Rasch analysis of professional behavior in medical education.

The use of students' "consumer feedback" to assess faculty behavior and improve the process of medical education is a significant challenge. We used quantitative Rasch measurement to analyze pre-categorized student comments listed by 385 graduating medical students. We found that students differed little with respect to the number of comments they provided and that their comments indeed form a probabilistic Rasch hierarchy. However, different hierarchies were found across medical departments and faculty. An analysis of these interactions provides valuable, detailed, and quantitative information that can augment qualitative research approaches. In addition, we suggest how the Rasch scaling of student comments can assist researchers in the design and implementation of new faculty evaluation instruments. Finally, the interactions between student and department identified a subset of behaviors that appear to guide and possibly elicit students' comments.

Business quality control in issuing life insurance.

Fraud investigation and fraud control are entirely different processes. Similarly the auditing of a life insurance company and the issuing of life insurance policies and business quality control are not the same. Business quality control and fraud control have much in common. In this article, these similarities are explored and a case is made that companies issuing life insurance policies should consider the business quality control approach rather than the more traditional investigatory methods.

Effect of coating with lung lining fluid on the ability of fibres to produce a respiratory burst in rat alveolar macrophages.

The aim of the study was to develop a simple short-term in vitro assay which would allow us to predict the pathogenicity of fibres based on data already available from in vivo studies. Fibres were used naked (uncoated) or coated with rat IgG, or rat or sheep surfactant. The fibres were used to stimulate superoxide anion release by rat alveolar macrophages. Binding of fibres to rat alveolar macrophages was assessed by optical microscopy. Fibres used in the naked state produced little or no stimulation of superoxide anion from rat alveolar macrophages. When fibres were coated with rat IgG there was a significant increase in superoxide release for all fibre types with the exception of RCF4 and Code 100/475. When fibres were coated with rat or sheep surfactant, there was suppression of the respiratory burst for all fibre types. The observed suppression was not due to a scavenging effect by the surfactant itself, because xanthine/xanthine oxidase generated superoxide was unaffected by surfactant. The suppressive effect was shown to act directly on the macrophages. Comparing naked and coated fibres for their ability to bind to macrophages, it was shown that in general more coated fibres were bound and that increased binding was associated with suppressed superoxide release for both types of surfactant-coated fibres. It was concluded that the nature of the fibre coating is the main factor influencing the interaction between fibres and macrophages. The type of binding through different receptors may either stimulate or switch off the respiratory burst. The assay used here does not, however, allow any predictions to be made regarding the pathogenicity of fibres.

Optimized and corrected peak power output during friction-braked cycle ergometry.

Assessments of maximal intensity exercise which determine peak power output on friction-baked cycle ergometers have fallen into two categories: correction procedures which account for changes in momentum of the ergometer's flywheel and optimization procedures which attempt to satisfy muscle force-velocity relationships. The aim of this study was to compare performance in each procedure and so investigate assumptions which underpin the tests. Nineteen males aged 20.9 +/- 0.4 years and 18 females aged 22.2 +/- 0.7 years (mean +/- S.E.M.), who were fully accustomed to the procedures, participated in a single experimental protocol. After a 5 min warm-up, the subjects performed four bouts of all-out exercise on a Monark 814E cycle ergometer against randomly assigned loads. The loads were selected to produce peak pedalling rates in the range 100-200 rev min-1 and each bout lasted 10 s. From the inverse linear relationship between applied load and peak pedalling rate, optimized peak power output (PPopt) and the accompanying pedalling rate (RPMopt) were calculated. One of the bouts used a loading equivalent to 7.5% of body weight and for this bout corrected peak power output (PPcorr) and its corresponding pedalling rate (RPMcorr) were calculated. The PPopt was less than PPcorr in the males (915 +/- 35 vs 1005 +/- 32 W) and females (673 +/- 33 vs 777 +/- 39 W) (both P < 0.001). Similarly, RPMopt was less than RPMcorr (111 +/- 1 vs 128 +/- 2 rev min-1 and 101 +/- 1 vs 111 +/- 2 rev min-1 in the males and females, respectively; P < 0.001). The results demonstrate that optimization and correction procedures produce different values of performance. These differences are probably attributable to the mechanical principles which underpin the tests.

The selective approach to successful stomal management at home.

Practical aspects of caring for a patient's tracheal stoma at home are reviewed, based on our experience with 1,000 head and neck cancer and/or laryngotracheal stenosis patients treated at a large, multidisciplinary medical center. Successful management depends on understanding the various types of stomas and relating basic principles of hygiene to the fundamental concepts of wound healing and inflammation. There is no standard formula. Each case requires individual attention and planning.