Chronic lower respiratory diseases among demolition and cement workers: a population-based register study.

OBJECTIVE: To estimate standardised hospitalisation ratios (SHR) for chronic lower respiratory diseases among demolition and cement workers in Denmark, 1995-2009. DESIGN: This is a population-based register study on data from 'the Occupational Hospitalisation Register'. SHR of chronic obstructive pulmonary disease (COPD) was calculated for both demolition and cement workers. SETTINGS: Register study with data from all hospitals in Denmark. PARTICIPANTS: 895 demolition workers and 5633 cement and concrete workers were included in the study and all economical active men were used as reference group. RESULTS: We found a statistically significant high SHR for the cement workers, SHR=134 (95% CI 117 to 153). The SHR for demolition workers was 131 (95% CI 87 to 188). CONCLUSIONS: We find a higher risk of being hospitalised due to COPD in cement and concrete workers (significant) and demolition workers (insignificant) compared to gainfully employed men.

Time trend in hospitalised chronic lower respiratory diseases among Danish building and construction workers, 1981-2009: a cohort study.

OBJECTIVES: To show trends in age-standardised hospital admission ratios (SHR) for chronic lower respiratory diseases, estimated for Danish construction workers over three time periods (1981-1990, 1991-2000, 2001-2009). DESIGN: Within consecutive cohorts of all male building and construction workers in Denmark, selected occupations: bricklayers, carpenters, electricians, painters, plumbers and 'other construction workers' were followed up for hospitalisation due to chronic lower respiratory diseases. SHR was calculated for each occupation and time period. Time trend was calculated for construction workers at large using Poisson regression. SETTING: Denmark. PARTICIPANTS: All gainfully employed male building and construction workers aged 20 or more. PRIMARY AND SECONDARY OUTCOME MEASURES: Age-standardised and gender-standardised hospitalisation ratios (SHR). RESULTS: The number of hospitalised construction workers at large was reduced from 1134 in the first 10-year period to 699 in the last 9-year period. Among all Danish males, it was, however, even more reduced as reflected in the expected number that was down from 1172 to 617. Hence, SHR increased from 97 during 1981-1990, 100 during 1991-2000 to 113 during 2001-2009. It means that SHR increased with an average rate of 0.76% per year (95% CI 0.28 to 1.24) during the study period. A low SHR=72 (95% CI 60 to 87) was found among carpenters in 1981-1990. From 2001 to 2009, high SHRs were found among painters (SHR=147; 95% CI 111 to 192) and plumbers (SHR=132; 95% CI 101 to 171). In general, the selected groups of construction workers had, however, a low or average SHR due to chronic lower respiratory diseases. CONCLUSIONS: The number of hospitalised workers, suffering from chronic lower respiratory diseases, was reduced over time for construction workers, but for all economically active men, it was reduced even more. Therefore, SHR due to chronic lower respiratory diseases increased over time in the construction industry at large.

Occupation, morbidity, and hospital admission.

INTRODUCTION: The Occupational Hospitalization Register (OHR) is an ongoing register for research and surveillance established by the National Research Centre for the Working Environment in the 1980s. This review puts in perspective the contributions from the OHR to the understanding of relation between work and the burden of diseases in general and circulatory disease in particular. RESEARCH TOPICS: This review covers selected topics in which studies based on OHR has contributed to the scientific knowledge during more than two decades. One PhD thesis and so far 49 OHR studies have contributed to the estimation of the excess fraction of several diseases attributable to work and to the identification of relative risks for occupational diseases like circulatory diseases, diseases of the nervous system, musculoskeletal disorders, pulmonary disease, infertility, and recently also mental disorders. CONCLUSION: OHR is a cost-effective instrument for surveillance of health consequences of the working environment and social conditions as well as a valuable register for ad-hoc studies of the aetiology of occupational diseases.

Enterprise size and risk of hospital treated injuries among manual construction workers in Denmark: a study protocol.

BACKGROUND: In most countries throughout the world the construction industry continues to account for a disturbingly high proportion of fatal and nonfatal injuries. Research has shown that large enterprises seem to be most actively working for a safe working environment when compared to small and medium-sized enterprises. Also, statistics from Canada, Italy and South Korea suggest that the risk of injury among construction workers decreases with enterprise size, that is the smaller the enterprise the greater the risk of injury. This trend, however, is neither confirmed by the official statistics from Eurostat valid for EU-15 + Norway nor by a separate Danish study - although these findings might have missed a trend due to severe underreporting. In addition, none of the above mentioned studies controlled for the occupational distribution within the enterprises. A part of the declining injury rates observed in Canada, Italy and South Korea therefore might be explained by an increasing proportion of white-collar employees in large enterprises. OBJECTIVE: To investigate the relation between enterprise size and injury rates in the Danish construction industry. METHODS/DESIGN: All male construction workers in Denmark aged 20-59 years will be followed yearly through national registers from 1999 to 2006 for first hospital treated injury (ICD-10: S00-T98) and linked to data about employment status, occupation and enterprise size. Enterprise size-classes are based on the Danish business pattern where micro (less than 5 employees), small (5-9 employees) and medium-sized (10-19 employees) enterprises will be compared to large enterprises (at least 20 employees). The analyses will be controlled for age (five-year age groups), calendar year (as categorical variable) and occupation. A multi-level Poisson regression will be used where the enterprises will be treated as the subjects while observations within the enterprises will be treated as correlated repeated measurements. DISCUSSION: This follow-up study uses register data that include all people in the target population. Sampling bias and response bias are thereby eliminated. A disadvantage of the study is that only injuries requiring hospital treatment are covered.

The impact of self-reported exposure to whole-body-vibrations on the risk of disability pension among men: a 15 year prospective study.

BACKGROUND: Whole-body-vibrations are often associated with adverse health effect but the long term effects are less known. This study investigates the association between occupational exposures to whole-body vibrations, and subsequent transition to disability pension. METHODS: A total of 4215 male employees were followed up for subsequent disability pension retirement. Exposure to whole-body-vibration was self-reported while new cases of disability pension were retrieved from a national register. RESULTS: The hazard ratio (HR) for disability pension retirement among men exposed to whole-body-vibrations was 1.61 (95% confidence interval (CI) 1.07-2.40) after adjustment for age, smoking habits, BMI, physical job demands and awkward work postures. In our model, with the available explanatory variables, 5.6% of the male disability pension cases were attributable to whole-body-vibrations. CONCLUSIONS: Exposure to whole-body-vibrations predicts subsequent disability pension retirement. Continued reduction of whole-body-vibrations may reduce the number of new cases of disability pension.

Industry and injury related hospital contacts: a follow-up study of injuries among working men in Denmark.

OBJECTIVES: To estimate proportions of injuries that are attributable to the work environment (excess fractions) among economically active men and to identify industries associated with an elevated injury risk. METHODS: A follow-up study was conducted among all economically active men in Denmark aged 20-59 yr 1 January 1999 (N=1,315,772) for first hospital contacts in the period 1999-2003 due to injury in five body regions. Age standardised hospital treatment ratios (SHR) were calculated by industry and excess fractions were estimated. RESULTS: The excess fractions by body region attributable to the work environment were: 22% (95% CI 18-26%) for lower extremities, 29% (95% CI 24-34%) for head and neck, 31% (95% CI 25-37%) for thorax, 36% (95% CI 30-43%) for upper extremities, and 39% (CI: 32-46%) for back injuries. We identified eight industries associated with significantly elevated risks for injuries to each of the five body regions. These were: "road contractors", "bricklayer, joiner, and carpentry work", "finishing (construction work)", "transport of goods", "fire service and salvage corps", "stone-works, pottery, and glass industry", "cleaning, laundries, and dry cleaners", and "slaughterhouse industry". CONCLUSIONS: There are substantial industrial inequalities in injury rates among male workers in Denmark. The size of the inequalities differs between body regions.

Disability retirement among workers involved in large construction projects.

BACKGROUND: The aim of this study was to evaluate the incidence of disability pension among workers engaged in the construction of the Øresund Link or the Copenhagen Metro, representing high levels of safety management. METHODS: The study subjects (n = 1,808) were followed for disability retirement. Age standardized incidence ratios (SIRs) were calculated and compared with SIRs of disability pension established in a previous study of workers engaged in the construction of the Great Belt Link (N = 5,882), representing a low level of safety management. RESULTS: Compared with all economically active men, the age SIR of disability retirement was 2.22 (95% CI = 1.61, 2.98) among the study subjects and 2.29 (95% CI = 1.9, 2.67) among workers at the Great Belt Link. CONCLUSION: No significant progress was found in the incidence of disability pension among the study subjects despite substantial improvements in safety management compared with the Great Belt Link.

Hospitalization for lifestyle related diseases in long haul drivers compared with other truck drivers and the working population at large.

Personal lifestyle and working conditions are closely linked for long haul truck drivers. We compare lifestyle related diseases in long haul drivers with other drivers of goods and the working population at large. Standardized hospital treatment ratios (SHR) for lifestyle related diseases were compared for long haul truck drivers and other truck drivers to the working population at large. The follow up group comprised of 2,175 long haul drivers and 15,060 other truck drivers. An increased risk was found for lifestyle related diseases among truck drivers except for alcohol related diseases. We identified a strong association between hospital treatment for obesity and working as a driver and an association between diabetes and working as a driver. No major differences in lifestyle related diseases were found in long haul drivers compared to other truck drivers with the exception of a significant lower risk for alcohol-related diseases and a possibly higher risk for lung cancer in long haul drivers. It is concluded that diseases related to excess caloric intake or lack of exercise may be a problem for truck drivers. This risk is preventable and of importance both in occupational medicine as in public health.

Work-relatedness of mood disorders in Denmark.

OBJECTIVE: To determine the work-relatedness of mood disorders. METHODS: From 2001-2005, we followed up all economically active people in Denmark, aged 20-59 years as of January 2001, for hospital contact due to mood disorders. We calculated gender-stratified standardized incidence ratios (SIR) by industry. Using the distribution of the SIR values as input, we used a Monte Carlo simulation to estimate what proportion of the mood disorder cases could be regarded as work-related and denoted them as excess fractions. RESULTS: In total, we observed 10 731 cases of mood disorder among the women and 8305 among the men. There were four industries among women and 13 among men that showed elevated SIR with confidence intervals not including unity. The excess fractions without social group adjustment were 0.248 [95% confidence interval (95% CI) 0.173-0.325] for the women and 0.363 (95% CI 0.294-0.433) for the men. The respective fractions with adjustment for social group were 0.233 (95% CI 0.162-0.303) and 0.361 (95% CI 0.293-0.430). CONCLUSION: A substantial proportion of mood disorders among working people can be regarded as work-related. Hence, the workplace is an interesting arena for primary interventions.

Work injuries and disability.

PROBLEM: This study estimated the hazard ratio for disability pension retirement (DPR) for persons who have experienced a work injury causing absence lasting at least one day after the accidental injury occurred and to estimate the fraction of DPR attributable to work injuries. METHODS: A total of 4,217 male and 4,105 female employees from a national survey were followed up for subsequent DPR. RESULTS AND IMPACT ON INDUSTRY AND GOVERNMENT: Having had a work injury was a strong predictor of DPR among men. After control for age, smoking, body mass index, body postures, and physical demands, the hazard ratio (HR) among those employees who had ever experienced a work injury was 1.80 (95% confidence interval (CI): 1.20-2.68). No association was found among women. SUMMARY: Having had a reportable work injury is a strong predictor of subsequent DPR for men.

Differences between day and nonday workers in exposure to physical and psychosocial work factors in the Danish eldercare sector.

OBJECTIVE: The possible interaction between individual and occupational risk factors, the need for meaningful intervention, and the demand for valid shift work research make the accumulation of adverse exposures at certain times of the day of special relevance with respect to occupational health. The aim of the present study was therefore to examine whether there was a clustering of detrimental work factors among female eldercare workers in fixed evening or fixed night shifts when they are compared with workers in fixed day shifts. METHODS: This cross-sectional, questionnaire-based study was conducted among 4590 female health care workers in the Danish eldercare sector. The participants worked in nursing homes, in home care, or in both. They answered questions on job demands, job control, and social support, together with questions on physical and psychological violence, physical workload, and passive smoking. RESULTS: We found that-compared with day workers-fixed nonday workers were more exposed to low job control, low support from leaders, physical and psychological violence, and high physical demands. Nonday workers were, however, less exposed to high demands. These differences remained after control for age, job title, and workplace. CONCLUSIONS: Exposures in the work environment of Danish eldercare workers varied between shifts. In a research perspective these findings stress the importance of adequate adjustment for work factors when the health effects of shift work are studied. Moreover, the results underscore the need for an increased awareness of work factors of special importance among nonday workers when interventions against shiftwork-related occupational disorders are designed.

A nationwide population study of severe head injury and Parkinson's disease.

The aim was to analyze prospectively the association between severe head injury and Parkinson's disease. All people in Denmark who were at least 20 years old as on 1 January 1981 were followed for hospitalisation due to previous head trauma during 1981-1993 and for hospital contacts due to PD during 1995-2004. We observed 107 cases of PD among people at hypothetical risk due to previous head injury. The expected number was 112.1, which yielded a standardised morbidity ratio of 0.954 (95% CI: 0.782-1.15). The study provides no support for severe head injury among adults being a risk factor for Parkinson's disease.

Psychosocial working conditions and the risk of depression and anxiety disorders in the Danish workforce.

BACKGROUND: To examine the risk of depressive and anxiety disorders according to psychosocial working conditions in a large population-based sample. METHODS: Job Exposure Matrix was applied to assess psychosocial working conditions in a population-based nested case-control study of 14,166 psychiatric patients, diagnosed with depressive or anxiety disorders during 1995-1998 selected from The Danish Psychiatric Central Research Register, compared with 58,060 controls drawn from Statistics Denmark's Integrated Database for Labour Market Research. RESULTS: Low job control was associated with an increased risk of anxiety disorders in men (IRR 1.40, 95% CI 1.24-1.58). In women an elevated risk of depression was related to high emotional demands (IRR 1.39, 95%CI 1.22-1.58) and to working with people (IRR 1.15, 95% CI 1.01-1.30). In both sexes high demands were associated with a decreased risk of anxiety disorders. There was a weak association between job strain and anxiety disorders in men (IRR 1.13, 95%, CI 1.02-1.25) CONCLUSION: Psychosocial work exposures related to the risk of depressive and anxiety disorders differ as between the sexes. The pattern of risks is inconsistent. The results give rise to rethinking both study designs and possible causal links between work exposures and mental health.

Cardiovascular risk factors and primary selection into shift work.

OBJECTIVES: This study examined differences between future shift workers and future day workers as regards cardiovascular risk factors before they began different work schedules and the differences that remained after control for sociodemographic factors and general self-efficacy. METHODS: Altogether 2870 newly educated social and health care workers filled out a questionnaire a few weeks before finishing their formal training and again 1 year after graduation. They answered questions on diabetes, hypertension, lifestyle habits, sociodemographic factors, and general self-efficacy. RESULTS: In the unadjusted analyses, baseline obesity was associated with fixed evening work at follow-up. Minimal or light-to-moderate leisure-time physical activity was associated with a decrease in the odds ratio (OR) for two or three shifts including night work. Smoking status was associated with fixed evening work, fixed night work, and two- or three- shift work including night work. After adjustment for sociodemographic factors and general self-efficacy, smoking was prospectively associated with fixed evening work [OR 1.56, 95% confidence interval (95% CI) 1.21-2.02] and fixed night work (OR 1.64, 95% CI 1.04-2.56). Being an ex-smoker was associated with two- or three-shift work including night work (OR 1.85, 95% CI 1.28-2.68). The association between two- and three-shift work and smoking was only of borderline significance (OR 1.37, 95% CI 1.00-1.87). CONCLUSIONS: Compared with future day workers, fixed evening or fixed night workers already smoked more before they began shift work. Being an ex-smoker was significantly associated with two- or three-shift work including night work. These results indicate that smoking status should not solely be treated as a mediator between some variants of shiftwork schedules and cardiovascular diseases but should also be considered a confounder.

Hospital contacts for noise-related hearing loss among Danish seafarers and fishermen: a population-based cohort study.

AIMS: Noise-induced hearing loss (NIHL) is a leading occupational disease and some seafarers and fishermen may be at high risk. We present here standardized hospital contact ratios (SHCRs) for hearing loss among Danish seafarers and fishermen. MATERIALS AND METHODS: Cohorts of all Danish seafarers registered by the Danish Maritime Authority (DMA) and fishermen retrieved from a 1989-1998 pension registry were linked to the nationwide Occupational Hospitalisation Registry (OHR) with follow-up for NIHL from 1994 to 2003, using rates specific for age and calendar time for the entire Danish workforce as a reference. RESULTS: We found high SHCRs for NIHL: 165 [95% confidence interval (CI) 131-206] among officers, 113 (79-157) for nonofficers and 119 (85-162) for fishermen. The increased SHCR for hearing impairment among seafarers was solely found in engine room personnel (SHCR = 222; 95% CI 178-277). Compared to other seafarers, the engine room personnel had a relative risk ratio of 2.39 (95% CI: 1.74-3.26). Short-term employment is common in many trades. No duration response pattern was observed which may suggest a secondary healthy worker effect. CONCLUSIONS: These findings indicate that hearing problems are frequent among men who work in the engine rooms on ships. Long-term cumulative effects of employment were not shown.

Shift work and sickness absence.

BACKGROUND: Sickness absence is increasing in public work places in Denmark where shift work is common. AIMS: The aim of this prospective study was to predict the hazard ratio (HR) of short- and long-term sickness absence due to shift work in Danish shift workers. METHODS: A total of 1008 shift workers and 4009 day workers were followed up for short- and long-time sickness absence. RESULTS: Among shift workers, the HR of sickness absence lasting >or=2 weeks was 0.92 (95% CI: 0.71-1.18) for men and 0.90 for women (95% CI: 0.71-1.14). For sickness absence lasting >or=8 weeks, the HR was 1.33 (95% CI: 0.91-1.94) for men and 1.13 (95% CI: 0.81-1.59) for women. CONCLUSION: This study was inconclusive in proving any link between shift work and absenteeism after controlling for age, education, body mass index, smoking status, alcohol consumption, leisure time physical activity, psychosocial and physical work environment factors.

Hospital contacts for injuries and musculoskeletal diseases among seamen and fishermen: a population-based cohort study.

BACKGROUND: We studied musculoskeletal diseases (MSD) and injuries among fishermen and seamen with focus on low back disorders, carpal tunnel syndrome (CTS), rotator cuff syndrome and arthrosis. METHODS: Cohorts of all male Danish seamen (officers and non-officers) and fishermen employed 1994 and 1999 with at least six months employment history were linked to the Occupational Hospitalisation Register. We calculated standardised incidence ratios (SIR) for the two time periods, using rates for the entire Danish workforce as a reference. RESULTS: Among fishermen, we found high SIRs for knee arthrosis, thoraco-lumbar disc disorders, injuries and statistically significant SIRs above 200 were seen for both rotator cuff syndrome and CTS. The SIR was augmented for injuries and reduced for hip arthrosis between the two time periods. The SIRs for injuries and CTS were high for non-officers. A sub-analysis revealed that the highest risk for CTS was found among male non-officers working as deck crew, SIR 233 (95% CI: 166-317) based on 40 cases. Among officers, the SIRs for injuries and MSDs were low. The number of employed Danish fishermen declined with 25% 1994-1999 to 3470. Short-term employments were common. None of the SIRs increased with increasing length of employment. CONCLUSION: Both fishermen and non-officers have high SIRs for injuries and fishermen also for MSD. Only the SIR for injuries among fishermen was augmented between 1994 and 1999. Our findings suggest an association between the incidence of rotator cuff syndrome and CTS and work within fishery. Long-term cumulative effects of employment were not shown for any of the disease outcomes. Other conditions may play a role.

Does evening work predict sickness absence among female carers of the elderly?

OBJECTIVES: The aim of the present study was to predict the risk ratio of sickness absence lasting > or = 2 weeks due to shift work among Danish workers caring for the elderly during the evening and at night. METHODS: A sample of Danish carers of the elderly were interviewed in 2005. The response rate was 78%. A cohort of 5627 shift and day workers was followed for sickness absence lasting > or = 2 weeks and for sickness absence lasting > or = 8 weeks in a sickness compensation register covering all social transfer payments in Denmark. RESULTS: Among the evening workers, the rate ratio (RR) of sickness absence lasting > or = 2 weeks was 1.29 (95% confidence interval (95% CI) 1.10-1.52). The rate ratio for sickness absence lasting > or = 8 weeks was 1.24 (95% CI 0.99-1.56). CONCLUSIONS: Evening work may cause long-term sickness absence lasting > or = 2 weeks.

Locomotor diseases among male long-haul truck drivers and other professional drivers.

OBJECTIVE: High risks for locomotor diseases have been reported for bus and truck drivers in general; however, little is known about the specific risks of long-haul truck drivers. METHODS: Standardised hospitalisation ratios (SHR) for different locomotor diseases of bus drivers, long-haul truck drivers and other truck drivers were compared with each other and with the general Danish working population. RESULTS: Intervertebral disc disorders were more common among professional drivers (SHR: 119, 95% CI: 114-125) and of similar magnitude for cervical and non-cervical disorders. Both long-haul truck drivers and bus drivers had higher SHR for intervertebral disc disorders (SHR: 133, 95% CI: 114-155/SHR: 141, 95% CI: 129-154, respectively) than other truck drivers (SHR: 109, 95% CI: 102-116). The SHR for carpal tunnel syndrome was high among long-haul drivers (SHR: 163, 95% CI: 101-249) and for other truck drivers (SHR: 130, 95% CI: 108-156) compared to bus drivers (SHR: 110, 95% CI: 79-149). All drivers had high SHR for lesions of the ulnar nerve (SHR: 159, 95% CI: 119-207), especially bus drivers (SHR: 197, 95% CI: 116-311). Long-haul truck drivers had high SHRs for synovitis and bursitis (SHR: 150, 95% CI: 105-207), in contrast to other truck drivers and bus drivers (SHR: 103, 95% CI: 89-120/SHR: 87, 95% CI: 66-112, respectively). CONCLUSION: All groups of professional drivers experience high risk of various disorders of the locomotor system but type of vehicle and specific working conditions are associated with different health effects on the locomotor system.

Hospital contacts for chronic diseases among danish seafarers and fishermen: a population-based cohort study.

OBJECTIVES: Seafarers' and fishermen's working conditions may impact on their lifestyle and health. Standardized hospital contact ratios (SHCRs) were compared in two time periods and the relative risks of hospital contact as a function of employment time were estimated. METHODS: Cohorts of all Danish seafarers (officers and non-officers) registered by the Danish Maritime Authority (DMA) 1989-98 and fishermen retrieved from a pension registry 1989-98 were linked to the nationwide Occupational Hospitalization Registry (OHR) and followed up for incident diseases in two five-year time periods, from 1 January 1994 and 1 January 1999, respectively, using rates specific for age and calendar time for the entire Danish workforce as a reference. RESULTS: The SHCRs for lung and cardiovascular diseases were high for non-officers. Among male officers, the SHCR for diabetes was high in the 1999 cohort and the SHCR for chronic heart diseases was statistically significantly higher in the 1999 than in the 1994 cohort. For both time periods high SHCR values were found for bronchitis, emphysema, cancer of the lung, alcohol-related liver diseases, and diabetes among male non-officers, and lung cancer among male officers. Among female non-officers, a high SHCR for skin melanomas was seen. Among fishermen high SHCRs for bronchitis, emphysema, lung cancer, and Raynaud's syndrome were found in both cohorts. No duration-response pattern was observed in any of the analyses, which may reflect health- and lifestyle-related selection into the trades or a healthy worker effect. CONCLUSIONS: Danish seafarers, especially short-term employees, had an elevated risk of hospitalization for lifestyle-related diseases.