Biomedical subjects

Hans-Peter Zeitler

Publications and source records attributed to Hans-Peter Zeitler.

4 recordsLinked to original sources

PubMed2006

[A complex process: decision-making in general practice: 117 structured case analyses].

BACKGROUND: A variety of factors seem to play a role in decision-making in general practice. To describe the complexity of this process a vague symptom with a broad spectrum of possible causes and outcomes was chosen: dizziness. Aim of this study was to provide a conceptual framework to describe and assess the complex reasoning process of general practitioners. METHODS: 22 GPs were interviewed about the patients seeking help for dizziness. The semi-structured focussed interviews were qualitatively analysed by consensus method. RESULTS: By 117 structured case analyses factors with influence on the decision-making process were identified and assigned to 7 different domains. Concepts described in literature were found as well as less well-known or even not accepted motives. CONCLUSIONS: Influenced by a variety of parameters, the decision-making process in general practice is complex. It is necessary to be aware of them to be able to deal with them.

Aged, 80 and over↗

PubMed2004

A utility-theoretic approach to the aggregation of willingness to pay measured in decomposed scenarios: development and empirical test.

For cost-benefit analysis, health technologies with multiple effects should be valued in a single scenario by a holistic willingness-to-pay (WTP) measure. Recent studies instead used decomposed scenarios in which respondents report their WTP for each individual effect. Evidence can be found that the sum of such decomposed WTPs overestimates the holistic WTP, i.e. the holistic WTP is sub-additive. This sum of decomposed WTPs can lead to wrong conclusions on the efficiency of health technologies. This is also relevant in decision making about new technologies that are valued separately in different surveys. To date, no utility-theoretical and empirically validated aggregation function for decomposed WTPs exists. Within an expected utility model, this paper identifies as a reason for sub-additivity--beside risk aversion with respect to wealth--a negative influence of better health on the marginal utility of wealth, i.e. marginal utility of wealth is smaller in better health states. Assuming mutual utility independence of health and wealth, a theoretically founded aggregation function covering these two impacts is derived. In a contingent valuation study, 92 patients with diabetes were asked to state their WTP for reductions of the risk of several diabetic complications in decomposed as well as in holistic scenarios. The patients had preferences with a significant negative influence of health on the marginal utility of wealth. Sub-additivity occurred and theoretically founded aggregation could considerably lower the degree of overestimation. These results suggest that the theoretically founded aggregation function might reduce problems of sub-additivity that can be economically relevant. Further empirical testing of the approach is indicated.

Aged↗

PubMed2003

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.

Aged↗

PubMedDate not supplied

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.

Aged↗