The Questionnaire D-RECT German: Adaptation and testtheoretical properties of an instrument for evaluation of the learning climate in medical specialist training

AIM

Boor et al developed and validated the questionnaire D-RECT (Dutch Residency Educational Climate Test ) to measure the clinical learning environment within the medical specialist training. In this study, a German version of this questionnaire (D-RECT German) is analyzed regarding testtheoretical properties.

PROBLEM

Are the results of Boor et al replicable as a proof for validity of the questionnaire D-RECT?

MATERIAL & METHODS

The study was performed as online survey using the questionnaire D-RECT German (50 items in 11 subscales). To determine item characteristics and internal consistency (Cronbach's α), item- and reliability analyses were performed. Furthermore, a confirmatory factor analysis was performed using a model for maximum-likelihood estimation to evaluate validity.

RESULTS

This replication study on the psychometric properties of the D-RECT with 255 residents at 17 German hospitals revealed heterogeneous discriminatory power for all items and an internal consistency of Cronbach's α between 0.57 and 0.85. Within the confirmatory factor analysis, 6 items showed standardized regression coeffizients <0.5, two of them in the subscale "Attendings role". Furthermore, strong interdependencies (>0.7) were found between the subscales "Supervision", "Coaching" and "Attendings role".

CONCLUSION

The present replication study with the D-RECT German showed structural differences with respect to factorial validity underpinning the need of further validation studies.

[Nationwide evaluation of German university teaching methods in neurology]

BACKGROUND

Germany is confronted with a lack of medical doctors and an increasing need for neurologists in particular. In order to recruit future doctors in neurology it is essential to attract young students when still at university.

OBJECTIVES

This article presents the first German national survey of medical students' acceptance of teaching methods in neurology. The participants evaluated teaching methods and examination formats and were asked about their preferences.

MATERIAL AND METHODS

The survey was based on a questionnaire distributed to 22 German medical schools and 1245 participating students.

RESULTS

Interactive teaching methods, especially courses in practical examinations, clinical internships and bedside teaching were highly rated among the students. In contrast, multiple choice tests, as one of the most widespread examination methods, were poorly rated compared to practical and oral examinations. For most of the students it was not decisive, in which semester teaching of neurology took place, while the majority asked for additional and more intensive neurological education.

CONCLUSION

The data give an overview of teaching of neurology in Germany and students' assessment of various approaches. The results should be utilized towards reorientation of future curricula that should aim at innovative and even more practically oriented teaching.

Using an audience response system to improve learning success in practical skills training courses in dental studies - a randomised, controlled cross-over study

INTRODUCTION

The aim of this study was to examine whether the use of an audience response system (ARS) in a high-quality study design, in a course in pre-clinical dentistry leads to an improvement in cognitive and psycho-motor performance.

MATERIALS AND METHODS

As part of the Phantom Course I, a randomised, controlled study in cross-over design with 63 students was conducted over 4 weeks. The intervention was carried out by means of an ARS (TurningPoint(®) ), while a verbal question-and-answer session was conducted within the control group. Differences in learning success were determined via a formative multiple-choice (MC) test (cognitive) and a summative practical test (psycho-motor).

RESULTS

Both groups achieved significantly better results in the MC tests with the use of the intervention, when compared with the control group (group A 11.6 vs. 9.5 and group B 13.7 vs. 12.1, maximum 16 points). A further analysis of the results showed that the overall effect was induced primarily by a marked improvement in below-average students. The practical tests showed no clear effect. Despite the careful selection and set-up of the conditions for the study in the regular course of the semester, a cohort effect emerged. This was due to varying degrees of performance between the two groups, because no adequate performance parameters were available, which could have been taken into account for the stratified randomisation.

CONCLUSIONS

The results indicate that the use of the ARS leads to better results in cognitive performance, especially where independent learning is required and should be encouraged. Weaker students in particular seem to benefit.

[University teaching in clinical neurology: present situation and future requirements]

BACKGROUND

In German Hospitals there is a lack of medical personnel and doctors in particular. Clinical specialities and hospitals are in competition for students and young doctors and these, in turn, have clear cut demands regarding working conditions and professional training. To date there is considerable heterogeneity regarding clinical teaching in neurology between different German universities. There are no data available for systematic comparison.

MATERIAL AND METHODS

This article presents for the first time data from a survey on academic teaching in neurology in German university hospitals.

RESULTS AND CONCLUSION

The data show that many faculties are dedicated to modern and practical teaching methods and have employed state of the art examinations and progress tests. Further and ongoing efforts will be needed in order to inspire medical students and young doctors for this interesting clinical speciality. Connecting individual formats and networking between universities, teaching hospitals, including novel developments together with the young neurologists will help to structure our efforts and increase sustained attractiveness of clinical neurology for the following generations of young doctors.

Psychomotor performance and subjective symptoms at low level toluene exposure

OBJECTIVES

Possible effects of long term occupational exposure to toluene below the level of 100 ppm on psychomotor performance and subjective symptoms were investigated in a cross sectional approach.

METHODS

From German rotogravure printing plants 278 male workers, mean age 39.8 years, mean duration of employment 14.9 years, were examined. A mean lifetime weighted average exposure (LWAE) of 45.1 ppm toluene in ambient air was found for 154 exposed workers (rotogravure printing area), with a mean current exposure of 24.7 ppm. The corresponding data for a second group of 124 workers with very low exposure (endprocessing area) had LWAE of 9.3 ppm and a current exposure of 3.3 ppm toluene. Psychomotor performance (steadiness, line tracing, aiming, tapping, and peg board) and subjective symptoms were examined.

RESULTS

No significant differences between the two exposure groups were found by analysis of variance (ANOVA). By stepwise linear regression analyses there were weak associations of LWAE with one performance variable and two symptoms scales, but the results were not significant after correction for the alpha error. Psychomotor performance was mostly affected by age (maximum explained variance up to 13%), and handedness (up to 9%), whereas subjective symptoms are mostly affected by anxiety (up to 38%).

CONCLUSIONS

The weak associations between long term exposure to toluene should be used to indicate further longitudinal investigations. The results of this cross sectional study show no obvious dose response relation for psychomotor functions and subjective symptoms among workers exposed to toluene at a current exposure level of 1-88 ppm.

Individual toluene exposure in rotary printing: increasing accuracy of estimation by linear models based on protocols of daily activity and other measures

Industrial exposure varies distinctly both between persons and for each person over time. It is often not possible to measure individual exposure repeatedly due to high costs. Therefore, a method for assessment of exposure is needed that accounts for inter- and intraindividual variability. We consider a strategy suggested by Preller et al. (1995, Scandinavian Journal of Work, Environment, and Health 21, 504-512), the idea of which is to predict exposure on several days via a linear model using additional variables as regressors. Those additional variables are easier to obtain than exposure measurements and are assumed to influence exposure. The paper gives a theoretical proof of the use of this method. An example is given using toluene exposure data from a study in a rotogravure printing plant.

Switching attention--additional aspects for the analysis

Problems related to attentional functions have often been reported within the neurotoxicology of long-term exposure to solvents, but knowledge about neuroanatomical sites involved in this degenerative process is still rare. However, some studies have emphasized the frontal cortex as a region of structural or functional changes in long-term exposed patients or accidental intoxications. Neurobehavioral tests using active switching tasks are widely used to detect frontal lobe dysfunction. Test batteries used in neurotoxicology provide such tasks but standard test interpretations often neglect these aspects. Rotogravure printing workers exclusively exposed to toluene were investigated in a longitudinal study with cross-sectional design. Data from two examination periods are presented. In the first sample 333 male workers were investigated. In the second examination period 278 workers could be retested. The workers differed with respect to level and duration of lifetime exposure to toluene. All subjects completed a neurobehavioral test battery including the task switching attention (EURONES). Different parameters were computed for consecutive trials with constant vs. shifted tasks and repetitions vs. changes of the response direction. In general the expected interaction between the two sequence factors could not be observed. In both examination periods the alternative strategy revealed no marked differences between task/response shifts. Considering the result of previous studies on task/response shifts, the results were highly unexpected. One explanation might be the strong deviations from equality for the relative frequencies of the four sequence conditions, resulting in biased expectancies. These may have superimposed on the basic effects of task shifts. However, in both examination periods weak effects of task shift could be revealed in the subgroup of the long-term exposed workers. In further studies it is necessary to balance conditions more carefully in order to exploit the sensitivity that the measurement of shift costs promises to provide. The exposure-related results of this study support this aspect.

Subjective symptoms due to solvent mixtures, dioxin, and toluene: impact of exposure versus personality factors

In this study, we analyse the impact of personality factors on the frequency of self-reported symptoms for workers under different exposure conditions. Reported symptoms may depend on the level and type of exposure, as well as on personality factors such as trait anxiety of the worker or his general sensitivity with regard to the environment. The employed data stems from three studies: The first study contains information of 60 workers who suspected to be exposed to polychlorined dibenzodioxins and dibenzofuranes (Lifetime Weighted Average Exposure, LWAE, as an index for contact with the substances). The second study concerns 40 workers who are exposed to different concentrations of solvent mixtures in paint manufacturing (LWAE of total hydrocarbons about 10 ppm). The third study includes repeated measurements of two subgroups of workers from rotogravure printing plants who are exposed to different concentrations of toluene: a "high" exposure group (n = 129, LWAE about 46 ppm, current exposure 25 ppm) and a "low" exposure group (n = 96, LWAE for toluene about 9 ppm, current exposure 3 ppm). Trait anxiety, environmental sensitivity, and self-reported symptoms are measured by validated questionnaires and age as well as verbal intelligence are controlled. To determine the effect of the individual characteristics and the different exposures on self-reported symptoms, frequency analyses and variance analyses are conducted and linear models are fitted. For all analyses, trait anxiety explains the highest share of the variance. If there is no effect of the exposure on the reported symptoms (dioxin and low-level toluene study), trait anxiety seems to have a larger explanatory power in comparison with those studies where the exposure has an effect on the reported symptoms (solvent-mixture and high-level toluene study). Neurotoxicological risk analysis has to account for the detected dependence of self-reported symptoms on personality traits: assessments for elevated symptoms should not only be linked to the intensity of exposure but also related to benchmarks derived from the normal variability of personality factors.

Neurobehavioral study on the interactive effects of age and solvent exposure

Initial research revealed interaction effects on health measures between exposure to neurotoxicants and age. Symptom reports of workers were conspicuously increased if high-concentration occupational exposure (e.g. to organic solvents, lead) was combined with age above 54 years. The symptom increase in elderly workers was interpreted as a possible indicator of a biological vulnerable phase or delayed response of former high exposure. A second study of the hypothesized age-exposure interaction was performed with a group of workers who had homogenous exposure to a single organic solvent using a neurobehavioral performance evaluation (the EURO-NES). Workers in the rotogravure printing industry who were exposed to toluene were examined two times with an interval of one year (n =333/278). The sample was stratified by workers with significantly different toluene exposure, printers and end-processing operators, and four age classes (< 31, 31-40, 41-50, > 50). The mean lifetime weighted average exposure (LWAE) varied depending on age classes and years of employment with exposure between 7 and 17 ppm in the operators and between 35 to 62 ppm toluene in the printers. Multivariate analyses revealed a significant performance decrease with age (simple reaction time, symbol digit, switching attention, digit span). Again an interaction between age and exposure was found depending on diverging psychometric performance trends with older age. However, contrary to the hypothesis the group with higher exposures (printers) and older age revealed better performance and less symptoms than the group with lower exposure (end-processing operators). The paradoxical results are explained by differences in the intellectual capability in the oldest strata and a possible reversibility of neurobehavioral effects of former high toluene exposure under the condition of later low exposure. There are no hints of adverse delayed effects of former toluene exposure in a possible vulnerable phase in age over 50 years. The different interaction findings of the initial and present study seem to depend mainly on exposure differences in quality and quantity.

Association of biochemical and subjective indicators of drinking habits with performance on different neurobehavioral tasks

The present paper outlines the association of biochemical and subjective indicators of alcohol consumption. Due to its relevance as a potential confounding variable in occupational neurotoxicology, both sources of information about drinking habits were related to neurobehavioral test performance. A sample of 308 rotogravure printers and control subjects from a cross-sectional longitudinal study in various German printing plants was studied. Duration of employment was 4 months to 44 years (mean = 14.9, sd = 9.67). Mean age was 38.4 years (range 21 - 60). From venous blood samples three parameters considered to be sensitive for increased consumption of alcohol were used. They were carbohydrate-deficient transferrin (CDT), gamma glutamyl transferase (GGT), and mean cell volume (MCV). During the medical interview subjects with any chronic liver disease were identified and excluded from data analysis. Additionally, information about weekly consumption of alcohol was assessed and transformed to grams per day (g/d) values. Neurobehavioral testing included simple reaction time (SPES version), switching attention, symbol digit substitution, and digit span (EURONEST version). Additionally, a questionnaire of neurotoxic complaints was administrated. Other covariates, i.e. verbal ability, history of solvent exposure, and age were controlled. GGT and CDT were elevated in 10.5% and 6.6% of the population. 3.5% of the subjects reported daily consumption higher than 60 gram. There were positive correlations of CDT and GGT with the subjective indicator of drinking habits. The magnitude of these relationships were low, but the associations were significant. MCV was not correlated with subjective reports of drinking habits, but it showed convergent correlations with CDT and GGT. Comparison of these two parameters with performance on neurobehavioral tasks yielded only one negative association, i.e. between the memory-loaded tasks factor and GGT. CDT and subjective estimation of alcohol consumption were not related to any cognitive function tested in this study. Especially, the digits-backward task was negatively correlated with increased GGT.

In search of dose-response relationships of solvent mixtures to neurobehavioural effects in paint manufacturing and painters

Four exposure indices for the evaluation of mixtures of solvents are outlined. The hygienic effect is a relative measure depending on the limit values of the single compounds of the mixture. The cumulative lifetime exposure (CE) and the lifetime-weighted average exposure (LWAE) are approaches based on measurements of total hydrocarbons at workplaces in different time periods. Estimations of litres of solvents used per day years (l/d years) are necessary if air monitoring is not available. Five studies on neurobehavioural effects due to solvent mixtures in paint manufacturing are compared as example for dose-response relations. The best prediction of neurobehavioural dose-response relations seems to be possible using CE and LWAE for total hydrocarbon as the exposure index. Moreover, four studies on neurobehavioural effects due to solvent mixtures in paints and glues are compared. These studies indicate that the index l/d years is helpful in predicting neurobehavioural deficits. Of numerous neurobehavioural tests, the test symbol digit substitution shows the most significant dose-response relations in the studies. For symptom questionnaires these relations appear only occasionally. In principle, associations between doses of solvent mixtures in paints and neurobehavioural effects are reproducible to a limited extent.