symptomatic lumbar disc disease.The importance of biomechanical factors in lumbar disc disease has been questioned in the past decade and knowledge from large prospective studies is lacking.The study basis is a cohort of 263,529 Swedish construction workers who participated in a national occupational health surveillance program from 1971 until 1992. The workers' job title, smoking habits, body weight, height, and age were registered at the examinations. The occurrence of hospitalization due to lumbar disc disease from January 1, 1987, until December 31, 2003, was collected from a linkage with the Swedish Hospital Discharge Register.There was an increased risk for hospitalization due to lumbar disc disease for several occupational groups compared with white-collar workers and foremen. Occupational groups with high biomechanical loads had the highest risks, for example, the relative risk for concrete workers was 1.55 (95% confidence interval [CI], 1.29-1.87). A taller stature was consistently associated with an increased risk. The relative risk for a man of 190- to 199-cm height was 1.55 (95% CI, 1.30-1.86) compared with a man being 170- to 179-cm height. Body weight and smoking were also risk factors, but weaker than height. Workers in the age span of 30 to 39 years had the highest relative risk (RR = 1.87; 95% CI, 1.58-2.23) compared with those aged 20 to 29 years, whereas men aged 60 to 65 years had a lower risk (RR = 0.86; 95% CI, 0.68-1.09).This study indicates that factors increasing the load on the lumbar spine are associated with hospitalization for lumbar disc disease. Occupational biomechanical factors seem to be important, and a taller stature was consistently associated with an increased risk.

Many measures have been taken in Sweden to eliminate the occurrence of serious silicosis. However, between 1997 and 2013 there were 111 deaths with silicosis as underlying cause, 110 men and 1 woman. In most cases the deceased was rather old; only fourteen persons were below 74 years of age. We have studied the exposure between 2007 and 2012 in the 71 persons who died of silicosis as underlying or contributing cause through medical records. We could find information regarding 48 of them. Ten persons worked in mines, 10 in stone industry, 14 with crushing or blasting of rock, 4 in foundries, 3 were concrete workers and 7 suffered exposure in other industries. The study shows that the measures taken in Sweden have not been sufficient to totally eliminate serious silicosis.

There are epidemiological studies indicating that exposure to metal fumes is a risk factor for infectious pneumonia. Whether occupational exposure to other agents, such as inorganic dust or chemicals, also increases the risk for infectious pneumonia is not clear. The aim of the present study was to elucidate whether occupational exposure to respiratory pollutants and irritants increases the risk for infectious pneumonia.Prospective cohort study. Setting Swedish male construction workers. Participants 320,143 male construction workers exposed to inorganic dust (asbestos, man-made mineral fibres, dust from cement, concrete and quartz), wood dust, metal fumes and chemicals (organic solvents, diisocyanates and epoxi resins) or unexposed. Main outcome measures The cohort was followed from 1971 to 2003 and the main outcome measures were mortality to infectious pneumonia, lobar pneumonia or pneumococcal pneumonia. RRs were obtained by the person-years method and from Poisson regression models, adjusting for baseline values of age and smoking habits.Among men aged 20-64 years there was increased mortality from infectious pneumonias among construction workers exposed to metal fumes (RR 2.31, 95% CI 1.35 to 3.95), inorganic dust (RR 1.87, 95% CI 1.22 to 2.87) and chemicals (RR 1.91, 95% CI 1.37 to 3.22). The mortality was also increased from both lobar pneumonia and pneumococcal pneumonia. Among men aged 65-84 years the occupational exposure to inorganic dust and chemicals was associated with slightly increased mortality from infectious pneumonia. Among groups with mutually exclusive exposures there was increased mortality from infectious pneumonias among construction workers exposed to inorganic dust, but not among those exposed to wood dust or chemicals. There were no cases among workers exposed only to metal fumes.Our findings indicate that exposure to inorganic dust increases the mortality from infectious pneumonias, especially lobar pneumonia and pneumococcal pneumonia. The mechanism is unclear, but the effect may be mediated through induced airways inflammation.

The decision to award a disability pension includes a formal procedure that varies between countries. Medical doctors are often used as experts in this process, sometimes they also make the final decision. The study by Dell-Kuster et al (1) shows how evaluations can differ among physicians. The judgments between the physicians who treat the patients and a group of specialized physicians differed considerably. The differences reported in the study is probably greater than in a random sample of patients who apply for disability pension as the study includes cases that have been referred for further investigation by a disability insurance officer due to inconsistencies in the assessments. However, the differences raise a question about the validity of judgments and justice – do similar cases have the same evaluation? The criteria for disability pension varies between countries, but it includes an evaluation of the disease and the functional impairments caused by the disease, and also the possibilities to work and get a job despite the impairments. Work is a not a clearly defined subject. You can work in the garden (ie, take care of your roses) but be unable to perform most paid work if your “productivity” is too low for employers’ needs. Many people with diseases work. A Finnish study of public employees around 60 years of age found that 74% had at least one chronic disease (2). Also workers with decreased productivity may work. An average decrease of 34% for productivity was reported among Finnish workers with upper-extremity disorders who were not on sick leave (3). A Dutch study found a considerable loss of productivity a year after workers had returned to work after having being on sick leave for musculoskeletal disorders (4). The possibility to work while having a disease depends on the individual’s possibility to adjust his work. Geuskens et al (5) followed persons with newly onset arthritis during 12 months and found that 39% adapted the work, mainly through changing the work environment or working time. They also found that clinical factors and reduced coping had no influence on sick leave when pain and function were taken into account. Both coping strategies and external factors (eg, lack of support from colleagues and supervisors) have been reported as barriers to or facilitators of working with arthritis (6–8). Thus, a claim for disability pension due to disease is not just dependent on the severity of the disease(s), but also the employer’s willingness to adjust the work and perhaps accept a lower level of productivity along with the willingness of colleagues to adapt accordingly. Several studies have indicated determinants for a person to have disability pension, eg, showing that low socioeconomic class, poor health, obesity, and smoking habits influence the risk. However, there are rather few studies on those who assess disability pension. The inter-rater agreement was reasonable (average 76%) when Dutch insurance physicians assessed the physical and mental functional capacity of written structured evaluations from trained nurses, while the inter-rater agreement was poor when physicians assessed the number of hours the claimant could function daily (9). A previous Dutch study –where four insurance physicians all examined and evaluated the same 30 patients with low-back pain – also showed poor inter-rater agreement (10). Another Dutch study of insurance physicians found modest inter-rater reliability in assessing patients with depressive disorders (11). A rather high inter-rater variability is common among medical specialists, eg, there is considerable variability among radiologists interpreting mammographies or describing lesions in sonography and pathologists describing dysplasia in the gastrointestinal system (12, 13). Among physicians (GP, internists and cardiologists) who rated the risk for coronary event and the need for lipid-lowering treatment in the same nine cases (14), there were considerable differences in rating risk and need for therapy even among physicians of the same specialty (eg, the concordance in risk estimates in high risk cases was only 0.31 among cardiologists). Furthermore, many more internists than GP wanted to start therapy in low-risk cases (45 versus 27%). High inter-rater variability may also occur in asthma diagnosis. In a study from Gothenburg, Sweden, 86 patients with asthma diagnosis from two primary healthcare units were re-evaluated by a specialist in allergic diseases. Asthma was verified in 57 patients (66%) (15). Fourteen pediatric asthma specialists were asked to classify eight patients classified as having asthma or asthma-symptoms (16).The agreement for diagnoses of asthma was very low: the kappa was 0.29. Their agreement was ever lower whether they based their classification symptoms or pulmonary functions tests (kappa=0.19). Dell-Kuster et al (1) indicated that financial interests may influence the assessments and the insurers paid the Swiss expert evaluators in their study. It is well-known that financial conflicts of interest may influence evaluations. Scientists with links to the pharmaceutical or tobacco industry make evaluations more favorable to the industry than neutral reviewers (17). It would be astonishing if physician evaluations were not influenced by those who pay them. From the point of the single claimant, the differences in evaluations may seem unacceptable. Medical doctors are typically trained to diagnose and treat patients. However, they have far less training in evaluating the capacities needed in working life. In the present working life, skills such as social capacity, learning new things, coping with stress etc are important for most workers in western societies. The solution is hardly to find the ultimate expert but rather to allow groups of “experts” with different types of expertise to give arguments for and against disability pension. The use of experts with no affiliations with either the insurer or the patient is a way to reduce bias caused by financial interests. Training experts and making them aware of the variability in evaluations would also be valuable. The use of video presentations for education and training of physicians have been suggested (18). Most patients have more than one diagnosis and several rather unique characteristics making algorithms less useful. Measuring the subjectivity involved in the evaluations and the variability between evaluators will contribute to improve the processes and make the assessors more humble to the sometimes difficult decision of deciding who shall have disability pension.