Biomedical subjects

C E Minder

Publications and source records attributed to C E Minder.

At least 19 recordsLinked to original sources

PubMed2001

Leukemia, brain tumors, and exposure to extremely low frequency electromagnetic fields in Swiss railway employees.

Railway engineers provide excellent opportunities for studying the relation between exposure to extremely low frequency magnetic fields and leukemia or brain tumors. In a cohort study of Swiss railway personnel with 2.7 x 10(5) person-years of follow-up (1972--1993), the authors compared occupations with high average exposures (line engineers: 25.9 microT) to those with medium and low exposures (station masters: 1 microT). The mortality rate ratio for leukemia was 2.4 (95% confidence interval (CI): 1.0, 6.1) among line engineers (reference category: station masters). The mortality rate ratio for brain tumors was 1.0 (95% CI: 0.2, 4.6) among line engineers and 5.1 (95% CI: 1.2, 21.2) among shunting yard engineers (compared with station masters). Two exposure characteristics were evaluated: cumulative exposure in microT-years and years spent under exposure to magnetic fields of > or =10 microT. There was a significant increase in leukemia mortality of 0.9% (95% CI: 0.2, 1.7) per microT-year of cumulative exposure to extremely low frequency magnetic fields. The increase by years spent under exposure of > or =10 microT was even stronger: 62% per year (95% CI: 15, 129). Brain cancer risk did not show a dose-response relation. This study contributes to the evidence for a link between heavy exposure to extremely low frequency magnetic fields and leukemia. Its strengths include reliable measurements and reliable historical reconstruction of exposures.

Adult↗

PubMed2001

[Test-retest reliability of a German language multidimensional assessment instrument in elderly probands].

Most geriatric assessment instruments have been developed in the English language. Translated versions might differ in their psychometric properties. We analyzed the test-retest reliability and internal consistency of a German instrument for multidimensional geriatric assessment that was based on a newly developed English version. A group of 100 over 75-year-old community-dwelling persons (mean age 83.0 years, 81% women) in Hamburg (n = 26) and Ulm (n = 51), Germany, and Berne (n = 23), Switzerland was interviewed twice by the same trained interviewers with a one week interval. We administered questions on general health, chronic disorders, basic and instrumental activities of daily living, urinary incontinence, nutrition, falls, pain, the social support/network and preventive care measures. In addition, the Functional Status Questionnaire, the Physical Activity Scale for the Elderly, the Geriatric Oral Health Assessment Index, the Visual Function Questionnaire, the Hearing Handicap Inventory for the Elderly and the Geriatric Depression Scale were administered. Cohen's kappa was good to excellent (0.64 < or = kappa < or = 0.89) with only three exceptions (pain questions, kappa = 0.53; questions on preventive care services, kappa = 0.51; and one of the questions on recent falls, kappa = 0.44). Cronbach alpha (internal consistency) was good to excellent for all domains (0.76 < or = alpha < or = 0.95). The study results confirm good test-retest reliability of the German version of this multidimensional geriatric assessment instrument. Adapted versions of this instrument can be used for different purposes, e.g., preventive home visits, outpatient geriatric assessments or epidemiological studies in older persons.

Activities of Daily Living↗

PubMed2000

A randomized trial of in-home visits for disability prevention in community-dwelling older people at low and high risk for nursing home admission.

BACKGROUND: In-home preventive visits with multidimensional geriatric assessments can delay the onset of disabilities in older people. METHODS: This was a stratified randomized trial. There were 791 participants, community-dwelling people in Bern, Switzerland, older than 75 years. The participants' risk status was based on 6 baseline predictors of functional deterioration. The intervention consisted of annual multidimensional assessments and quarterly follow-up in-home visits by 3 public health nurses (nurses A, B, and C), who, in collaboration with geriatricians, evaluated problems, gave recommendations, facilitated adherence with recommendations, and provided health education. Each nurse was responsible for conducting the home visits in 1 ZIP code area. RESULTS: After 3 years, surviving participants at low baseline risk in the intervention group were less dependent in instrumental activities of daily living (ADL) compared with controls (odds ratio, 0.6; 95% confidence interval, 0.3-1.0; P = .04). Among subjects at high baseline risk, there were no favorable intervention effects on ADL and an unfavorable increase in nursing home admissions (P= .02). Despite the similar health status of subjects, nurse C identified fewer problems in the subjects who were visited compared with those assessed by nurses A and B. Subgroup analysis revealed that among low-risk subjects visited by nurses A and B, the intervention had favorable effects on instrumental ADL (P = .005) and basic ADL (P = .009), reduced nursing home admissions (P = .004), and resulted in net cost savings in the third year (US $1403 per person per year). Among low-risk subjects visited by nurse C, the intervention had no favorable effects. CONCLUSIONS: These data suggest that this intervention can reduce disabilities among elderly people at low risk but not among those at high risk for functional impairment, and that these effects are likely related to the home visitor's performance in conducting the visits.

Activities of Daily Living↗

PubMed2000

Health services utilization of elderly Swiss: evidence from panel data.

The demand for health care services by the elderly is a topic of growing importance because of changes in the demographic structure in many countries. This paper provides estimates of the determinants of the demand for physician visits by the elderly, including the impact of a disability prevention intervention. We control for unobserved heterogeneity across individuals and the count data structure of the data by estimating random effects negative binomial models for all primary physician and specialist visits.

Aged↗

PubMed2000

[A multidimensional questionnaire as a component of preventive geriatric assessment: comparison of self-assessment version with the interview version].

In an earlier study we have shown good internal consistency and test-retest-reliability of a newly developed German-language instrument in the interviewer-administered version. The aim of this study was to test the reliability of a self-administered version compared to the original interviewer-administered version of our newly developed German-language instrument. We recruited a group of 50 over 75-year-old community-dwelling persons in Hamburg, Germany (N = 25) and Berne, Switzerland (N = 25). The questionnaire contains items on: self-perceived health, chronic conditions, basic and instrumental activities of daily living, urinary incontinence, nutrition, recent falls, pain, the social support/network and preventive-care measures. In addition, the Functional Status Questionnaire, the Physical Activity Scale for the Elderly, the Geriatric Oral Health Assessment Index, the Visual Function Questionnaire, the Hearing Handicap Inventory for the Elderly and the Geriatric Depression Scale were administered. Cohen's Kappa (self-administered version compared to the interviewer-administered version) was good to excellent (0.69-1.0) with only three exceptions (physical activity kappa = 0.49, basic activities kappa = 0.54 and oral health kappa = 0.54). For the domains activities of daily living, oral health, visual function and depression the self-administered version detected significantly more problems than the interview. In the future the self-administered version of this assessment instrument can be used for various purposes, e.g. (annual) preventive geriatric assessment for outpatients and other community-dwelling persons and epidemiological studies in older persons.

Activities of Daily Living↗

PubMed2000

[Preventive home visits for elderly patients: development and pilot testing of a multidimensional assessment instrument].

Preventive home visits with multidimensional geriatric assessment have been shown to delay or prevent the onset of disability and reduce nursing home admissions in older people. The purpose of the present study was to develop and test a multidimensional instrument for in-home preventive assessments in older persons. In developing the instrument, we conducted a systematic literature review of risk factors for functional status decline and of appropriate instruments for measuring these risk factors. Based on an Expert Panel using a modified Delphi process [1] the risk factor domains for functional status decline were chosen, [2] the instruments for evaluating each of the included risk factor domains were selected, and [3] the individual instruments were combined into one comprehensive assessment instrument. A German language version of the original English version of the instrument was developed based on translation, backtranslation, and cultural adaptation. The feasibility of use of the new instrument was evaluated in a field test in 150 people aged 75 years and older in Hamburg, Ulm, Germany, and Bern, Switzerland. The instrument was well accepted by the older persons. The prevalence of risk factors for functional status decline in these populations (e.g., physical inactivity, urinary incontinence, vision impairment) was high. There was also a high prevalence of underuse of preventive care measures (e.g., no pneumococcal vaccination in over 95 percent of persons). These preliminary results support the possible usefulness of this instrument for conducting preventive home visits or for epidemiological purposes (e.g., prevention surveillance). In a next phase, the test-retest reliability of the instrument, and the feasibility and reliability of self-administration as compared to interviewer administration will be described in a separate paper.

Aged↗

PubMed1998

Comparison of responses to an asthma symptom questionnaire (ISAAC core questions) completed by adolescents and their parents. SCARPOL-Team. Swiss Study on Childhood Allergy and Respiratory Symptoms with respect to Air Pollution.

The primary objective of the study was to determine the impact of the identity of the respondent (parents versus adolescents) on prevalence estimates of asthma symptoms in Swiss adolescents. In addition, factors influencing agreement between parents' and adolescents' responses to the same questions were analysed. One thousand three hundred and seventy-four (78.4%) adolescents, aged 14 years, self-completed a questionnaire at school based on the International Study of Asthma and Allergy in Childhood (ISAAC) core questions on wheezing and asthma. The same questions were incorporated into a questionnaire to be completed by the parents at home. The adolescents' self-reported prevalence rates of current asthma symptoms and "asthma ever" were significantly higher than those obtained from the parental questionnaires. 856 (62.6%) parental questionnaires were filled in by parents without the help of the adolescents, 460 (37.4%) were completed by parents and adolescents and 51 (3.7%) were completed by the adolescents without the parents. Prevalence rates were higher when parents and adolescents completed the questionnaire jointly than when questionnaires were completed by parents alone. The level of agreement between parental and self-completed questionnaires was moderate to low (kappa coefficients 0.22-0.68). Agreement between parental and adolescents reports of asthma symptoms was best when questionnaires were completed jointly by parents and adolescents, when the adolescent was a girl, when a family history of asthma was recorded, when the adolescent was a non-smoker, and when the parental education was high. We conclude that the higher reporting of prevalence rates of current asthma symptoms by adolescents compared to reporting by their parents demonstrates the need to take the respondent to a questionnaire into account when comparisons are made between prevalence studies. The results also suggest that factors related to the family milieu influence symptom reporting.

Adolescent↗

PubMed1998

Are safety committees really safe?

In an increasing number of recent major clinical trials, independent safety committees or safety monitors have been involved. Their role and function is not yet defined and continues to evolve. The aim of this paper is to discuss the role and tasks of safety committees as a result of our collective experience as members of three safety committees of studies evaluating antithrombotic prophylaxis against postoperative deep vein thrombosis. We believe that the type of pharmacological intervention used is of less importance than the general experiences gained, which can be extrapolated to other studies and should stimulate a more general debate.

Clinical Trials as Topic↗

PubMed1996

A robust method for proportional hazards regression.

In this paper we give an informal introduction to a robust method for survival analysis which is based on a modification of the usual partial likelihood estimator (PLE). Large sample results lead us to expect reduced bias for this robust estimator compared with the PLE whenever there are even slight violations of the model. In this paper we investigate three types of violation: (a) varying dependency structure of survival time and covariates over the sample; (b) omission of influential covariates, and (c) errors in the covariates. The simulations presented support the above expectation. Analyses of data sets from cancer epidemiology and from a clinical trial in lung cancer illustrate that a better fit and additional insights may be gained using robust estimators.

Algorithms↗

PubMed1996

Intravesical versus intravesical plus intradermal bacillus Calmette-Guerin: a prospective randomized study in patients with recurrent superficial bladder tumors.

PURPOSE: Intravesical instillation of bacillus Calmette-Guerin (BCG) induces various immunological reactions and decreases the recurrence rate of superficial bladder tumors. To determine whether additional immune stimulation with concomitant intradermal BCG applications could further lower the recurrence rate, 154 patients with superficial bladder tumors at high risk for recurrence were randomized to receive either 6 intravesical instillations of 120 mg. Pasteur strain BCG alone or combined with intradermal application. MATERIALS AND METHODS: A total of 76 patients received intravesical and intradermal BCG, while 78 received intravesical BCG only. Median followup was 41 months (range 2 to 89) and 36 months (range 2 to 86), respectively. Both treatment groups were comparable regarding patient age and number of previous transurethral bladder tumor resections, as well as tumor recurrence rate, stage and grade before BCG therapy. RESULTS: A highly significant decrease in the monthly tumor recurrence rate was observed in both arms after BCG compared to the pretreatment recurrence rates (p < 0.0001). Recurrence rate decreased from 0.73 +/- 1.07 (standard deviation) to 0.06 +/- 0.13 in the combined treatment group and from 0.71 +/- 0.90 to 0.074 +/- 0.17 in the intravesical treatment only group. However, we were unable to find any difference between the 2 groups regarding interval to initial recurrence or recurrence rates after BCG treatment. Changes in the purified protein derivative skin test performed before and after BCG therapy were not useful to predict response to treatment because 44% of our patients already had a positive test before treatment. Also, interpretation of the skin test was difficult and not always reliable. In the multivariate analysis, however, fever was an important prognostic factor. Patients with increased body temperature greater than 37.5C had a significantly lower recurrence rate than those without fever (37.5C or less) after BCG instillation (p = 0.009). Moreover, fever after BCG instillation was observed significantly more frequently in patients with a positive purified protein derivative skin test before treatment (p = 0.021). CONCLUSIONS: The therapeutic benefit from intravesical BCG apparently was not substantially improved by simultaneous intradermal BCG vaccination. Fever following intravesical BCG instillation is an important prognostic factor regarding superficial bladder tumor recurrence. Fever occurs predominantly in patients who were previously sensitized to mycobacteria (by BCG vaccination or infection) as shown by a positive pretreatment purified protein derivative skin test. This finding suggests that previously sensitized patients respond significantly better to a single course of intravesical BCG.

Adjuvants, Immunologic↗

PubMed1996

Effects of exposure to 16.7 Hz magnetic fields on urinary 6-hydroxymelatonin sulfate excretion of Swiss railway workers.

The aim of our study was to examine the effects of 16.7 Hz electromagnetic-field exposure on pineal melatonin production in healthy humans. The study was based on comparing urinary 6-hydroxymelatonin sulfate (6-OHMS) levels of 108 male railway workers between leisure periods and days following the start of service on electrically powered engines (66 engineers) or working beneath transmission lines (42 railway employees such as train attendants and station managers; controls). A repeated measures design was used, i.e., each volunteer served as his own control. The exposure averaged 20 muTesla in the most exposed workers and around 1 muTesla in the least exposed. Apart from magnetic exposure the workers were subject to a shift work schedule with daily advances between 15 min and 1 hr. Melatonin was assessed by sampling urinary 6-OHMS both in the morning and the early evening. Evening 6-OHMS values appeared to be lowered by a factor of 0.81 (95%CI: 0.73-0.90) during work days compared to leisure days among engine drivers, but not in the controls. The lowering was not confined to certain types of shift work such as early, normal, or late shifts. During subsequent leisure periods evening values recovered significantly, mean ratio = 1.27 (95%CI: 1.03-1.56), i.e., the effects appeared to be reversible. In contrast, morning 6-OHMS samples of engineers and controls did not differ much between work and leisure days. There was, however, a tendency for a rebound of morning values in a leisure period following a work period both for engineers and controls. The observed pattern appears to be in line with predictions of the "phase response curve." No evidence for a dose-response relation was found. The results support the hypothesis that 16.7 Hz magnetic fields alter 6-OHMS excretion in humans exposed to magnetic fields. An alternative explanation that cannot be excluded in this study is that the difference between engineers and controls is due to differential exposure to day light at work.

Adult↗

PubMed1995

The relation of reported symptoms to social, individual, and behavioral indicators of ill-health: is the number of reported symptoms a unique general dimension of ill-health?

Counts of functional symptoms are an accepted measure of ill-health in general populations. However, their relation to other indicators of ill-health are still poorly understood. The aim of this study was to investigate such relations in order to reach a better understanding of the 'meaning' of the number of symptoms. The data analyzed was drawn from a telephone health survey conducted among a representative sample of 2111 Swiss adults as part of the Intercantonal Health Indicators Project in 1989. In a logistic regression analysis the Number of symptoms (a summery score of eleven severe function symptoms) was found to be strongly associated with eight social, behavioral, and psychological indicators of ill-health ('Unable to work', 'Frequently consulting a physician', 'Use of analgesics', 'Use of sedatives', 'Poor coping with ill-health', 'Social impairment', 'Poor health', and 'Poor psychological well-being'). To control for effects due to individual symptoms, they were included in the models by stepwise procedure. Although individual symptoms became predictive for all indicators (except for Poor coping with illness), the association between the Number of symptoms and the indicators (except for Social impairment) remained statistically significant. Despite methodological provisos our results seem to support an interpretation of the Number of symptoms as a distinct and general dimension of ill-health.

Adaptation, Psychological↗

PubMed1995

The prognostic significance of protein-energy malnutrition in geriatric patients.

Although it has been shown that protein-energy malnutrition is a predictor of adverse outcome in geriatric patients, it is unclear whether this is due to underlying disease or disability, or whether malnutrition is an independent outcome predictor. To clarify the predictive role of malnutrition, we analysed the 4.5-year mortality and living location follow-ups of 219 geriatric patients admitted to a geriatric assessment unit. Prevalence of anthropometric and serological malnutrition indicators were between 13.7% and 39.8% at hospital admission. In bivariate models, prealbumin, subnormal arm muscle area, and subnormal body weight were predictors of mortality and survival at home. On the other hand, albumin, transferrin, and triceps skin-fold thickness did not predict these outcomes. In multivariate models the hazard ratio (HR) of 4.5-year mortality remained significant with an HR of 1.8 (95% CI 1.3-2.6) for subnormal arm muscle area, and 1.6 (95% CI 1.0-2.6) for subnormal body weight. Prealbumin was the strongest serological outcome predictor (multivariate mortality HR 1.9, 95% CI, 1.3-2.8). In these models, subnormal cognitive function, impaired physical function, and creatinine clearance < 30 ml/min were also associated with increased mortality. Malnutrition did not predict hospital discharge location, but among patients discharged home, those with initial malnutrition had a decreased length of survival at home. Our findings indicate that certain protein-energy malnutrition indicators are independent risk factors predicting decreased length of overall survival and survival at home in geriatric patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Activities of Daily Living↗

PubMed1995

Decrease of incidence of toxic nodular goitre in a region of Switzerland after full correction of mild iodine deficiency.

In 1980 the iodide content of salt was increased in Switzerland from 7.5 to 15 mg/kg. This raised the mean urinary iodine excretion from 90 (indicating mild iodine deficiency) to 150 micrograms/g creatinine. We examined whether this public health measure was followed by a change of the incidence of hyperthyroidism in a defined catchment area of 109,000 persons. Except for a 27% rise in the first year of the new salt, the total incidence of hyperthyroidism declined steadily to reach 44% of the control level in 1988/89. This was due to a decrease mostly of toxic nodular goitre (minus 73%), less so of Graves' disease (minus 33%). We conclude that correction of mild iodine deficiency has beneficial effects on the incidence of hyperthyroidism, contrary to what is seen initially after correction of severe deficiency.

Female↗

PubMed1995

[Introduction to the statistical aspects of planning clinical oncologic phase III studies].

A phase III clinical trial is a comparative study in which one assesses the relative efficacy of a treatment or treatments. It generally has one of the following objectives: 1. To determine the effectiveness of a new treatment relative to the natural history of the disease, for example when comparing a new treatment to not treatment or to placebo in an adjuvant setting. 2. To determine if a new treatment is more effective than the best current standard therapy (at the risk of increasing the toxicity). 3. To determine if a new treatment is as effective as the best current standard therapy but is associated with less severe toxicity or a better quality of life (equivalence trial). Clinical trials must be properly designed in order to answer such questions with a high degree of certainty. The purpose of this paper is to present several concepts which must be taken into account during the process of designing a clinical trial.

Aged↗

PubMed1994

A mortality study of lung cancer among swiss professional drivers: accounting for the smoking related fraction by a multivariate approach.

The mortality due to lung cancer among 'chauffeurs', who have a presumably long-term exposure to diesel exhaust fumes, was analysed. As controls, men in industrial occupations of similar socio-economic status were selected. Cases were drawn from the Swiss mortality register for the years 1979-1983. Person-years were obtained using data from the 1980 census records. These two data files were combined by occupation, age class and socio-economic status. Age adjusted incidence rates were calculated applying Poisson regression. To control for tobacco related lung cancer mortality an indirect adjustment was undertaken. Using information about the smoking habits of the people in the occupations under study, smoking-attributable lung cancer mortality was accounted for by incorporating Axelson's technique into multivariate regression modeling. The mortality ratio for lung cancer for chauffeurs with respect to the controls was 2.27, which is significantly in excess of 1:95% CI (1.99, 2.58). Other tobacco related diagnoses such as bladder cancer, esophageal cancer and ischemic heart diseases showed excess risks as well. After accounting for smoking, a slight but significant increase in lung cancer mortality remained among chauffeurs (mortality ratio 1.48, 95% CI: 1.30, 1.68). In summary, the present results do support the hypothesis that diesel exhaust is a significant cause of lung cancer.

Adult↗

PubMed1994

Anesthetic depth defined using multiple noxious stimuli during isoflurane/oxygen anesthesia. I. Motor reactions.

BACKGROUND: Potency of inhaled anesthetics usually is defined by determining the minimal alveolar concentration (MAC) that prevents movement in 50% of patients in response to skin incision. Skin incision, however, is usually only a single event and, thus, determination of potency cannot be repeated in one patient. Traditional MACskin incision cannot be used to predict response to other noxious stimuli. The aim of this study was to investigate the effects of other noxious stimulation patterns and then compare these to MACskin incision measuring the end-tidal isoflurane concentrations with the corresponding arterial concentrations. METHODS: In 26 patients, the end-tidal and corresponding arterial isoflurane concentrations needed to suppress eye opening to verbal command and motor response after trapezius squeeze, 50 Hz electric tetanic stimulation, laryngoscopy, skin incision, and tracheal intubation in 50% of all patients were determined. RESULTS: The end-tidal (equivalent arterial) isoflurane concentrations (mean +/- SE, adjusted to sea level) expressed in vol% (to allow comparison) increased in the following order (mean +/- SE): vocal command 0.37 +/- 0.09 (0.36 +/- 0.09); trapezius squeeze 0.84 +/- 0.07 (0.65 +/- 0.07); laryngoscopy 1.00 +/- 0.12 (0.78 +/- 0.09); tetanic stimulation 1.03 +/- 0.09 (0.80 +/- 0.06); skin incision 1.16 +/- 0.10 (0.97 +/- 0.17); and intubation 1.76 +/- 0.13 (1.32 +/- 0.11). CONCLUSIONS: Different stimuli require different isoflurane concentrations to suppress motor responses. Tetanic stimulation and, to some extent, trapezius squeeze are reproducible and noninvasive stimulation patterns that can be used as an alternative to skin incision when evaluating potency of an anesthetic agent. In contrast to skin incision, they can be repeated.

Adult↗

PubMed1994

Incidence and duration of breast-feeding of ill newborns.

The many biological advantages of breast milk call for promoting breast-feeding. The extent to which separation of ill newborns from their mothers negatively influences breast-feeding is not known. By means of a written inquiry, we investigated the prevalence of exclusive, partial, and no breast-feeding of 536 newborns hospitalized at a tertiary care neonatal center with no inborn patients. Three hundred twenty-seven questionnaires were completed correctly. Fifty percent of the mothers eventually succeeded in exclusive breast-feeding, 25% in partial breast-feeding, and 25% never breast-fed. The frequency of breast-feeding was similar to the Swiss average for the first 4 months of life in healthy newborns and declined more rapidly thereafter. Univariate and multivariate statistical analyses have shown that the following conditions influence breast-feeding negatively: gestational age < or = 33 weeks, maternal age > 25 years, and lower professional status of the father. Additionally, multivariate analysis revealed a promoting effect of previous breast-feeding. Exclusive breast-feeding has eventually been possible in half of the newborns who had initially been separated from their mothers due to illness. Knowledge of the conditions influencing breast-feeding in such populations should help to promote breast-feeding more specifically in tertiary neonatal centers.

Adult↗