Risk factors for operated carpal tunnel syndrome: a multicenter population-based case-control study.

BACKGROUND: Carpal tunnel syndrome (CTS) is a socially and economically relevant disease caused by compression or entrapment of the median nerve within the carpal tunnel. This population-based case-control study aims to investigate occupational/non-occupational risk factors for surgically treated CTS. METHODS: Cases (n = 220) aged 18-65 years were randomly drawn from 13 administrative databases of citizens who were surgically treated with carpal tunnel release during 2001. Controls (n = 356) were randomly sampled from National Health Service registry records and were frequency matched by age-gender-specific CTS hospitalization rates. RESULTS: At multivariate analysis, risk factors were blue-collar/housewife status, BMI > or = 30 kg/m2, sibling history of CTS and coexistence of trigger finger. Being relatively tall (cut-offs based on tertiles: women > or =165 cm; men > or =175 cm) was associated with lower risk. Blue-collar work was a moderate/strong risk factor in both sexes. Raised risks were apparent for combinations of biomechanical risk factors that included frequent repetitivity and sustained force. CONCLUSION: This study strongly underlines the relevance of biomechanical exposures in both non-industrial and industrial work as risk factors for surgically treated CTS.

Disability insurance: can underwriting criteria for the self-employed be based on predictors used for disability amongst employees?

OBJECTIVE: This study aims to trace risk factors for disability amongst the self-employed. Knowledge about these risk factors can contribute to more evidence-based underwriting criteria for disability insurance. BACKGROUND: The trend towards privatization of social disability services in certain insurance markets creates a need to consider the appropriateness of underwriting criteria in applications for individual private disability insurance. METHODS: The authors performed a literature study and undertook a consultation amongst experts. RESULTS: More than 350 articles were traced. Only one article precisely matches the field of research: risk factors in underwriting disability insurance for the self-employed. Risk factors and medical characteristics in long-term disability are not identical between the employed and self-employed populations. Relevant risk factors for the self-employed are gender, age, occupational class, socioeconomic status, medical consumption, lifestyle, coping behavior, previous sick leave, replacement ratio and policy terms. CONCLUSIONS: The scarce amount of research on risk factors for disability amongst the self-employed forces insurers to rely on the limited statistical data available and pragmatic interpretation of this data. Underwriting criteria for the self-employed can partially be based on predictors for disability for employees. Whether the self-employed and employees are exposed to different risk factors or are basically different populations needs further research. The holistic approach of the International Classification of Functioning, Disability and Health model as a framework for developing a risk assessment model, with a strong focus on personal and environmental factors, will bring the current medical model at the underwriting stage more in line with the social model at claim stage.

Health Watch exposure estimates: do they underestimate benzene exposure?

A nested case-control study found that the excess of leukemia, identified among the male members of the Health Watch cohort, was associated with benzene exposure. Exposure had been retrospectively estimated for each individual occupational history using an algorithm in a relational database. Benzene exposure measurements, supplied by Australian petroleum companies, were used to estimate exposure for specific tasks. The tasks carried out within each job, the products handled, and the technology used, were identified from structured interviews with contemporary colleagues. More than half of the subjects started work after 1965 and had an average exposure period of 20 years. Exposure was low; nearly 85% of the cumulative exposure estimates were at or below 10 ppm-years. Matched analyses showed that leukemia risk increased with increasing cumulative benzene exposures and with increasing exposure intensity of the highest-exposed job. Non-Hodgkin lymphoma and multiple myeloma were not associated with benzene exposure. A reanalysis reported here, showed that for the 7 leukemia case-sets with greater than 16 ppm-years cumulative exposure, the odds ratio was 51.9 (5.6-477) when compared to the 2 lowest exposed categories combined to form a new reference category. The addition of occasional high exposures, e.g. as a result of spillages, increased exposure for 25% of subjects but for most, the increase was less than 5% of total exposure. The addition of these exposures reduced the odds ratios. Cumulative exposures did not range as high as those in comparable studies; however, the recent nature of the cohort and local handling practices can explain these differences.

Attitudes about electric and magnetic fields: do scientists and other risk experts perceive risk similarly?

Wherever there is electric power, 60-hertz (60-Hz) electric and magnetic fields (EMFs) are produced. Recently, conflicting reports have been published by government agencies about adverse health effects linked to EMFs. This paper seeks to identify the demographic and job-related factors that may explain differences among experts' perception of risk attributable to EMFs. Eighty-one participants at a bioelectromagnetics conference completed a survey on risk perceptions. Results indicated that education and employment sector were significant predictors of agreement with the statement that EMFs are not a problem. Future studies should look at the role of risk perception on environmental risk communication and determine the extent of message distortion, if any, based upon employment and demographic characteristics.

Updated mortality study of workers at a petroleum refinery in Torrance, California, 1959 to 1997.

The updated cohort consisted of 3328 workers who were employed at the Mobil (now ExxonMobil) Torrance, California, refinery for at least 1 year between 1959 and 1997. The vital status of the cohort was determined through a variety of sources, including company employment or retirement records, the Social Security Administration's Death Master File, and the National Death Index. The updated study covered an observation period of 38 years from 1960 to 1997, with a total of 60,612 person-years of observation. A total of 705 (21.2%) cohort members were identified as having died. Mortality data were analyzed in terms of cause-specific standardized mortality ratios (SMRs) and 95% confidence intervals (95% CIs), with expected deaths based on US national cause-, gender-, race-, year-, and age-specific mortality rates. The overall mortality of the cohort was significantly lower than expected when compared with the US general population (SMR, 81.9; 95% CI, 76.0 to 88.2). Overall cancer mortality was also lower than expected (SMR, 79.8; 95% CI, 67.9 to 93.1). For specific cancer sites, significant mortality deficits were observed for cancer of the digestive system (SMR, 70.9; 95% CI, 49.4 to 98.6) and cancer of the respiratory system (SMR, 74.1; 95% CI, 55.5 to 97.0). No significant increase was reported for any site-specific cancer. For nonmalignant diseases, no significant increase was observed for any cause. In particular, significant mortality deficits were reported for ischemic heart disease (SMR, 87.7; 95% CI, 77.2 to 99.3), chronic endocardial disease and other myocardial insufficiencies (SMR, 8.3; 95% CI, 0.2 to 46.0), all other heart disease (SMR, 64.2; 95% CI, 43.0 to 92.2), and influenza and pneumonia (SMR, 59.2; 95% CI, 33.1 to 97.6). Detailed analysis by length of employment did not reveal any significant mortality excess or upward trend. Analyses of male employees by job classification (process and maintenance) were conducted. Among maintenance workers, mortality from cirrhosis of the liver (SMR, 190.1; 95% CI, 101.2 to 325.1) and suicide (SMR, 208.6; 95% CI, 111.1 to 356.7) were significantly elevated. However, these mortality excesses did not seem to be related to employment at the refinery. No other causes of death showed significant increase among maintenance workers. A similar separate analysis was conducted for process workers, and no significant excess was detected for any cause. The findings from the present study are discussed in conjunction with results from previous investigations of employees at the Torrance refinery and with results from other refinery studies. Potential limitations of the study are also discussed.