Thomas Behrens

Are asthma and allergies in children and adolescents increasing? Results from ISAAC phase I and phase III surveys in Münster, Germany.

Objective: To assess time trends in symptoms of asthma, allergic rhinitis, and atopic eczema among children in Münster, Germany.

Knowledge and perception of guidelines and secondary prevention of coronary heart disease among general practitioners and internists. Results from a physician survey in Germany

Aims This study investigated knowledge and perception of guidelines in secondary prevention of coronary heart disease and the impact of guideline knowledge on treatment practices in coronary patients among primary care physicians. Design and methods A representative questionnaire survey was performed in 2002–2003 among all 1023 general practitioners and office-based internists in the Region of Münster, Germany. The survey instrument contained questions on knowledge and attitudes toward guidelines, risk factors and treatment practices in secondary prevention of coronary heart disease. Results In total, 681 (66.6%) physicians participated. Seventy percent of physicians reported knowledge of at least one guideline. Participants expressed mainly positive attitudes toward guidelines but also reported important barriers to their implementation such as lack of reimbursement. Only 63 and 32%, respectively, reported to start antihypertensive and lipid-lowering treatment according to guidelines. Physicians reporting guideline knowledge were more likely to initiate lipid-lowering treatment of elevated low-density lipoprotein (LDL)-cholesterol [odds ratio (OR) 2.3; 95% confidence interval (CI) 1.5–3.5], to intensively advise overweight patients (OR 1.5; 95% CI 1.0–2.5), to make use of nicotine replacement therapy or cessation courses in smoking patients (OR 1.7; 95% CI 1.2–2.4), and to comply with an overall measure of guideline adherence (OR 1.8; 95% CI 1.1–2.8). Conclusions In this study, guideline knowledge led to improved cardiovascular risk factor treatment among GPs and internists. Many physicians, however, do not treat coronary patients according to evidence-based guidelines. Further dissemination of guidelines and educational efforts are essential to improve secondary prevention of coronary heart disease.

Predictors of health care utilization of children with asthma in the community.

The aim of this study was to assess the pattern of use of health care services among children with asthma symptoms within the community, and assess groups at increased risk of emergency department (ED) visits or hospital admissions (HA). Using International Study of Asthma and Allergies in Childhood phase II protocol, information about asthma management and utilization of health care services was collected by parental questionnaire in a community‐based random sample of 5–7‐ and 9–11‐year‐old children (n = 11,094) in Dresden and Munich. Only 11.2% of children with current wheeze did not utilize any health care facility or consultation for their asthma symptoms in the 12 months prior to survey, while 86.2%, 12.3%, and 3.6% had at least one asthma related physicians consultation, ED visits, or HA, respectively. Predictors of ED visits and HA among current wheezers were: younger age, male gender, speech‐limiting wheeze, level of exposure to environmental tobacco smoke. In addition, children of low socioeconomic status were more likely to have ED visits because of their asthma. Childhood asthma is a major public health problem in Germany leading to substantial morbidity and utilization of health care services. Exposure to tobacco smoke comes out as the major modifiable risk factor related to asthma morbidity in children.

Symptoms of Asthma and the Home Environment. The ISAAC I and III Cross-Sectional Surveys in Münster, Germany

Background: The indoor home environment has been shown to be associated with the presence of respiratory symptoms and atopic disease. Methods: Two cross-sectional surveys (1995–2000) were conducted, using data from the ISAAC phase I and III surveys, collected in Münster, Germany (n = 6,996, response 81.8%). We analyzed the prevalence ratio (PR) for several indoor exposures and asthma-related outcomes in 6- to 7-year-old children, adjusting for potential confounders. Results: Positive associations were observed regarding exposure to molds, environmental tobacco smoke, cooking with gas and space heating with fossil fuels, but most associations were not statistically significant. Surprisingly, presence of a carpet was negatively associated with most respiratory conditions. When restricting the analysis to participants without avoidance of a carpet due to a history of atopic disease, the protective associations disappeared. Mostly, present pet ownership did not show positive associations with respiratory symptoms. However, ownership at different times in life revealed positive associations, particularly in regard to birds owned in the first year of life (PR 1.51, 95% CI 1.11–2.06, for sleep disturbance due to wheeze and PR 1.28, 95% CI 1.01–1.63, for wheeze during the last 12 months, respectively). Conclusions: Only few indoor factors were positively associated with the studied outcomes. The change of associations in participants that reported allergy-related avoidance of carpets suggests that the observed effects are a result of asthmatics’ changed behavior. The effect of allergy-related change in behavior and the results observed concerning the ownership of pets at different ages underline the need of establishing a precise temporal relationship between disease and exposure.

Self-reported traffic density and atopic disease in children. Results of the ISAAC Phase III survey in Muenster, Germany.

Positive associations between traffic exposure and atopic respiratory disorders in children have been described in several studies. We analyzed data related to self‐reported truck traffic density and several symptoms and diagnoses of asthma and hay fever (12‐month wheezing and rhinitis symptoms, diagnoses of asthma and hay fever) from the ISAAC Phase III survey in Muenster, Germany, using core written and video questionnaires. Data were collected from representative school‐based samples (n = 7345) of 6–7‐ and 13–14‐yr‐olds. In 13–14‐yr‐olds, according to exposure levels categorized into rare, frequent, and constant, with the ‘never’‐category used as reference, the sex‐adjusted prevalence ratios were 1.29 (95% CI = 1.08–1.53), 1.58 (1.29–1.94), and 1.57 (1.18–2.10) for wheeze in the past 12 months, and 1.20 (1.06–1.34), 1.35 (1.17–1.55), and 1.69 (1.42–2.0) for rhinitis symptoms in the past 12 months. Prevalence ratios in 6–7‐yr‐olds and results for a diagnosis of asthma were less consistent while no positive association was detected between hay fever and truck traffic in both age groups. When analyses were based on a more general traffic indicator (self‐reported traffic noise), no consistent associations were observed. Our data provide support for the hypothesis that residential exposure to truck traffic may adversely affect the health of children.

Sharing the knowledge gained from occupational cohort studies: A call for action

Objectives An immense body of knowledge has been created by establishing various job-exposure matrices (JEMs) to assess occupational exposures in community- and industry-based cohort studies. These JEMs could be made available to occupational epidemiologists using knowledge-sharing technologies, thereby saving considerable amounts of time and money for researchers investigating occupation-related research questions. In this paper, the authors give an example of how a detailed JEM can be easily transformed into a job-specific module (JSM) for use in community-based studies. Methods OccIDEAS is operationalised as a web-based software, combining the use of JSMs with an individual expert exposure assessment to assess occupational exposures in various industries according to a set of predefined rules. The authors used a JEM focusing on endocrine-disrupting chemicals from a German study on testicular cancer in the automobile industry to create a JSM in OccIDEAS. Results The JEM was easily translated into OccIDEAS requiring about 50 h of work by an epidemiologist familiar with the German JEM to learn about the OccIDEAS structure, establish the required set of exposure rules and to translate the JEM into OccIDEAS. Language did not represent an obstacle for translation either. To make the data available in an international context, an interpreter had to translate the German tasks and exposures after they were coded into OccIDEAS. Conclusions JEMs which are constructed based on identifying tasks that determine exposure can be easily transformed into a JSM. Occupational epidemiologists are invited to contribute to the international scope of OccIDEAS by providing their previously established JEMs to make existing data on occupational exposures widely available to the epidemiological community.

Exposure to metal-working fluids in the automobile industry and the risk of male germ cell tumours.

Introduction In a previous analysis of a case–control study of testicular cancer nested in a cohort of automobile workers, we observed an increased risk for testicular cancer among workers who had ever been involved in occupational metal-cutting tasks. We investigated whether this risk increase was due to exposure to metal-working fluids (MWF). Methods Occupational exposure to MWF was assessed in detail using a job-specific questionnaire for metal-cutting work. We calculated ORs and associated 95% CIs individually matched for age (±2 years) and adjusted for a history of cryptorchidism by conditional logistic regression. Results The prevalence of exposure to MWF was 39.8% among cases and 40.1% among controls. For total germ cell tumours and seminomas we did not observe risk increases for metal-cutting tasks or occupational exposure to MWF (OR 0.95; 95% CI 0.69 to 1.32 and OR 0.88; 95% CI 0.58 to 1.35, respectively). However, dermal exposure to oil-based MWF was associated with an increased risk for non-seminomatous testicular cancer. Dermal exposure to oil-based MWF for more than 5000 h showed particularly high risk estimates (OR 4.72; 95% CI 1.48 to 15.09). Discussion Long-term dermal exposure to oil-based MWF was a risk factor for the development of non-seminomatous testicular germ cell cancer. Possible measures to reduce exposure include the introduction of engineering control measures such as venting or enclosing of machines, and enforcing the use of personal protective equipment during metal cutting.

Barriers to guideline implementation.

In order to investigate the high prevalence of cardiovascular risk factors in the Munster area that is still observed in spite of existing guidelines for secondary prevention of coronary heart disease (1) we conducted the COSIMA study from 2002–2004 at the Institute of Epidemiology and Social Medicine at the University of Munster (2). We asked 1023 practicing physicians organized in the administrative district of Munster of the Westphalia-Lippe Medical Association about the most important cardiovascular risk factors and about their knowledge and acceptance of guidelines in secondary coronary prevention. Our results confirm the findings described in the article (3)—namely, a higher acceptance of guideline-based medicine and a better knowledge and acceptance of guidelines among younger colleagues, internists, and doctors who take part in quality circles. However, our results also indicate important barriers to guideline implementation. The majority of physicians primarily named organizational factors, such as a lack of reimbursement (84% agreement) and lack of time (51% agreed). Furthermore, poor patient compliance (70%) and contradictory recommendations in guidelines published by different medical societies (54%) were stated. The main criticisms of guidelines as an instrument of evidence-based medicine again focused on cost reduction and a perceived lack of flexibility in the treatment of patients. In order to successfully implement guidelines in medical practice, a multi-level approach seems to be crucial. Local settings and circumstances, private physicians’ values, and perceived barriers could be discussed by audits in the context of local quality circles in order to develop strategies for a better guideline implementation. The acceptance of guideline recommendations by treating physicians is of critical importance, and may be achieved by publishing guidelines of high scientific quality and transparency.

The Use of Synthetic Bedding in Children. Do Strategies of Change Influence Associations with Asthma

Background. Epidemiological data suggest in contrast to clinical recommendations a negative effect of synthetic bedding on asthma and respiratory symptoms. Objective. To assess the effects of bedding filled with synthetic material on the risk of asthma and respiratory symptoms in 6- to 7-year-old children, taking into account allergy-related change of bedding material. Methods. We analyzed data from the ISAAC Phase III cross-sectional survey (1999/2000) in Münster, Germany. Data were collected by parental report from representative school-based samples of 6- to 7-year old children (n = 3,529). We calculated prevalence ratios with 95% confidence intervals for the association between respiratory symptoms suggestive of asthma and synthetic pillows and blankets and adjusting for potential confounders. Results. In the preliminary analyses, synthetic pillows and synthetic blankets were positively associated with the studied respiratory outcomes. For example, a high number of wheezing attacks was positively associated with synthetic pillows (PR = 4.44; 95% CI 2.84–6.94) and synthetic blankets (PR = 3.80; 95% CI 2.48–5.82). However, in the restricted analysis, excluding participants reporting allergy-related change of bedding (pillows n = 440; blankets n = 437), the positive associations disappeared for all studied outcomes. Conclusions. Our findings suggest that allergy-related choice of bedding is an important factor in the assessment of the relation between synthetic bedding and asthma symptoms. Ignoring those changes can lead to false-positive risk estimates. Prospective studies that allow to disentangle the temporal sequence of disease, exposure, and change of bedding should help to further clarify this issue.

Exposure assessment in epidemiological studies: what has to be considered when comparing job-exposure matrices?

In a recent article, Offermans et al studied the agreement of three job-exposure matrices (JEM) in the Netherlands Cohort (NLCS) with respect to asbestos, polycyclic aromatic hydrocarbons (PAH) and welding fume exposure.1 The studied JEMs were quite different in their approach to assess exposure: one was based on prevalent mesothelioma cases in jobs highly exposed to asbestos (Asbestos-JEM), the second one (FINJEM) used time-dependent continuous values based on expert assessment and measurement data, and the third (DOMJEM) was a semi-quantitative expert-based JEM that assigned exposure scores (0, 1, 2) to job titles without consideration of change of exposure levels over time. Thus time-dependent exposure levels are not available for the DOMJEM. Using …