Epidemiology - 180 entries found
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Design of exposure questionnaires for epidemiological studies
Questionnaires are frequently used in epidemiological studies for occupational exposure assessment. This article discusses some of the issues that need to be taken into account when designing such questionnaires, namely: use of self-administered or interviewer-administered questionnaires; use of open ended or closed ended questions; use of proper wording; examples of poorly-worded questions; format of the questionnaire; useful complementary questions; pilot testing; translation; validity.
Occupational and Environmental Medicine, Apr. 2005, Vol.62, No.4, p.272-280. Illus. 30 ref.
Epidemiological surveillance of mortality and investigation of spatial and temporal clusters of cases. General principles and necessary data
Surveillance épidémiologique de la mortalité et investigation d'agrégats spatio-temporels en entreprise. Principes généraux et données nécessaires [in French]
The purpose of this methodological guide is to facilitate and to promote epidemiological surveillance of workers by conducting systematic epidemiological studies of medical causes of death and by investigating suspected clusters of cases. The major steps of mortality and incidence studies are presented, namely: constitution of a cohort; collection of mortality and incidence data; statistical methods used to calculate standardized mortality ratios (SMR) and standardized incidence ratios (SIR). Two mortality studies and one incidence study are provided as examples.
Institut de veille sanitaire, 12, rue du Val d'Osne, 94415 Saint-Maurice cedex, France, June 2004. 40p. Illus. 26 ref.
http://www.invs.sante.fr/publications/2004/surveillance_mortalite/surv_mortalite.pdf [in French]
Engrais minéraux [in French]
The ingestion of concentrated liquid fertilizers may severe cause severe acute poisoning due to the presence of high levels of potassium in these types of formulations. With the exception of a few cases of skin diseases and indications of mucous membrane irritation related to dusts, there are very few reports of harmful effects in occupational settings. Some fertilizer formulations containing calcium cyanamide may give rise to an antabuse effect. Excessive use of inorganic fertilizers results in the pollution of the water table by nitrates, which may then find their way into the water supply. Nitrates have been suspected of causing methaemoglobinaemia accidents in newborn children and cancers among the general population. However, their human toxicity has been largely overestimated. Methaemoglobinaemia in newborn children has been established to be caused by the bacterial pollution of water. It has not been possible to demonstrate any relationship between the long-term consumption of nitrate-rich water and cancers among the general population.
Encyclopédie médico-chirurgicale, Toxicologie-Pathologie professionnelle, 1st Quarter 2004, No.142, 5p. Illus. 41 ref.
The epidemic of asbestos-related diseases in New Zealand
New Zealand is a small country with a big asbestos disease problem. The lack of action on warnings in the 1960s and 1970s led to epidemics of mesothelioma and asbestosis, which can be clearly documented in the death and cancer registers. In addition, an uncertain number of lung cancers due to asbestos exposure have occurred. The epidemic started in the 1980s, and will eventually have cost the lives of at least 2,000 to 3,000 workers. Prevention against ongoing exposures from asbestos installed in buildings is essential. Finally, one should ensure that fair workers' compensation is provided to all victims of asbestos diseases in New Zealand.
International Journal of Occupational and Environmental Health, Apr.-June 2004, Vol.10, No.2, p.212-219. Illus. 18 ref.
http://www.ijoeh.com/pfds/1002_Kjellstrom.pdf [in English]
Seidler A., Nienhaus A., Diel R.
The transmission of tuberculosis in the light of new molecular biological approaches
This review briefly summarizes the recent achievements in tuberculosis epidemiology associated with the introduction of molecular methods, and considers the implications of these methods for the understanding of occupational tuberculosis transmission. Special attention is paid to the relative contribution of recently-transmitted tuberculosis, risk factors for recent transmission and the occurrence and frequency of exogenous re-infection. It is concluded that there is a need for occupational epidemiological studies that combine the methods of classical epidemiology with those of molecular epidemiology.
Occupational and Environmental Medicine, Feb. 2004, Vol.61, No.2, p.96-102. 71 ref.
Kennedy S.M., Koehoorn M.
Exposure assessment in epidemiology: Does gender matter?
This article explores whether the potential for gender-related differences should be taken into account in exposure assessment for epidemiologic studies. Evidence from previously-published studies and data from the investigators' own research were examined to investigate whether or not there were theoretical bases of gender bias in exposure assessment. Sources of bias examined included: practical differences in job tasks despite identical job titles; differences in exposure due to differences in protective equipment, body size or other factors related to exposure sources; differences in estimated exposure arising from study methods or design. Evidence was found for gender differences (and thus potential bias) from all these sources, but the magnitude and direction of the potential bias cannot be predicted.
American Journal of Industrial Medicine, Dec. 2003, Vol.44, No.6, p.576-583. Illus. 23 ref.
Zahm S.H., Blair A.
Occupational cancer among women: Where have we been and where are we going?
Estimates of the proportion of cancers among women attributable to occupation are based on research conducted mainly in the 1970s, among men and in developed countries. These studies do not reflect the important changes in the participation of women in the workplace during the last few decades or the patterns of employment of women in developing countries. Occupational cancer researchers need to expand their focus on women and on developing countries and new technologies. They should also use sophisticated exposure assessment methods, and, where appropriate, incorporate molecular epidemiological techniques to discover new occupational carcinogens and to identify the areas where better control measures are needed.
American Journal of Industrial Medicine, Dec. 2003, Vol.44, No.6, p.565-575. 129 ref.
Tinnerberg H., Heikkilä P., Huici-Montagud A., Bernal F., Forni A., Wanders S., Welinder H., Wilhardt P., Strömberg U., Norppa H., Knudsen L., Bonassi S., Hagmar L.
Retrospective exposure assessment and quality control in an international multi-centre case-control study
This article presents the exposure assessment method and quality control procedure used in an international, multi-centre case-control study within a joint Nordic and Italian cohort. The study was conducted to evaluate whether occupational exposure to carcinogens influenced the frequency of chromosomal aberrations in peripheral lymphocytes, giving rise to an increased cancer risk. Occupational hygienists assessed exposures in each participating country: Denmark, Finland, Italy, Norway and Sweden. An independent Spanish occupational hygienist team coordinated harmonization of the assessment criteria and the quality control procedure. Variations in exposures assessed by the different assessors are discussed, together with the implications for the consistency of exposure assessments in international retrospective case-control studies.
Annals of Occupational Hygiene, Jan. 2003, Vol.47, No.1, p.37-47. Illus. 24 ref.
Messing K., Punnett L., Bond M., Alexanderson K., Pyle J., Zahm S., Wegman D., Stock S.R., de Grosbois S.
Be the fairest of them all: Challenges and recommendations for the treatment of gender in occupational health research
Both women's and men's occupational health problems merit scientific attention. Researchers need to consider the effect of gender on how occupational health issues are experienced, expressed, defined and addressed. More serious consideration of gender-related factors will help identify risk factors for both women and men. This article discusses some of the ways in which gender can be and has been handled in studies of occupational health, as well as some of the consequences. It also suggests specific research practices that avoid errors. Obstacles to gender-sensitive research practices are considered. Although gender-sensitive practices may be difficult to implement in some cases, they enrich the scientific quality of research and should lead to better data and ultimately to better-targeted prevention programmes.
American Journal of Industrial Medicine, June 2003, Vol.43, No.6, p.618-629. 157 ref.
Miller B.G., Graham M.K., Creely K.S., Cowie H.A., Soutar C.A.
Health and Safety Executive
Questionnaire predictors of asthma and occupational asthma
This study provides information towards the development of a questionnaire to identify work-related asthma. A previous postal survey of a community in central Scotland provided a complete data set for almost 12,000 subjects of working age, with responses to a range of questions on respiratory symptoms and their relationship to occupation. For those subjects who had recorded the occupation held when symptoms began, the existing data were augmented by an exposure assessment to characterize exposures typical of those occupations. Certain symptoms were associated, tending to occur together, and a number of syndromes were defined in terms of these. Some limited associations between these syndromes and occupational exposures were identified, particularly with irritant and highly reactive chemicals, and exposure to proteins and other organic substances. These data will be useful for the development of a new questionnaire.
HSE Books, P.O. Box 1999, Sudbury, Suffolk CO10 2WA, United Kingdom, Sep. 2003. viii, 80p. Illus. 29 ref. Price: GBP 15.00.
http://www.hse.gov.uk/research/rrpdf/rr164.pdf [in English]
Advisory Committee on Existing Chemicals of Environmental Relevance (BUA)
Tributyltin oxide (No.36)
Conclusions of this criteria document on tributyltin oxide (TBTO): animal experiments show TBTO to be acutely toxic by ingestion and harmful by skin absorption. Inhaled TBTO aerosols are highly toxic. TBTO exposure is followed by rapid distribution, the main target organs being the liver, kidneys and the haematopoietic system. TBTO is immunotoxic. It is severely irritating to the skin and mucous membranes, and causes contact allergy. TBTO is not mutagenic, and is clastogenic only at cytotoxic concentrations. It does not affect fertility. In man, studies indicate that TBTO vapours cause nausea, vomiting, headaches, sore throat, irritation of the mucous membranes, and it can trigger asthma. Dermal contact with liquids containing TBTO can cause irritant skin lesions.
S. Hirzel Wissenschaftliche Verlagsgesellachaft, P.O. Box 10 10 61, 70009 Stuttgart, Germany, 2003. xx, 108p. 220 ref. Price: EUR 49.50.
Occupational skin-disease data in Europe
The existence of different occupational health systems and legislations in the countries of Europe makes it difficult to obtain a detailed picture of occupational skin diseases for the whole continent. Reporting bias and selection bias have a considerable impact on the perceived prevalence and incidence, while reliable data are hard to extract from official registries. In this article, data from one region in Germany are taken as an example. Comparison with data from other sources yields an estimate of 0.7 to 1.5 cases per 1,000 per year as a gross average, while the problem in specific occupational groups is more pronounced. However, reliable data on social and economic impact are very scarce.
International Archives of Occupational and Environmental Health, June 2003, Vol.76, No.5, p.331-338. Illus. 51 ref.
The importance of occupational skin diseases in the United States
Occupational skin diseases and disorders (OSDs) are the most commonly reported non-trauma-related (acute or cumulative) category of occupational illnesses in the United States. This factor, along with their potential chronicity, their effect on an individual's occupational and non-occupational activities, and the fact that they are preventable, point out the public health importance of OSDs. It can be difficult to obtain accurate epidemiological data for OSDs in the United States, and all sources have their limitations. OSD cases that result in days away from work are important categories to study, since days away from work may be used as an indicator of the severity of a case. Descriptive epidemiology may be used to provide further information on these "more severe" cases, to determine, for example, high-risk industries, occupations, and exposures, and then to use this information to focus prevention strategies.
International Archives of Occupational and Environmental Health, June 2003, Vol.76, No.5, p.325-330. Illus. 22 ref.
Massin N., Choudat D.
Cross-sectional epidemiological studies
Etudes épidémiologiques transversales [in French]
In cross-sectional epidemiological surveys, subjects that are included in the sample are subjected to investigations that are limited in time, allowing research to focus on issues that are present at the time of the study. These cross-sectional studies can be either descriptive or analytical. Descriptive cross-sectional studies focus on the frequency and distribution of diseases and health indicators. They enable the creation, the description and in some cases the comparison of data on the state of health of populations. The objective of analytical cross-sectional surveys is to highlight the relationship between health effects and exposures. Cross-sectional studies may be carried out at repeated intervals, thereby giving a longitudinal view of the data. In these cases also, the approach can be either descriptive, for example in epidemiological surveillance studies, or less frequently, analytical.
Encyclopédie médico-chirurgicale, Toxicologie Pathologie professionnelle, 1st Quarter 2003, No.138, 6p. Illus. 22 ref.
Radon K., Goldberg M., Becklake M.
Healthy worker effect in cohort studies on chronic bronchitis
Two mechanisms are responsible for the healthy worker effect in respiratory cohort studies. One is health-based selection of workers into employment (healthy hire effect), and the other is health-based losses over time (healthy worker survivor effect). The aim of the present paper was to estimate the magnitude of the healthy worker survivor effect in cohort studies of chronic bronchitis. A meta-analysis of eight cohort studies published between 1980 and 2001 was performed. The pooled odds ratio of the prevalence of chronic bronchitis for subjects leaving the cohorts was 1.23 when these subjects were compared with those who remained under study. The prevalence of respiratory symptoms among exposed workers may be underestimated if the healthy worker survivor effect is not taken into account.
Scandinavian Journal of Work, Environment and Health, Oct. 2002, Vol.28, No.5, p.328-332. Illus.27 ref.
Alternative for estimating the burden of lung cancer from occupational exposures - Some calculations based on data from Swedish men
This study attempts to calculate the occupational lung cancer burden using economically active men in Sweden as an example. Risk estimates were calculated using Swedish register data on occupation in 1970, lung cancer incidence in 1971-1989, smoking frequencies in 1963 and a mathematical formula. Farmers, gardeners, forestry workers and fishermen had the lowest lung cancer risk (42.1 per 100,000 person-years) and a smoking frequency of 44.7%. The incidence among those not at risk (non smokers, Io) was 12.6 or 8.4 per 100 000 person-years, taking a relative risk for smoking as 6 or 10, respectively. From these Io estimates, the expected rates for white- and blue-collar workers (smoking frequencies 52.7 and 57.7%, respectively) were 45.8 and 49.1 per 100 000 person-years. About one-fourth of the lung cancers that occur among economically active Swedish men seem to have been related to occupation. This figure agrees with other estimates.
Scandinavian Journal of Work, Environment and Health, Feb. 2002, Vol.28, No.1, p.58-63. 24 ref.
Karjalainen A., Kurppa K., Martikainen R., Karjalainen J., Klaukka T.
Exploration of asthma risk by occupation - Extended analysis of an incidence study of the Finnish population
In Finland, persons with clinically-verified persistent asthma are registered for medication reimbursement by the national health insurance scheme. Data were combined from three national registers, and all employed Finns aged 25-59 were followed for asthma incidence in 1986-1998. A log-linear model was used to estimate the relative risks of asthma for 275 nonadministrative occupations in comparison with administrative work (33 occupations). A significantly increased risk was found for either men or women in 125 occupations. For the men, the risk was highest among bakers, laundry workers, shoemakers and repairers, tanners, fell mongers and pelt dressers, and metal plating and coating workers. For the women, the risk was highest among shoemakers and repairers, railway and station personnel, jewelry engravers, engine room crew, molders, round-timber workers and bakers. The results suggest that the work-related excess of asthma incidence is much more widely spread across the labour force than previously thought.
Scandinavian Journal of Work, Environment and Health, Feb. 2002, Vol.28, No.1, p.49-57. 18 ref.
McCanlies E., Landsittel D.P., Yucesoy B., Vallyathan V., Luster M.L., Sharp D.S.
Significance of genetic information in risk assessment and individual classification using silicosis as a case model
This study addresses how, given a known exposure, genetic information affects the characterization of risk groups. The probability of developing silicosis in a population of coal miners in Turkey was estimated using logistic regression on the basis of lung tissue samples from autopsy. This probability was then used to construct predicted risk deciles, first for a model with occupational exposure only, and later for a model containing occupational exposure and genetic main effects and interactions. The results indicate that genetic information plays a valuable role in effectively characterizing risk groups and mechanisms of diseases in a substantial proportion of the population. However, in the case of fibrotic lung disease caused by silica exposure, information about the presence or absence of the minor variants of interleukin-1α, interleukin-1 receptor antagonist and tumour necrosis factor-α is unlikely to be a useful tool for individual classification.
Annals of Occupational Hygiene, June 2002, vol.46, No.4, p.375-381. Illus. 21 ref.
Silicosis in sandblasters - A case study adapted for use in U.S. high schools
More than two million workers in the United States are potentially exposed to dusts containing crystalline silica. Prolonged inhalation of silica-containing dusts puts these workers at risk of silicosis, a fibrosis of the lungs that causes shortness of breath. More than 100,000 workers in the United States are in high-risk occupations such as sandblasting. The purpose of this booklet is to explain the basic principles of epidemiology to high school students, using the example of silicosis among sandblasters. Contents: glossary; case study of silicosis among oil field drilling pipe sandblasters; understanding silicosis; prevention of silicosis; suggested reading.
Publications Dissemination, National Institute for Occupational Safety and Health (NIOSH), 4676 Columbia Parkway, Cincinnati, OH 45226-1998, USA, June 2002. 21p. Illus. 10 ref.
http://www.cdc.gov/niosh/docs/2002-105/2002-105.html [in English]
Leigh J., Mayhew C.
Occupational risk factors in the WHO global burden of disease: Comparative risk assessment study
The World Health Organization (WHO) has been conducting a series of international studies connected with the Global Burden of Disease project. These studies have been aimed at developing best estimates of the disease burden borne by the total human population. It is recognized that occupational factors are core contributors to the burden of short and long-term disability and death. This article briefly reviews the original Global Burden of Disease project, provides background information on the more recent stage of the project involving comparative risk assessment and presents detailed information on the contributions made to the project by Australian occupational safety and health researchers.
Journal of Occupational Health and Safety - Australia and New Zealand, Aug. 2002, Vol.18, No.4, p.339-346. 44 ref.
Park R.M., Bailer A.J., Stayner L.T., Halperin W., Gilbert S.J.
An alternate characterization of hazard in occupational epidemiology: Years of life lost per years worked
This article describes an alternative approach to standardized mortality ratios (SMRs) for describing occupational hazards based on years of potential life lost and lifetime risk, providing a more intuitive view of occupational mortality risk. The approach was evaluated for fatal lung diseases and injuries in a cohort of uranium miners with historical records of exposure to radon. Among miners hired after 1950 whose all-cause SMR was 1.5, 28% experienced premature death from lung diseases or injury. On average, each miner lost 1.5 years of potential life due to lung cancer, or almost three months for each year employed in uranium mining. As a consequence of lung disease and injury risks combined, a year of mining was associated with 5.9 months loss of potential life. For each year actually working underground, miners lost more than eight months of potential life. Fatal-injury dominated the potential years of life lost up to about age 40.
American Journal of Industrial Medicine, July 2002, Vol.42, No.1, p.1-10. Illus. 28 ref.
Proceedings of the Symposium on 30 years of epidemiology for the benefit of occupational health
Proceedings of a conference held on 8 February 2002 in Helsinki, Finland, to commemorate the 30 years since the creation of the department of epidemiology and biostatistics at the Finnish Institute of Occupational Health. Topics presented: historical overviews of occupational health research in Finland, theoretical developments in epidemiology, surveillance of working conditions and health; cooperation in epidemiological research; current and future research priorities.
Finnish Institute of Occupational Health, Publication Office, Topeliuksenkatu 41 a A, 00250 Helsinki, Finland, 2002. 85p. Illus. Bibl.ref.
Nurminen M., Karjalainen A.
Epidemiologic estimate of the proportion of fatalities related to occupational factors in Finland
This study attempts to estimate the proportion of annual deaths related to occupational factors in Finland. Statistics on causes of death, numbers of subjects exposed, and risk ratios obtained from the epidemiological literature were used. Sex-, age- and disease-specific numbers of deaths were provided by Statistics Finland for 1996. The fraction of work-related mortality was estimated to be 7% (10% for men and 2% for women). For the main cause-of-death categories, the attributable fractions were 12% for circulatory system diseases, 8% for malignant neoplasms, 4% for respiratory system diseases, 4% for mental disorders, 3% for nervous system diseases, and 3% for accidents and violence.
Scandinavian Journal of Work, Environment and Health, June 2001, Vol.27, No.3, p.161-213. Illus. 340 ref.
Evaluating composite health measures using Rasch modelling: An illustrative example
Rasch modelling is a statistical framework that addresses the issues of uni-dimensionality and invariance. The purpose of this article is to explore the possibilities of applying Rasch modelling to epidemiology and public health research in order to evaluate composite measures of health. It provides an overview of Rasch modelling using examples based on adolescent survey data. It shows how the various elements operate across different samples and subgroups. It concludes that Rasch modelling may serve as a useful tool in the evaluation and the development of composite health measures intended to be used in epidemiology and public health research.
SPM - Sozial- und Präventivmedizin - Social and Preventive Medicine - Médecine sociale et préventive, 2001, Vol.46, No.6, p.369-378. Illus. 34 ref.
Choi B.C.K., Pak A.W.P.
Lessons for surveillance in the 21st century: A historical perspective from the past five millennia
This paper reviews some major epidemics in the past 5000 years in human history and derives 12 lessons in the context of epidemiological surveillance, to be used as a guide to designing a better and more comprehensive surveillance systems in the future. The elements of such an improved system include: continuing the improvement of surveillance; carrying out surveillance on an ongoing basis; being systematic; being population-based; including risk and prevention indicators in the database; linking surveillance with an efficient data analysis system; simulating aetiological research; improving forecasting capability; linking of development of intervention; evaluating the intervention; improving information dissemination; ensuring that the surveillance system provide equal opportunity for participation and receipt of information.
SPM - Sozial- und Präventivmedizin - Social and Preventive Medicine - Médecine sociale et préventive, 2001, Vol.46, No.6, p.361-368. 31 ref.
Zahm S.H., Blair A.
Feasibility of epidemiologic research on migrant and seasonal farmworkers
This special issue contains 15 reports of pilot projects from the Farmworker Epidemiology Research Group, designed to assess the feasibility of conducting epidemiological studies on migrant and seasonal farmworkers. Funded by the National Cancer Institute and the Migrant Health Program, this work began after a review in 1993 found that despite concerns about exposure to potentially carcinogenic pesticides, there were few studies on cancer among farmworkers. It was believed that reasons for this lack of data included the difficulties of conducting epidemiological studies on a highly-mobile population, often with little education or understanding of English and with lengthy, complex job histories. The projects reported address issues of questionnaire design, assessment of pesticide exposures, tracing, evaluating cancer incidence and mortality, and establishing a cohort of farmworkers for future follow-up.
American Journal of Industrial Medicine, Nov. 2001, Vol.40, No.5, p.487-618 (whole issue). Illus. Bibl.ref.
How much protection against radon do we need?
It has been long established that exposure to radon contributed to lung cancer risk among miners in the past. However, based on recent epidemiological data that the author considers controversial, regulators currently favour linear extrapolation from the very high exposures encountered in mining to low residential radon exposures. Direct and indirect evidence are reviewed and it is argued that this approach may be misleading due to various perturbing factors, in particular the retrospective determination of smoking habits.
Central European Journal of Occupational and Environmental Medicine, 2001, Vol.7, No.3-4, p.168-177. Illus. 19 ref.
Sorock G.S., Lombardi D.A., Courtney T.K., Cotnam J.P., Mittleman M.A.
Epidemiology of occupational acute traumatic hand injuries: A literature review
In 1996, the leading occupational injury treated in United States' hospital emergency departments was an acute hand injury (e.g. laceration, crush or fracture), affecting 990,000 workers, and representing 30% of all occupational injuries. Cuts and lacerations of the fingers ranked third after back and leg strains in the number of lost workday cases in the USA in 1994. The incidence rate of hand injuries studied in seven manufacturing environments around the world ranged from 4 to 11 per 100 workers per year. Workers aged 24 years or less had the highest risk of hand injury. Men had higher rates of severe hand injury than women. There is only one case-control study of occupational hand injury in the literature, which suggested an important role for both fixed (age) and transient risk factors (doing an unusual task) at the time of the injury. Suggestions are made for further research.
Safety Science, Aug. 2001, Vol.38, No.3, p.241-256. 56 ref.
Method of data collection on the health effects of occupational hazards
Mode de recueil des effets sur la santé en épidémiologie des risques professionnels [in French]
The method of collecting information on the health effects of occupational hazards depends on the nature of the health effect observed, its latency and the methodology of the study undertaken. Various modes of collection are described, including active collection by means of questionnaires, assessment scales, recording of clinical symptoms or diseases through medical examination and standardized clinical tests, the use of early clinical, functional or biological markers, and the recording of morbidity and mortality from usable sources of data. Examples of information collection methods for the study of selected diseases are provided, including neurobehavioural disorders, mental health, respiratory diseases and cumulative trauma disorders of the upper extremities. The mode of collection of health effect information has an influence on the quality of the study with respect to its results, conclusions and suggested future preventive actions.
Encyclopédie médico-chirurgicale, Toxicologie-Pathologie professionnelle, 3rd Quarter 2001, No.132, 7p. 57 ref.
Leclerc A., Lellouch J.
Glossary of statistical and epidemiological terms
Glossaire statistique et épidémiologique [in French]
Glossary of approximately 130 statistical terms used in epidemiological studies, with comprehensive definitions. A lexicon giving the French equivalent of frequently-used English terms is also included.
Encyclopédie médico-chirurgicale, Toxicologie-Pathologie professionnelle, 2nd Quarter 2000, No.127, 15p. 10 ref.
Grzebyk M., Chouanière D., Wild P.
Statistical models applied to neurobehavioural epidemiology
Modèles statistiques appliqués à l'épidémiologie neuro-comportementale [in French]
Neurobehavioural epidemiological studies use psychometric testing for generating specific multi-variate data. This report summarizes the results of a study aimed at developing a statistical analysis method suited for multi-variate analysis. Upon reviewing published literature describing appropriate statistical methods, the linear latent variable model was selected. It was first tested and validated on simulated variables, then applied to two sets of real data, one from a cross-sectional study on the neurotoxicity of toluene, and the other on a study aimed at estimating the incidence of insanity among aged persons and identifying the risk factors. Through these different applications of the model, it was possible to develop a better understanding of its applicability and its limitations.
Institut national de recherche et de sécurité, 30 rue Olivier-Noyer, 75680 Paris Cedex 14, France, June 2000. 99p. Illus. 48 ref.
Soutar C.A., Robertson A., Miller B.G., Searl A., Bignon J.
Epidemiological evidence on the carcinogenicity of silica: Factors in scientific judgement
In view of the extended debate and differing opinions on whether crystalline silica is a human carcinogen, a selection of epidemiological reports was reviewed in order to identify the areas of uncertainty and disagreement. Papers which in a recent review were considered to provide the least confounded examinations of an association between silica exposure and cancer risk have been examined together with a study of the mortality of coalminers. It has been found that parts of the evidence were coherent but there were contradictions. On examination, this resolved mostly into differences between types of studies. The three types of epidemiological study included were: exposure-response studies, studies in which incidence of disease in an exposed population is compared with that in a reference population and studies of incidence of disease in subjects on silicosis case-registers. Scientific uncertainties in the evidence (confounders, bias, false assumptions) are discussed.
Annals of Occupational Hygiene, Jan. 2000, Vol.44, No.1, p.3-14. 69 ref.
Jędrychowski W., Vena J., Maugeri U.
Challenges to epidemiology in changing Europe - Proceedings of the conference - Krakow, July 2-3, 1999
Proceedings of a conference on epidemiology in Europe held in Cracow, Poland, 2-3 July 1999. Main topics covered: health and environment trends in the 1990s; increase of asthma worldwide; epidemiology of cancer in Europe; infectious diseases in Poland; mesothelioma in Europe; incidence of malignancies caused by arsenic in populations exposed to high arsenic-containing coal combustion products; incidence of type-1 diabetes in age groups 0-10 and 15-29 in Cracow; future chronic diseases; multidisciplinary research; current and future trends in epidemiology; challenges for epidemiologists in Europe; linkage between epidemiology and health policy; evidence-based primary prevention.
Polish Society for Environmental Epidemiology, Dept. of Epidemiology and Preventive Medicine, Medical School, Jagiellonian University, 7 Kopernika street, 31034 Krakow, Poland, 1999. 248p. Illus. Bibl.ref.
Mode of collecting data on health effects during epidemiological studies on occupational safety and health
Mode de recueil des effets sur la santé en épidémiologie des risques professionnels [in French]
The preferred mode of collecting epidemiological data on the health effects of occupational hazards depends on the type of the health effect being followed and its latency, as well as the research methodology. Various modes of data collection are described: active collection by means of questionnaires, evaluation scales, recording of pathologies or clinical symptoms during medical examination and standardized clinical tests, collection of morbidity and mortality data from useable sources. Examples of modes of data collection are given for selected diseases: neurobehavioural disorders, mental health, respiratory diseases, repetitive strain injury. Use of a suited mode of data collection strongly determines the reliability of the data, and can influence the conclusions of the study and the corresponding occupational safety and health action plans.
Encyclopédie médico-chirurgicale, Toxicologie-Pathologie professionnelle, 4th Quarter 1999, No.125, 7p. 57 ref.
Loomis D., Salvan A., Kromhout H., Kriebel D.
Selecting indices of occupational exposure for epidemiologic studies
Decisions about how best to describe the magnitude or timing of exposure are challenging in almost every epidemiological study because the number of possible representations of any epidemiological relationship is large, but knowledge is limited. This paper seeks to promote a discussion of problems surrounding the selection of indices of exposure for epidemiological studies in occupational health. Five themes are considered: general approaches to selecting exposure indicators; measurement error; exposure-time or latency analysis, dosimetric models, and philosophical issues in exposure-response modeling. It is proposed to focus future research on the properties of measurement error, dosimetric models, and other advanced exposure estimation techniques. A need also exists for more deliberate development of epidemiological theory and an ongoing examination of research methods in relation to goals for science and public health.
Occupational Hygiene, 1999, Vol.5, No.1, p.73-91. 47 ref.
Methodology for analyzing episodic events
Epidemiological approaches to the study of episodic health events are reviewed. Episodic events are defined as events that occur suddenly or that suddenly cross a threshold, but with onsets at distinct points in time. Studying such health events poses four challenges to existing methods: key epidemiological concepts, such as incidence, do not naturally accommodate recurrent events; study designs must capture time-varying exposures; statistical models must be able to handle correlated outcomes; and feedback bias must be addressed. In response, methods such as longitudinal studies, case-crossover designs and generalized estimating equations are identified as appropriate tools.
Scandinavian Journal of Work, Environment and Health, 1999, Vol.25, Suppl.4, p.36-42. Illus. 20 ref.
Challenges for research and prevention in relation to work and cardiovascular diseases
The purpose of this paper is to discuss future challenges for research and prevention in the field of work environment and cardiovascular diseases (CVD). Firstly, research on CVD and work during the last half of the 20th century is discussed. Secondly, the theories dominating the last 20 years are presented. Thirdly, cardiovascular and occupational epidemiology are compared, and it is stressed that occupational epidemiology should avoid the individualistic bias of mainstream cardiovascular epidemiology. Finally, future challenges are discussed, and improvements are recommended concerning the use of intermediate end points, intervention research, chemical and physical risk factor theories, the use of a unifying model for society, stress and health, and the application of integrated prevention. It is concluded that research on CVD and work can play an important part in the development of integrated prevention strategies for the next century.
Scandinavian Journal of Work, Environment and Health, Dec. 1999, Vol.25, No.6, p.550-557. Illus. 69 ref.
Promise of molecular epidemiology - Epidemiological reasoning, biological rationale and risk assessment
Molecular epidemiology has emerged as a natural outgrowth of attempts to apply information derived from the rapid increase in the application of molecular biology to diseases. The incorporation of biomarkers into classical epidemiologic designs holds the promise of unrevealing mechanisms, elucidating gene-environment interactions, and dissecting heterogeneity. The primary interest of molecular epidemiology is in the identification of factors in the physical and social environment which affect the risk for disease and which are amenable to preventive intervention. As experience accumulates, there is new appreciation that attention to study design, infrastructure and biomarker validation can improve the results.
Scandinavian Journal of Work, Environment and Health, Dec. 1999, Vol.25, No.6, p.498-504. 30 ref.
Diepgen T.L., Coenraads P.J.
The epidemiology of occupational contact dermatitis
Occupational contact dermatitis ranks first of all occupational diseases in many countries. The incidence rate is believed to be around 0.5-1.9 cases per 1,000 full-time workers per year. Epidemiological studies play an important role in observing disease trends, analysing risk factors, and monitoring the effect of preventive measures. This review article highlights the lack of reliable epidemiologic data on occupational contact dermatitis and the difficulties of such studies. The following issues are highlighted: case ascertainment and bias, the distribution of allergic and irritant contact dermatitis in the working population, the interrelationship between exogenous (allergens, irritants) and endogenous factors, the prognosis, the social and economic impact, and the need for intervention studies.
International Archives of Occupational and Environmental Health, Nov. 1999, Vol.72, No.8, p.496-506. Illus. 75 ref.
Epidemiological research on work and health conditions in Spain
La investigación epidemiológica sobre condiciones de trabajo y salud en España [in Spanish]
Topics: computer applications; conditions of work; epidemiologic study; epidemiology; literature survey; occupational accidents; occupational diseases; occupational hygiene; research; Spain.
Instituto Nacional de Seguridad e Higiene en el Trabajo, c/Torrelaguna 73, 28027 Madrid, Spain, 1999. 45p. Illus. Bibl.ref.
Esmen N.A., Hall T.A., Stone R.A., Marsh G.M., Gula M.J., Gause C.K.
An investigation of secondary exposure misclassification effects of lifelong occupational history in exposure estimation
In most studies, only the direct effects of misclassification of the interpretation of results of occupational epidemiological studies are considered, or - alternatively - simple estimates of misclassification rates are assigned to various types of exposure estimation processes. Lifelong job profile data obtained from a previously published case-control study provided job histories of 511 decedents. An analysis of these work histories and the comparison of exposures related to longest-held job to estimated total lifetime exposures suggest that single job-based exposure estimates may lead to significant exposure misclassification rates. In addition, the appearance of shorter duration jobs in a study population occurring predominantly early in the work history may exacerbate problems associated with exposure misclassification. The inclusion of extensive recording of the work history of study subjects emerges as a reasonable basis for the investigation and potential reduction of secondary misclassification of exposures in occupational epidemiological studies.
American Industrial Hygiene Association Journal, Mar.-Apr. 1999, Vol.60, No.2, p.175-181. Illus. 16 ref.
Heederik D., Doekes G., Nieuwenhuijsen M.J.
Exposure assessment of high molecular weight sensitisers: Contribution to occupational epidemiology and disease prevention
Because exposure to high molecular weight sensitizers could only be evaluated indirectly, few studies have focused on establishing exposure-response relations, and exposure standards have not been established for high molecular weight sensitizers. Epidemiological studies in several industries that used immunoassay for exposure characterization have shown that risk of sensitization increases with increasing exposure to allergens. Several studies have also shown that clear differences in potency seem to exist. Sensitization to rat urinary allergens and fungal α-amylase occurred in the pg/m3 and ng/m3 range. The main research questions of the near future have to focus on the prevention of occupational sensitization. Standard-setting seems possible for some allergens on the basis of available scientific evidence for the existence of exposure response relations. However, assays for characterising exposure to allergens have to be rigorously standardized before they can be used under field conditions.
Occupational and Environmental Medicine, Nov. 1999, Vol.56, No.11, p.735-741. Illus. 52 ref.
Koh D., Seow A., Ong C.N.
Applications of new technology in molecular epidemiology and their relevance to occupational medicine
Technical advances in molecular biology are described which, combined with epidemiological methods, can shed light on understanding the biological processes associated with disease development. As end users, OEM practitioners should consider the impact of these advances on their practices. The availability of genetic tests to identify susceptible workers raises issues of ethics, individual privacy, right to work, and the relevance of such tests. Several studies have presented data on the association of environmental measurements and various biomarkers for internal and biologically effective dose, genetic polymorphisms, and early response markers. Given the limitations of individual molecular biomarkers in assessing risk to health, and the multifactorial nature of environmental disease, such an approach will increase understanding of the complex issue of mechanisms of disease and further refine the process of risk assessment.
Occupational and Environmental Medicine, Nov. 1999, Vol.56, No.11, p.725-729. 49 ref.
Carel R., Levitas-Langman A., Kordysh E., Goldsmith J., Friger M.
Case-referent study on occupational risk factors for bladder cancer in southern Israel
To evaluate the possible association between occupational exposure and male bladder cancer in the Negev region of southern Israel, 92 bladder cancer patients were studied by interview and compared with 92 males without oncological disease after matching by age and country of origin. The questionnaire was developed to gather information on demography, life-time occupational history, smoking habits, coffee consumption and health status, and the analysis of the data was performed by statistical methods. Significant associations were found between bladder cancer occurrence and occupational exposure to solvents, dusts and multiple chemicals; nephrolithiasis; and cigarette smoking. Certain types of occupational exposure, other than aromatic amines and dyes, may be considered as contributing factors in the epidemiology of bladder cancer.
International Archives of Occupational and Environmental Health, Aug. 1999, Vol.72, No.5, p.304-308. 29 ref.
Dell L.D., Mundt K.A., McDonald M., Tritschler J.P., Mundt D.J.
Critical review of the epidemiology literature on the potential cancer risks of methylene chloride
Literature survey with the aim of critically reviewing and summarizing the epidemiological evidence published to date on the carcinogenicity of dichloromethane to humans. Papers for review were identified through the US National Library of Medicine's Medline. Studies were classified according to three categories. Primary studies focused on the association between dichloromethane and cancer among occupational cohorts primarily exposed to dichloromethane. Secondary studies identified dichloromethane a priori as a potential exposure of interest, and which was either characterized or described for exposed workers separately. Tertiary studies evaluated cohorts either minimally exposed or presumed exposed to dichloromethane but for which no exposure estimation or separate classification was made. Continued follow-up of the established cohorts may elucidate the few and inconsistent relationships reported to date. However, it appears likely that risks associated with exposure, if any, are small and limited to rare cancers.
International Archives of Occupational and Environmental Health, Oct. 1999, Vol.72, No.7, p.429-442. 40 ref.
ADEREST - 5th Symposium on Epidemiology and Health at Work, Angers, 5 and 6 November 1998
ADEREST - 5e Colloque d'Epidémiologie en Santé et Travail, Angers, 5 et 6 novembre 1998 [in French]
Topics: age-linked differences; asthma; cancer; carbonaceous dust pneumoconiosis; 2-ethoxyethyl acetate; asbestos; catalase; conference; epidemiology; exposure evaluation; exposure tests; health hazards; hypertension; job-exposure relation; live work; medical supervision; mesothelioma; pesticides; screen printing; shift work; sickness absenteeism; sleep; social aspects; workplace design.
Revue de médecine du travail, Mar.-Apr. 1999, Vol.26, No.2, p.80-118. Illus. Bibl.ref.
Langholz B., Thomas D., Xiang A., Stram D.
Latency analysis in epidemiologic studies of occupational exposures: Application to the Colorado Plateau uranium miners cohort
A general statistical framework for modelling latency effects is described. Bilinear and exponential decay latency models are proposed and methods are described for fitting these models to cohort or case-control data. A latency analysis of radon exposure and lung cancer in the Colorado Plateau uranium miners cohort was performed. Analysis of the entire cohort showed that the relative risk associated with exposure increased for about 8.5 years and thereafter decreased until it reached background levels after about 34 years. The hypothesis that the relative risk remains at its peak level is strongly rejected. The variation in the latency effects over subsets of the cohort based on attained age, level and rate of exposure, and smoking was investigated. Age was the only factor for which effect modification was demonstrated. The decline in effect was much steeper at older ages than younger ages. The proposed methods can provide much more information about the exposure-disease latency effects than those generally used. Topics: age-linked differences; radon; case-control study; cohort study; epidemiology; hazard evaluation; latency; long-term exposure; lung cancer; mathematical models; uranium mining.
American Journal of Industrial Medicine, Mar. 1999, Vol.35, No.3, p.246-256. Illus. 28 ref.
Harrington J.M., Carter J.T., Birrell L., Gompertz D.
Surveillance case definitions for work related upper limb pain syndromes
A group of healthcare professionals from the disciplines interested in the prevention and management of upper limb disorders were recruited for a Delphi exercise. A questionnaire was used to establish case definitions from the participants, followed by a consensus conference involving the core group of 29 people. The draft conclusions were recirculated for review. Consensus case definitions were agreed for carpal tunnel syndrome, tenosynovitis of the wrist, de Quervain's disease of the wrist, epicondylitis, shoulder capsulitis (frozen shoulder) and shoulder tendonitis. The consensus group also identified a condition defined as "non-specific diffuse forearm pain" although this is essentially a diagnosis made by exclusion. The group did not have enough experience of the thoracic outlet syndrome to make recommendations. There was enough consensus among several health professionals from different disciplines to establish case definitions suitable for use in the studies of several work related upper limb pain syndromes. The use of these criteria should allow comparability between studies and centres and facilitate research in this field. The criteria may also be useful in surveillance programmes and as aids to case management.
Occupational and Environmental Medicine, Apr. 1998, Vol.55, No.4, p.264-271. 15 ref.
Shen N., Weiderpass E., Anttila A., Goldberg M.S., Vasama-Neuvonen K.M., Boffetta P., Vainio H.U., Partanen T.J.
Epidemiology of occupational and environmental risk factors related to ovarian cancer
Articles published during 1970-1997 from 48 epidemiologic studies on occupational and environmental risk factors of ovarian cancer are reviewed. The moderate amount of data on nurses, teachers, professionals, dry cleaning employees, women in agriculture, the pharmaceutical industry, pharmacists, waitresses, and cooks show very little, if any, evidence of excess risk. Hairdressers, beauticians, and women employed in the printing industry may be at increased risk, but the data are insufficient for strong conclusions. Few high-quality studies have been carried out and no chemical agents have been studied extensively, with the exception of exposure to talc. Ovarian cancer may have occupational and environmental etiologies intertwined with cultural, behavioral, and life-style factors and genetic susceptibility, but current knowledge is insufficient to quantify occupational and environmental aetiologies reliably.
Scandinavian Journal of Work, Environment and Health, June 1998, Vol.24, No.3, p.175-182. 98 ref.
Weiderpass E., Partanen T., Kaaks R., Vainio H., Porta M., Kauppinen T., Ojajärvi A., Boffetta P., Malats N.
Occurrence, trends and environmental etiology of pancreatic cancer
This review summarizes data on the occurrence, the trends, and the life-style, environmental, occupational and genetic determinants of pancreatic cancer. Epidemiologic evidence implicates tobacco smoking as one cause. The evidence regarding alcohol consumption is inconsistent. Although both positive and inconclusive findings are encountered, the bulk of the evidence on coffee consumption is negative. Fat intake is linked with obesity and diabetes mellitus, which are risk factors for pancreatic cancer. Fruit and vegetable consumption appears to be protective. No occupational or environmental agent has been confirmed to increase the risk, but epidemiologic evidence is inconsistent. Little is known about the role of genetic polymorphisms of metabolic enzymes in pancreas carcinogenesis, and evidence associating mutations with life-style factors is still scant and inconsistent.
Scandinavian Journal of Work, Environment and Health, June 1998, Vol.24, No.3, p.165-174. 215 ref.
Occupational epidemiology in agriculture: A case study in the Southern African context
Some challenges facing occupational epidemiology in developing countries are outlined in this case study of agriculture drawing on Southern African research. These include the characterization of exposures in resource- and data-poor environments typical of developing countries, the assessment of outcomes where cross-cultural and socio-environmental confounders may be substantial obstacles, and the impact of environmental exposures on workplace health. It is argued that, if occupational epidemiology is to have meaningful impact on the health of the most marginalized groups of workers in developing countries, it must redefine itself in terms of a public health approach. The boundaries of epidemiologic inquiry need to be broad, and amenable to interfacing with policy research, using qualitative methods and participatory approaches. More so than in other industrial settings, epidemiologists must move from research to practice, seeking to take action where interventions are needed, and to evaluate such actions. Topics: agriculture; child labour; confounding factors; developing countries; epidemiology; ethics; exposure evaluation; neurotoxic effects; pesticides; South Africa; women.
International Journal of Occupational and Environmental Health, Oct.-Dec. 1998, Vol.4, No.4, p.245-256. Illus. 47 ref.
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