Optimal planning of phase II/III programs for clinical trials with multiple endpoints

Owing to increased costs and competition pressure, drug development becomes more and more challenging. Therefore, there is a strong need for improving efficiency of clinical research by developing and applying methods for quantitative decision making. In this context, the integrated planning for phase II/III programs plays an important role as numerous quantities can be varied that are crucial for cost, benefit, and program success. Recently, a utility‐based framework has been proposed for an optimal planning of phase II/III programs that puts the choice of decision boundaries and phase II sample sizes on a quantitative basis. However, this method is restricted to studies with a single time‐to‐event endpoint. We generalize this procedure to the setting of clinical trials with multiple endpoints and (asymptotically) normally distributed test statistics. Optimal phase II sample sizes and go/no‐go decision rules are provided for both the “all‐or‐none” and “at‐least‐one” win criteria. Application of the proposed method is illustrated by drug development programs in the fields of Alzheimer disease and oncology.     

Standardisierte Qualitätsinformationen und ihr Einfluss auf die Wahl von Leistungsanbietern – Ergebnisse einer empirischen Studie am Beispiel der Qualitätsberichte von Krankenhäusern

This study analyses the impact of standardized quality information of complex services on decisions, exemplified for Germany’s hospital quality reports. The presumed impact of quality information on decisions is based on theoretical considerations and hypotheses are developed accordingly. Though results of two experiments show that simplified quality indicators used in the quality reports for hospitals basically lead to consistent decisions, results also show that the impact of standardized quality information on decisions is not stable. It is disturbed and superimposed by the effects of additionally presented quality information. Implications for competition on hospital markets and for the effectiveness of standardized quality information as they are used in the hospitals’ quality reports are discussed as well as general conclusions about standardized information of complex services are drawn.     

Wertschöpfungs- und Werteinforderungsnormen im Rahmen der „Plural Form Governance“: Ein empirischer Test in Key-Account- und Nicht-Key-Account-Dyaden

In order to secure against uncertainty in vertical business relationships, actors dispose of different mechanisms. This article focuses on the influence of contracts, specific investments, value-creating norms, value-claiming norms, and trust on customer satisfaction and commitment. An empirical study lead to the result that governance mechanisms have high explanatory power for the outcome variables. Value-creating norms and trust play a key role. In addition, the article differentiates between key account and non key account relationships. It shows that only value-creating norms contribute to the explanation of both outcome variables across both types of relationships.     

Coaching von etablierten Professor/innen

Coaching for professors is increasingly gaining in importance at German universities. Especially the more established professors are challenging to reach. This article identifies and analyzes the established professors as a target group for business coaching in academia. Unique requirements concerning their management tasks and professional role are presented. Basic reasons for coaching of established professors are demonstrated in three characteristic case studies from practical experience.     

Kunst und Preise

How are prices established in the market for contemporary art? Buyers in this market are confronted with fundamental uncertainty since “quality” is only difficult to determine and the development of prices is non-predictable. Since the emergence of a market for contemporary art presupposes at least the possibility for intentional rational decision-making, this uncertainty must be reduced. We argue that the value of a piece of art or an artist is established in an intersubjective process of granting reputation by experts and institutions in the field of art. This is achieved primarily through the institutions of the art market and the training of artists, i.e. through galleries, curators, critics, art dealers, journalists, collectors, and art schools. They participate jointly in the making of artistic reputation of the artist’s work that provides, in turn, the basis for the determination of its economic value. For testing this hypothesis we assembled and analyzed two datasets with data on the biographies of artists and prices for their works.     

Mortality in the two Germanies in 1986 and trends 1976–1986

By using the new analysis programme LIFETIME the mortality data of the Federal Republic of Germany and the GDR are compared by age, sex and cause of death. The data submitted to the WHO were used for this purpose. Within the period from 1976 to 1986 life expectancy has risen in the Federal Republic of Germany, whereas in the GDR it increased to a minor extent only, so that the gap between the two parts of Germany has clearly enlarged. This enlarged gap in life expectancy largely depends on a higher mortality in the GDR due to diseases of the circular system and the respiratory organs, external influences and ‘other’ causes of death. The last-mentioned two groups also ‘contain’ the normally separatedly reported causes of death ‘cirrhosis of the liver’, ‘suicide’, ‘accidents’, and some diseases of the digestive system. These causes of death probably have gained a certain weight — like in other Eastern European countries — so that their evidence has been undesirable due to political reasons. In 1976 the GDR still reported these causes of death separately.     

Numerical estimation of a probability measure

An iterative solution to the problem of maximizing a concave functional ø defined on the set of all probability measures on a topological space is considered. Convergence of this procedure and a rapidly converging algorithm are studied. Computational aspects of this algorithm along with the ones developed earlier by Wynn, Fedorov, Atwood, Wu and others are provided. Examples discussed are taken from the area of mixture likehoods and optimal experimental design.     

The economy of risk and respect: accounts by Puerto Rican sex workers of HIV risk taking

Three-hundred-eleven female drug-using sex workers in urban Puerto Rico were asked to describe their last negotiation with a client. They described efforts to protect themselves from many hazards of sex work, including violence, illness, and drug withdrawal. They also described efforts to minimize the stigma and marginalization of sex work by cultivating relationships with clients, distinguishing between types of clients, and prioritizing their role as mothers. Sex workers adopted alternating gender roles to leverage autonomy and respect from clients. Their narratives suggest that sex workers negotiate a world in which HIV is relative to other risks, and in which sexual practices which are incomprehensible from an HIV-prevention perspective are actually rooted in a local cultural logic. Future HIV prevention efforts should frame condom use and other self-protective acts in terms that build upon sex workers own strategies for understanding their options and modifying their risks.