Influence of physical and psychosocial working conditions for the risk of disability pension among healthy female eldercare workers: Prospective cohort.

Aim: To investigate the influence of physical and psychosocial working conditions on the risk of disability pension among eldercare workers. Methods: After responding to a questionnaire in 2005, 4699 healthy female eldercare workers - free from chronic musculoskeletal pain, depressive symptoms and long-term sickness absence - were followed for 11 years in the Danish Register for Evaluation of Marginalization. Time-to-event analyses estimated the hazard ratio (HR) for disability pension from physical exertion during work, emotional demands, influence at work, role conflicts, and quality of leadership. Analyses were mutually adjusted for these work environmental factors as well as for age, education, smoking, leisure physical activity and body mass index. Results: During follow-up, 7.6% received disability pension. Physical exertion and emotional demands were associated with risk of disability pension, and both interacted with age. In age-stratified analyses, older eldercare workers (mean age 53 years at baseline) with moderate and high physical exertion (reference: low) were at increased risk with HRs of 1.51, 95% CI [1.06-2.15] and 2.54, 95% CI [1.34-4.83], respectively. Younger eldercare workers (mean age 36 years at baseline) with moderate emotional demands (reference: low) were at decreased risk with an HR of 0.57, 95% CI [0.37-0.85]. Conclusions: While a higher level of physical exertion is a risk factor for disability pension among older female eldercare workers, a moderate level of emotional demands is associated with lower risk among the younger workers. The age of the worker may be an important factor when providing recommendations for promoting a long and healthy working life.

Burnout as a predictor of self-reported sickness absence among human service workers: prospective findings from three year follow up of the PUMA study.

AIM: To investigate whether burnout predicts sickness absence days and sickness absence spells in human service workers. METHOD: A total of 824 participants from an ongoing prospective study in different human service sector organisations were eligible for the three year follow up analysis. Burnout was measured with the work related burnout scale of the Copenhagen Burnout Inventory. Sickness absence was measured with self-reported number of days and spells during the last 12 months before the baseline and the follow up survey. A Poisson regression model with a scale parameter was used to account for over dispersion. A linear regression model was used for analysing changes in burnout and absence between baseline and follow up. RESULTS: Burnout was prospectively associated with both sickness absence days and sickness absence spells per year. Differences in sickness absence days varied from a mean of 5.4 days per year in the lowest quartile of the work related burnout scale to a mean of 13.6 in the highest quartile. An increase of one standard deviation on the work related burnout scale predicted an increase of 21% in sickness absence days per year (rate ratio 1.21, 95% CI 1.11 to 1.32) after adjusting for gender, age, organisation, socioeconomic status, lifestyle factors, family status, having children under 7 years of age, and prevalence of diseases. Regarding sickness absence spells, an increase of one standard deviation on the work related burnout scale predicted an increase of 9% per year (rate ratio 1.09, 95% CI 1.02 to 1.17). Changes in burnout level from baseline to follow up were positively associated with changes in sickness absence days (estimate 1.94 days/year, SE 0.63) and sickness absence spell (estimate 0.34 spells/year, SE 0.08). CONCLUSION: The findings indicate that burnout predicts sickness absence. Reducing burnout is likely to reduce sickness absence.

Hodgkin's disease, pharyngeal cancer, and soft tissue sarcomas in Danish paper mill workers.

Several studies have indicated an increased cancer risk among paper mill workers, based on rather few cancer cases. The authors studied cancer incidence in a large historical cohort of 14,362 Danish paper mill workers, employed at any time between 1943 and 1990, and followed up until December 31, 1993. Men had an increased risk of pharyngeal cancer (15 observed (obs), standardized incidence ratio (SIR) 1.99, 95% confidence interval (CI) 1.11-3.29). With two additional cases among women, 11 of 17 cases were located in the tonsils. Men also had an increased risk of Hodgkin's disease (18 obs, SIR 2.01, 95% CI 1.19-3.18). Women had an increased risk of soft tissue sarcomas (nine obs, SIR 2.33, 95% CI 1.06-4.43), with a high risk among female paper sorters (eight obs, SIR 3.98, 95% CI 1.71-7.84). The study thus supports some studies' observations of an increased risk of Hodgkin's disease in paper mill workers. The detailed reporting of cancer cases in paper mill workers have furthermore revealed a risk of pharyngeal cancer together with a risk of soft tissue sarcomas in paper sorters.

Cancer incidence of sulfite pulp workers in Denmark.

OBJECTIVES: Studies have indicated an excess risk of stomach cancer, pancreas cancer, and non-Hodgkin's lymphoma for sulfite pulp mill workers, and therefore cancer incidence was evaluated for 2 Danish sulfite mills. METHODS: Altogether 2238 workers employed in 1955--1990 were included in a historic cohort and followed until 31 December 1993. National cancer rates were used to calculate the expected number of cancer cases. RESULTS: The overall cancer risk was close to the expected, the standardized incidence ratio (SIR) being 1.01. The risk of stomach cancer was doubled [10 observed, SIR 1.99, 95% confidence interval (95% CI) 0.95--3.66], as was the risk of pancreatic cancer (7 observed, SIR 1.88, 95% CI 0.75-3.88). For the men with known pulp exposure, lung cancer was slightly increased (SIR 1.53, 95% CI 0.94-2.37). Other cancers with elevated risks were leukemia (7 observed, SIR 1.84) and soft-tissue sarcomas (4 observed, SIR 2.37). The risk of non-Hodgkin' s lymphoma was not increased. CONCLUSIONS: The excess risk of stomach cancer and pancreatic cancer found in this study was in accordance with that of other studies from sulfite pulp mills.

Incidence of lung cancer among cobalt-exposed women.

OBJECTIVES: The purpose of this study was to estimate the risk of lung cancer for women occupationally exposed to cobalt-aluminate spinel. METHODS: A retrospective cohort of 874 women occupationally exposed to cobalt in two Danish porcelain factories and 520 women not exposed to cobalt were identified from personnel files. Vital status was assessed in the national population register, and incident cancer cases were traced in the national cancer register. Thirteen women (0.92%) were lost to follow-up. The observed deaths and incident cancer cases were compared with the expected number based on rates for all Danish women. RESULTS: The total mortality of the cohort was the same as for all Danish women. The incidence of all cancer was slightly elevated among the exposed women (67 observed, 55.8 expected) and equal to the expected in the reference group (60 observed, 60.6 expected). An increased lung cancer incidence was found both in the exposed group [8 cases, standardized incidence rate (SIR) 2.35, 95% confidence interval (95% CI) 1.01-4.6] and in the reference group (7 cases, SIR 1.99, 95% CI 0.8-4.1). The exposed group had a relative risk ratio of 1.2 (95% CI 0.4-3.8) when compared with the reference group. CONCLUSIONS: Both the cobalt-exposed group and the reference group had an increased lung cancer risk compared with all Danish women, but the risk was only slightly higher for the exposed group than for the reference group. The study was based on few persons, and we recommend a follow-up after five years.

[Lung cancer among asbestos-cement workers in Denmark]. / Lungekraeft hos asbestcementarbejdere i Danmark.

A cohort of 7887 men and 576 women employed between 1928 and 1984 at a Danish asbestos cement factory Dansk Eternit Fabrik A/S was followed up for deaths, immigrations, and incident cancer cases during 1943-90. The observed number of lung cancer cases was compared with the expected number based on incidence rates for the Danish population. Internal comparison was made with Poisson modelling. A total of 226 lung cancer cases was observed; 223 cases among men and three among women. The standardised incidence ratio (SIR) for all lung cancer cases for men was 1.7; for adenocarcinoma 2.6, squamous cell carcinoma 1.7, and anaplastic carcinoma 1.5. Among the 93 excess lung cancer cases, 36 were squamous cell carcinomas, 32 adenocarcinomas and 17 anaplastic carcinomas. During the first 25 years after the start of employment the excess risk was shared almost equally between the different histological types of lung cancer, but the risk of adenocarcinomas was clearly higher after this point.

Colorectal cancer in asbestos cement workers in Denmark.

Recent data on the risk of colorectal cancer following exposure to chrysotile are conflicting. We report on colorectal cancer morbidity in a large cohort of asbestos cement workers from Denmark mainly exposed to chrysotile. The total cohort had an SIR of 1.23 (95% CI 1.01-1.48). With a latency period of 15 years, men employed in the early (1928-1950) production period had an SIR of 1.47 (95% CI 1.05-2.01). With the observation of excess risks of colorectal cancer morbidity among chrysotile exposed asbestos cement workers in both Sweden and Denmark the question on the role of chrysotile in the etiology of colorectal cancer remains open.

Risk of cancer among paper recycling workers.

OBJECTIVES: Studies in traditional paper mills have indicated an excess cancer risk, and mutagenic compounds have been identified in the industry. No studies have reported on risk of cancer in paper recycling. Therefore the cancer incidence in Danish paper recycling mills was investigated. METHODS: 5377 employees in five paper recycling plants were included in a historical cohort study. The workers had been employed in paper recycling in 1965-90, and the cohort was followed up until 31 December 1993. The expected number of cancer cases was calculated from national rates. RESULTS: There was significantly more pharyngeal cancer among male workers (seven observed (standardised incidence ratio (SIR) 3.33, 95% confidence interval (95% CI) 1.34 to 6.87)). There was slightly more lung cancer among male workers in production (39 observed, SIR 1.21, 95% CI 0.86 to 1.65). Risk of Hodgkin's disease was doubled in male production worker (four observed, SIR 1.90, 95% CI 0.51 to 4.85). CONCLUSIONS: The increased risk of pharyngeal cancer found in this study is interesting but may be influenced by confounders such as smoking and alcohol intake. This study also indicates an excess risk of Hodgkin's disease, which is in accordance with some studies in the traditional paper mills. As this is the first report on risk of cancer in paper recycling, further studies are needed.

Lung cancer in asbestos cement workers in Denmark.

OBJECTIVES: To study the relative and absolute risks of main types of lung cancer in a cohort of asbestos cement workers from Denmark. METHOD: A cohort of 7887 men and 576 women employed between 1928 and 1984 was compiled from the personnel files of Danish Eternit Production. The cohort was followed up for deaths, emigrations, and incident cancer cases during the period 1943-90. The observed number of lung cancer cases in the cohort was compared with the expected number based on incidences for the Danish population. Internal comparison was made with Poisson modelling. RESULTS: A total of 226 lung cancer cases were observed (223 men and three women). The standardised incidence ratio (SIR) for all lung cancer among men was 1.7 (observed number 223, expected number 129.7, 95% confidence interval (95% CI) 1.5-2.0). The SIRs were raised for all main types of lung cancer; adenocarcinoma 2.6, squamous cell carcinoma 1.7, and anaplastic carcinoma 1.5. The higher SIR for adenocarcinomas was found particularly with a latency period of 25 years or more. Among the 93 excess lung cancer cases, 36 were squamous cell carcinomas and 32 were adenocarcinomas. CONCLUSION: Asbestos cement work is associated with an increased risk of lung cancer of all main types. During the first 25 years after the start of employment this excess risk is shared almost equally between the different histological types of lung cancer, but the risk of adenocarcinomas is clearly higher after this point.

Familial aggregation of colorectal cancer in the general population.

To investigate the familial aggregation of colorectal cancer in Denmark, parents and siblings of colorectal cancer patients diagnosed below age 60 years in the years 1982-1984 were identified through population registries. For 1,470 probands with families eligible for tracing, 1,376 mothers, 1,303 fathers and 3,259 siblings were identified. They contributed 222,634 person-years, and 325 cases of colorectal cancer were observed during the follow-up period 1943-1992. All data were retrieved from population registries and consequently were free from any reporting bias. The overall standardized morbidity ratio (SMR) compared with the Danish population was 2.02 (95% confidence interval [CI] 1.81-2.25), significantly different between the parents (1.78, 95% CI 1.55-2.04) and the siblings (2.65, 95% CI 2.21-3.17). A strong dependence on the proband's age at diagnosis was seen for the sibling risk; siblings of probands less than 50 years old at diagnosis had a 5-fold risk compared with the general population. This dependence was not seen for parents, but the risk tended to be higher for parents of younger ages. No other factor was seen to influence the relative risk. The observation of an 80% increased risk among the parents and a 170% increased risk among the siblings indicates that the genetic component is one source, but probably not the only one, of familial aggregation of colorectal cancer. The cost benefit of screening siblings of colorectal cancer patients is substantially higher than that for the total population.

Cancer in printing workers in Denmark.

OBJECTIVES: To study the cancer incidence in printing workers in Denmark. METHODS: The cohort of 15,534 men and 3593 women working in the printing industry in 1970 were followed up for death, emigrations, and incident cancer cases until the end of 1987. Their cancer incidence was compared with that of all economically active people in Denmark. The smoking and drinking habits reported by members of the printing trade unions at a survey in 1972 were compared with habits reported by members of other trade unions. RESULTS: Lung, bladder, renal pelvis, and primary liver cancers were in excess among the printing workers. The excess risks of lung cancer among the factory workers in newspaper and magazine production, of bladder cancer in typographers in printing establishments, of renal pelvis cancer in typographers and lithographers, and of primary liver cancer among lithographers and bookbinders exceeded those expected based on the reported smoking and drinking habits. CONCLUSION: Our results indicate, in line with a previous study from Manchester, that work with rotary letterpress printing was associated with an increased risk of lung cancer. The inconsistent results from studies on bladder cancer in printing workers may point to a risk confined to a certain subgroup. The sixfold risk of primary liver cancer in Danish lithographers warrants studies in other countries.

Breast cancer incidence after the start of mammography screening in Denmark.

Mammography screening may lead to overdiagnosis of asymptomatic breast cancers, that would otherwise not have given rise to clinical symptoms. This aspect was studied in three regional screening programmes in Denmark, which started in Copenhagen municipality, Fyn county, and Frederiksberg municipality in 1991, 1993, and 1994, respectively. In these regions, we compared time trends in incidence of invasive breast cancer with the rest of Denmark. Since the number of clinical mammograms was relatively low, it was reasonable to assume that the breast cancer incidence outside the three screening regions represented the incidence of a population with low-intensity opportunistic screening. In Copenhagen and Fyn, a prevalence peak in incidence was seen during the first invitation round. During the subsequent invitation rounds, the incidence dropped to a level in line with the incidence expected without screening. The pattern was different in the small municipality of Frederiksberg, where the sensitivity was low during the first invitation round. Inclusion of screen-detected ductal carcinoma in situ cases did not change these results. The experiences from Copenhagen and Fyn show that organised mammography screening can operate without overdiagnosis of breast cancer.