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H Brenner

Publications and source records attributed to H Brenner.

At least 163 records · Page 9Linked to original sources
PubMed1996

Smoking patterns and mortality attributable to smoking in a cohort of 3528 construction workers.

This study describes the smoking patterns of 3528 construction workers as reported at occupational health examinations, in four occupational health centres located in the South of Germany, conducted between August 1986 and December 1988. Subjects were aged 20 to 59 years and were working as plumbers, carpenters, painters or varnishers, plasterers, bricklayers, unskilled workers or white collar employees. Overall smoking prevalence was 53.5%. It was considerably higher than in a representative population sample of the same age groups. Active follow up was carried out to ascertain vital status between October 1992 and July 1994. The effect of smoking on all cause mortality was assessed using the cox proportional hazard model. The relative risk of current smoking was 2.5 (95% CI 1.4-4.4) after adjustment for age, profession, self reported alcohol consumption, body mass index, nationality, and company size. 60% of the deaths among smokers and 34% of deaths in the whole cohort were attributable to smoking. These findings underline the need for comprehensive efforts to reduce smoking and its negative consequences in the occupational group.

Adult↗
PubMed1996

Parental smoking and sociodemographic factors related to smoking among German medical students.

Smoking among medical students has been found to vary strongly between European countries. Few studies have addressed factors associated with smoking among medical students within countries. In this study, we assessed the association of parental smoking and sociodemographic factors with smoking habits of medical students at the University of Ulm, Germany, Students who entered the 1st, 3rd and 5th year of medical school in fall 1992 were asked to complete a self-administered questionnaire. Questionnaires were returned by 696 (85.2%) of 817 eligible students. Overall, 23.7% of students were current smokers, and 11.9% were former smokers. Smoking habits were related to maternal smoking: Odds ratios for the association of maternal smoking with ever or current smoking of students were 2.11 (95% CI: 1.48-3.03) and 2.01 (95% CI: 1.35-3.01), respectively, after adjustment for potential confounders in multiple logistic regression. In contrast, no association was found between paternal smoking and students' smoking status. Male students were more likely to smoke than female students, and living in a large city during secondary school was also associated with ever smoking. No association was found between students' smoking habits and educational achievement of their mothers and fathers. These results suggest a key role of maternal smoking for smoking among medical students in this society.

Adult↗
PubMed1996

[Interrater reliability of instruments for the evaluation of needs of bedridden persons: a review of the international literature].

Objective and reliable rating of disability and functional dependence is of utmost importance for both medical and rehabilitation research and the practice of social medicine. The present paper provides an overview on internationally used disability scales and on studies that were carried out to determine their inter-rater reliability. Most of the scales were developed in the United States. The number and quality of inter-rater reliability studies strongly vary for various scales. In general, reliability was found to be high for summary scores of disability, whereas reliability strongly varied from extremely poor to excellent for single items of disability. This variation provides valuable suggestions for improving rating of disability.

Activities of Daily Living↗
PubMed1996

Smoking habits of future physicians: a survey among medical students of a south German university.

Physicians can play a key role in promoting abstinence from tobacco. In many European countries, however, a large proportion of physicians are still smoking themselves. To assess smoking habits of future physicians, a cross-sectional study was conducted in 1992/1993 among 817 students enrolled in the first, third, and fifth years of medical school at the university of Ulm, Germany, using a self-administered questionnaire. The overall participation rate was 85.2%. Prevalence of current smoking was 17.6% among female participants and 29.2% among male participants. Among male students, smoking prevalence varied between 22.9% in the first year and 34.6% in the fifth year of medical school. Among female students, there were only minor differences in smoking prevalence between the first, third and fifth years at medical school. Most of the smokers had started to smoke prior to entry into medical school. Among third and fifth year students, slightly more students quit smoking than started to smoke during medical school, and smokers in the fifth year of medical school were more frequently willing to quit than smokers in the first and third year. Factors associated with regular smoking of medical students, after adjustment for potential confounders in multivariable analysis, were age, sex, and maternal smoking. While smoking prevalence was somewhat lower in the present study than in previous studies from Germany, further efforts are needed to reduce smoking among future physicians in this country.

Adult↗
PubMed1996

Effects of misdiagnoses on disease monitoring with capture--recapture methods.

Capture--recapture methods are increasingly employed to correct for underascertainment of prevalent or incident cases in epidemiological surveillance. Routine systems of disease surveillance, such as morbidity registries or mortality statistics, are, however, often prone to errors in disease diagnosis. This article provides a quantitative assessment of the performance of the two-source capture--recapture method for disease monitoring in the presence of false-positive and false-negative diagnoses in one of the two sources. Expected capture--recapture case counts and traditional case counts are algebraically derived as functions of the individual case ascertainment probabilities of both sources and of the probabilities of diagnostic misclassification. It is shown that misdiagnoses can lead to underestimation or overestimation of case numbers by the capture--recapture approach, depending on the specific circumstances of disease monitoring. Nevertheless, the net bias is typically less severe than with traditional case counts. The findings are illustrated with examples from the field of cancer registration. Strategies are discussed that might minimize the problem of misdiagnoses in the design of capture--recapture studies or that might be used to correct for it in the analysis.

Death Certificates↗
PubMed1996

Measures of differential diagnostic value of diagnostic procedures.

Measures of validity of diagnostic procedures are commonly employed that quantify the ability of the procedures to distinguish individuals with and without a certain disease. These measures include, among others, the sensitivity and specificity, the likelihood ratios, and the positive and negative predictive value. In many clinical situations, however, the primary purpose of diagnostic procedures is to distinguish between two or more alternative diagnoses in addition to or rather than confirming or discarding a single diagnosis. This article presents a variety of measures that may be used to quantify the ability of a diagnostic procedure to distinguish between two among several alternative diagnoses. The measures are introduced algebraically, and their use is illustrated with hypothetical and empirical examples.

Diagnosis, Differential↗
PubMed1996

Dependence of weighted kappa coefficients on the number of categories.

Weighted kappa coefficients are commonly used to quantify inter- or intra-rater reliability or test-retest reliability of ordinal ratings in clinical and epidemiologic applications. In this paper, we assess the dependence of weighted kappa coefficients on the number of categories and the type of weighting scheme, which vary between applications. The most commonly used weights are weights that are proportional to the deviation of individual ratings ("linear weights") or to the square of the deviation of individual ratings ("quadratic weights"). Quadratically weighted kappa coefficients are equivalent to the intraclass correlation coefficient and to the product-moment correlation coefficient under certain conditions. We illustrate that an increase of quadratically weighted kappa coefficients with the number of categories is expected under a broad variety of conditions, whereas linearly weighted kappa coefficients appear to be less sensitive to the number of categories. Number of categories and type of weighting scheme therefore require careful consideration in the interpretation of weighted kappa coefficients.

Data Interpretation, Statistical↗
PubMed1996

Correcting for exposure misclassification using an alloyed gold standard.

Validation studies are increasingly employed to estimate and correct for exposure misclassification in epidemiologic studies. Often, however, the reference procedure used for validation is less than perfect. This phenomenon may lead to biased estimates of misclassification rates and hence of "corrected" measures of associations. In particular, it has been demonstrated that basic matrix correction procedures to correct for presumably nondifferential exposure misclassification may yield strongly misleading results in the case of an imperfect gold standard. The problem arises because apparent misclassification (misclassification with respect to an alloyed gold standard) is often differential even if true misclassification (misclassification with respect to true exposure status) is nondifferential. Therefore, correction procedures for differential rather than nondifferential misclassification should be employed in the presence of an alloyed gold standard.

Bias↗
PubMed1996

Older workers in the construction industry: results of a routine health examination and a five year follow up.

OBJECTIVE: To describe the health status of older construction workers and the occurrence of early retirement due to disability or of mortality within a five year follow up. METHODS: Firstly, a cross sectional study was performed among 4958 employees in the German construction industry, aged 40-64 years, who underwent standardised routine occupational health examinations in 1986-8. The study population included plumbers, carpenters, painters/varnishers, plasterers, unskilled workers, and white collar workers (control group). Job specific prevalence and age adjusted relative prevalence were calculated for hearing loss, abnormal findings at lung auscultation, reduced forced expiratory volume, increased diastolic blood pressure, abnormalities in the electrocardiogram, increased body mass index, hypercholesterolaemia, increased liver enzymes, abnormal findings in an examination of the musculoskeletal system, and abnormalities of the skin. Secondly, follow up for disability and all cause mortality was ascertained between 1992 and 1994 (mean follow up period = 4.5 y). Job specific crude rates were calculated for the occurrence of early retirement due to disability and for all cause mortality. With Cox's proportional hazards model, job specific relative risks, adjusted for age, nationality, and smoking were obtained. RESULTS: Compared with the white collar workers, a higher prevalence of hearing deficiencies, signs of obstructive lung diseases, increased body mass index, and musculoskeletal abnormalities were found among the construction workers at the baseline exam. During the follow up period, 141 men died and 341 men left the labour market due to disability. Compared with white collar workers, the construction workers showed a 3.5 to 8.4-fold increased rate of disability (P < 0.05 for all occupational groups) and a 1.2 to 2.1-fold increased all cause mortality (NS). CONCLUSIONS: This study shows the need and possibilities for further health promotion in workers employed in the construction industry, targeting both work related conditions and personal lifestyle factors. Rehabilitation measures should be enforced to limit the rate of disability among construction workers.

Adult↗
PubMed1996

[Differences in application and granting benefits for severely disabled patients before and after introduction of new benefits within the scope of the public health reform law].

Constituting part of the health reform in Germany ("Bundesgesundheits-Reformgesetz"), an extension of health insurance benefits for severely disabled persons was introduced in 1991. The assessment of eligibility for benefits is based on standardised medical examinations. Examinations performed in the state of Baden-Württemberg in 1990 (n = 6401) were compared with a 20% random sample of those performed in 1991 (n = 7563) in order to analyse eventual changes in acceptance rates of applications. Acceptance rates decreased from 87.9% in 1990 to 70.8% in 1991. The difference could not be explained by differences in age, sex, medical diagnosis or dependence on help in daily activities. This suggests that acceptance criteria were less restrictive before introduction of the extension of benefits.

Adolescent↗
PubMed1996

[Requirements and provision of services for severely handicapped patients according to SGBV regulations 1991-1993].

Benefits for non-institutionalised severely disabled persons by the German statutory health insurance system were introduced in 1989 and extended in 1991. They were provided depending upon a standardised medical examination. We analysed 4185 examinations carried out in the city and the region of Augsburg in Southern Germany during 1991-1993 with regard to social and medical conditions of applicants. A total of 2706 persons examined (64.7%) were considered to meet the criteria of permanent dependence on nursing. The majority of applicants were more than 75 years of age (56.9%) even though all age groups were represented. The leading cause for dependence on nursing were diseases of the circulatory system (29.4%), followed by diseases of the nervous system (20.5%) and musculoskeletal disorders (14.6%). The main burden of nursing care was borne by the relatives; professional institutions played only a minor role. The degree of dependence with regard to basic activities of daily living, especially "turning in bed", "dressing" and "using toilet" showed the strongest association with the overall assessment of nursing dependence. With the introduction of a new nursing care insurance system in Germany ("Pflegeversicherung") in January 1995, benefits for disabled persons have been extended further. To improve prevention of nursing-care dependence and to ensure the best possible care of patients in need of such care, further investigations are required which should focus on risk factors for both nursing-care dependence and long-term nursing home and hospital admission of disabled persons.

Activities of Daily Living↗
PubMed1996

[Empirical analysis of expert social medicine assessment of disability based on the decision of the Federal social court].

Objective assessment of need for nursing care should be based on well defined criteria. In 1993, the Federal German Social Court ("Bundessozialgericht", BSG) has given criteria for identifying individuals in permanent need of very intensive nursing care ("Schwerpfledgebedürftige"), who qualified for benefits granted by the Germany statutory health insurance system at that time. The criteria were primarily based on the number of activities of daily living for which the applicants were in need of help. The criteria were largely, but not entirely, consistent with previously established criteria employed by the Medical Service of the Health Insurances ("Medizinischer Dienst der Krankenversicherung", MDK), who was responsible for the assessment. An analysis of 4185 examinations carried out by MDK in the region of Augsburg in 1991-1993 showed that the majority of judgments were in agreement with the criteria given by BSG. However, individuals with psychiatric disorders or symptoms were often rated by MDK as being in permanent need of very intensive nursing care even if BSG criteria were not fulfilled. Exclusive judgement of nursing dependency on the basis of single activities of daily living appears to be inadequate for this group of persons.

Activities of Daily Living↗
PubMed1996

Effects of disease-dependent changes of exposure in cross-sectional studies.

The possibility of disease-related changes in exposure is a major limitation of many epidemiologic studies. This limitation particularly applies to cross-sectional studies, in which exposure and presence of disease are measured at the same point of time. In some cross-sectional studies, attempts are made to collect information not only on current exposure, but also on exposure at some period in the past. Various methods have been proposed to assess the relation of past and current exposure with disease in such situations. Systematic methodologic work is lacking, however, on the performance of these methods in the presence of disease-related changes of exposure. In this paper, we provide a model to assess the effects of such changes, and we illustrate the effects with a variety of numerical examples. We show that all of the proposed methods can yield seriously biased measures of current exposure effects in the presence of disease-related changes in exposure, and we illustrate the direction and order of magnitude of the biases. Our results imply that there is usually no alternative to longitudinal approaches to measure exposure in relation to disease onset if disease-related changes of exposure are of concern.

Bias↗
PubMed1996

Determinants of homonym and synonym rates of record linkage in disease registration.

Reliable record linkage is an essential component of the quality of population-based disease registration. Quality assessment of disease registries should, therefore, include quantitative approaches to describe the extent of record-linkage errors. The homonym and synonym rates have been proposed for this purpose. The homonym rate quantifies the proportion of distinct patients excluded from registration due to erroneous linkage with other patients. The synonym rate quantifies the proportion of unrecognized duplicate notifications on patients already registered in the registry. This paper provides an algebraic assessment of the determinants of both rates. It is shown how the homonym and the synonym rate are determined by the discriminating power provided by the personal identifiers and the record-linkage procedure on the one hand and the specific circumstances of disease registration on the other hand, such as the number of patients in the registry or the number of notifications per case. All these factors should be taken into account when reporting and interpreting results of record-linkage studies, particularly if comparisons are made between the performance of record-linkage procedures in different environments.

Data Interpretation, Statistical↗
PubMed1995

Alternative approaches for estimating prevalence in epidemiologic surveys with two waves of respondents.

Estimates of prevalence in epidemiologic surveys are prone to bias due to selective response. Therefore, much effort is devoted to reduce the number of nonrespondents. For example, individuals who do not respond in the first round of recruitment in mail surveys are usually contacted a second (or even third or fourth) time yielding consecutive waves of responses. Yet this sequence of waves is often neglected in epidemiologic analyses in that prevalence is simply estimated as the proportion of trait-positive individuals among the total group of respondents. This paper investigates alternative estimates of prevalence that might be used in surveys with two waves of respondents. The estimates are based on different assumptions on the relation of response rates with the trait of interest. As this relation is likely to vary from survey to survey depending on the specific circumstances under which the recruitment of participants is conducted, none of the estimates is universally preferable. The performance of the different estimates is assessed in a variety of hypothetical and empirical examples, and strategies are discussed to make the best use of the different estimates in the analysis of epidemiologic studies.

Bias↗
PubMed1995

Familial cutaneous malignant melanoma and tumors of the nervous system. A hereditary cancer syndrome.

BACKGROUND: Excessive risk of cutaneous melanoma as a second cancer has been associated with benign or malignant tumors of the nervous system. Cutaneous melanoma and nervous system tumors may independently aggregate in families. There are, however, no previous reports of increased likelihood of tumors of the nervous system in families of patients with cutaneous melanoma or--of cutaneous melanoma in families with tumors of the nervous system. METHODS: The occurrence of nervous system tumors as second cancers was examined in a series of 904 patients with cutaneous melanoma and/or their family members. RESULTS: Fifteen families with 17 members with cutaneous melanoma from this series had one or more additional relatives with tumors of the nervous system, including astrocytoma, medulloblastoma, glioblastoma multiforme, ependymoma, glioma, meningioma, and acoustic neurilemmoma. Another subgroup of 10 patients with cutaneous melanoma had either a meningioma (n = 9) or acoustic neurilemmoma (n = 1) as a second tumor. The pattern of atypical melanocytic nevi occurring in the majority (20/25) of cutaneous melanoma patients in our series and in additional first degree relatives of 9 of 11 of the affected families, has been previously associated with the Familial Atypical Multiple Mole-Melanoma syndrome. CONCLUSIONS: This unusual familial and personal occurrence of tumors, showing differentiation toward tissues of the neural crest, neuroepithelium, and/or mesenchymal derivation, supports a putative association with a hereditary cancer susceptibility trait.

Adolescent↗
PubMed1995

Detection efficiency of colorectal carcinoma recurrence using technetium pertechnetate-anti-carcinoembryonic antigen monoclonal antibody BW 431/26.

BACKGROUND: A new anti-carcinoembryonic antigen (CEA) antibody, BW 431/26 (Scintimun, Behring-Werke, Marburg, Germany), labeled with technetium pertechnetate (Tc-99m), is an intact immunoglobulin G1 monoclonal antibody that has been used to image colorectal cancer (CRC). This report is part of a prospective multicenter clinical trial initiated by the International Atomic Energy Agency to evaluate the role of this antibody in radioimmunoimaging of patients with suspected disease recurrence. METHODS: A group of 31 consecutive patients underwent radioimmunoimaging with Tc-99m-BW 431/26 after resection of their primary CRC. Patient referral was based on either a persistent rise in serum CEA levels of unknown origin and/or questionable findings by other imaging studies. Whole-body planar scans and single photon emission computed tomography scans of selected body regions (e.g., chest, abdomen) were performed up to 24 hours after the intravenous antibody injection. Pathologic antibody concentration localizations by radioimmunoimaging were correlated with surgical, clinical, and other imaging modality findings to validate the accuracy of radioimmunoimaging in detecting CRC recurrence. RESULTS: A total of 75 detected tumoral lesions was evaluated: 26 of 75 were of known origin (36%), and 49 of 75 were of unknown origin (65%). There were four true-negative lesions, one false-negative lesion, and no false-positive lesions; all others were true-positive lesions. Sensitivity was 96.8%, specificity 100%, and accuracy 98.6%. The study was easy to perform, without untoward side effects on patients after antibody administration. CONCLUSIONS: Anti-CEA antibody radioimmunoimaging is a highly reliable diagnostic procedure in detecting CRC recurrence and is useful especially for the diagnosis of patients with rising CEA blood levels of unknown origin, thereby significantly affecting patient management. Radioimmunoimaging should become part of the diagnostic workup of patients suspected of having CRC recurrence.

Aged↗