Hans-Peter Zeitler

Virtual patients for assessing medical students–important aspects when considering the introduction of a new assessment format

Background: A case-based online assessment tool has been accomplished at the University of Ulm by simulating consultations with virtual patients in General Practice setting. After a successful pilot study, more data on validity were needed as one important step when considering introducing this assessment format to replace the regular written course exam. Methods: Five distinct sources of validity evidence are addressed: content, response process, internal structure, relationship to other variables and consequences. An examination simulation was conducted including all students (147) of the General Practice course, scores of three virtual patient cases compared with the written course exam and data gathered regarding usability, acceptance, content and structural characteristics, and consequences. Results: All five aspects were supported by collected data. Correlation to the written exam was moderate with r = 0.36, correlation between the cases higher with r = 0.50–0.56. Conclusion: Although a direct comparison of written course exams and dealing with virtual patients is difficult in many aspects and the study setting as an exam simulation caused confounders, this new assessment format is supported by many aspects of validity evidence. Solving virtual clinical scenarios addresses other abilities, skills and knowledge than traditional written exams and since “assessment drives learning” it could have positive implications on teaching and learning alike.

A Comparison of Different Strategies to Collect Standard Gamble Utilities

Objective. The authors performed a methodological comparison of the usual standard gamble with methods that could also be used in mailed questionnaires.Methods.Ninety-two diabetic patients valued diabetes-related health states twice. In face-to-face interviews, the authors used an iterative standard gamble (ISG) in which the probabilities were varied in a ping-pong manner and a self-completion method (SC) with top-down titration as search procedure (SC-TD) in 2 independent subsamples of 46 patients. Three months later, all patients received a mailed questionnaire in which the authors used the self-completion method with bottom-up (SCBU) and SC-TD as search procedures.Results.ISG and SCTD showed feasibility and consistency in the interviews. The ISG resulted in significantly higher utilities than the SC-TD. Two thirds of the mailed questionnaires provided useful results indicating some problems of feasibility. Utilities measured by SC-BU and SC-TD did not differ significantly showing procedural invariance. Further, patients indicated ambivalence when given the choice not to definitely state their preferences.Conclusions.The results show that different strategies to collect standard gamble utilities can yield different results. Compared with the usually applied ISG, the SC method is feasible in interviews and provides a consistent alternative that is less costly when used in mailed questionnaires, although its practicability has to be improved in this later setting.

How important is a package insert for drug therapy in ambulatory care

German regulations demand an extensive package insert for drugs. However, to what extent the information given is used and what consequences this use actually has remain unclear. The aim of this study was to describe different patterns of patient package insert (PPI) use, to estimate the proportion of each of these patterns, and to evaluate the impact of the information on patients’ reported medication compliance. In spring 2005, 45 randomly chosen customers from five urban pharmacies were questioned about their behaviour regarding PPI. Interviews were based on a structured interview guideline, and were electronically recorded, transcribed and coded in a consensus process. Less than one-half of the patients interviewed were able to repeat specific PPI content. A minority of patients had probably read the PPI, but could not remember any details. Patients had read the PPI only superficially, did not understand its meaning, had read it long time ago, or gave a socially requested answer. Reading the PPI has fewer consequences in terms of an arbitrary change of the prescribed drug concept than has been previously assumed. Recommendations of physicians and pharmacists were more helpful than information contained in a PPI. Due to a sense of responsibility, the PPI is read more thoroughly if third persons are affected. PPIs are read only selectively, a finding that should be considered when writing them.

Epidemiology and determinants of nocturnal calf cramps

Objectives: Nocturnal calf cramps are a health impairment frequently encountered in primary healthcare. Nevertheless, not much is known about prevalence, determinants, comorbidity and management of the condition.Methods: Survey by means of a postal, self-administered questionnaire sent to all adults who attended a single-handed general practitioner in a six-month period.Results: A total of 1675 questionnaires were sent out, the response rate was 71.4%. In the study population there was a four-week prevalence of 24.1% and an estimated incidence of 40 new cases per 1000 per year. Nocturnal calf cramps were more prevalent in older persons, in persons with a higher body mass index (BMI), in women, in patients with varicosis, diabetes, peripheral vascular disease, and in non-smokers. There was at least one self-reported incident of nocturnal calf cramps with at least level 2 pain on a 10-point pain measurement scale within the past four weeks. In a multiple logistic regression analysis, age, varicosis, diabete...

Unexpected Yes- and No-Answering Behaviour in the Discrete Choice Approach to Elicit Willingness to Pay: A Methodological Comparison with Payment Cards

When measuring willingness to pay (WTP) by contingent valuation surveys, several elicitation methods can be applied. The most common methods are the discrete choice (DC) approach and payment cards.The purpose of this study was to analyse the convergent validity of both approaches in order to investigate different kinds of answering behaviour in these approaches. Unexpected deviations of the answers in the DC approach from the answers provided on the payment cards were analysed, i.e. unexpected yes- (no-)answering was given when respondents stated to the DC question that they are (not) willing to pay a monetary amount while they stated the opposite on the payment cards. Furthermore, we analysed the feasibility of these two elicitation methods. Each of a group of 92 diabetic patients was asked to state their WTP for reductions of the risk of several diabetic complications by both elicitation methods in two surveys. Both elicitation methods were feasible. Compared with the WTP stated on the payment cards, we found unexpected yes- as well as no-answering behaviour in the DC approach which partly balanced each other. At low bids, there was a tendency that unexpected no- outweighed unexpected yes-answering behaviour. At high bids, unexpected yes- outweighed unexpected no-answering behaviour. Overall, unexpected yes-answering behaviour was predominating. Several explanations for these phenomena remain to be investigated.

Development and validation of a simple, two-step algorithm to identify streptococcal infection in adults with sore throat

Objectives: Development and validation of a clinical algorithm to identify infection with group A β-haemolytic streptococci in patients with sore throat, using a clinical score and measurement of C-reactive protein for selected patients. Design: Two phased study. Phase 1: Development of a clinical score from structured clinical records by logistic regression analysis and Bayesian analysis. Phase 2: Prospective validation of the score developed in phase 1. Setting: One GP practice in Germany (two GPs) for development of the score, five German GP practices (six GPs) for validation of the score. Subjects: Consecutive patients aged 16 or older presenting with newly developed sore throat, n=116 (phase 1), n=265 (phase 2). Main outcome measures: Infection by group A β-haemolytic streptococci diagnosed by means of throat swab cultures on selective Columbia agar. Results: Development of a two-step algorithm consisting of a clinical score of four parameters (throat mucosa, uvula, soft palate, tonsils) and near-patient quantitative measurement of C-reactive protein for selected patients with an ambiguous score. In the validation phase the algorithm has a diagnostic accuracy of 89.4%, a sensitivity of 0.74 (95% confidence interval (CI)=0.53-0.89), a specificity of 0.95 (95% CI=0.88-0.99), positive predictive value of 0.86 (95% CI=0.65-0.97) and a negative predictive value of 0.91 (95% CI=0.81-0.96). To achieve the accuracy, a measurement of C-reactive protein is necessary in 30% of patients with sore throat. Conclusions: The algorithm, consisting of a clinical score and selective measurement of C-reactive protein, achieves a diagnostic accuracy of almost 90% in diagnosing infection by group A streptococci in adults with sore throat.