Adaptive designs for single‐arm phase II trials in oncology

Clinical phase II trials in oncology are conducted to determine whether the activity of a new anticancer treatment is promising enough to merit further investigation. Two‐stage designs are commonly used for this situation to allow for early termination. Designs proposed in the literature so far have the common drawback that the sample sizes for the two stages have to be specified in the protocol and have to be adhered to strictly during the course of the trial. As a consequence, designs that allow a higher extent of flexibility are desirable. In this article, we propose a new adaptive method that allows an arbitrary modification of the sample size of the second stage using the results of the interim analysis or external information while controlling the type I error rate. If the sample size is not changed during the trial, the proposed design shows very similar characteristics to the optimal two‐stage design proposed by Chang et al. (Biometrics 1987; 43:865–874). However, the new design allows the use of mid‐course information for the planning of the second stage, thus meeting practical requirements when performing clinical phase II trials in oncology. Copyright © 2012 John Wiley & Sons, Ltd.     

Pension reforms in EU11 countries: An evaluation of post‐socialist pension policies

This article evaluates the pension policy pathways of the 11 former state socialist nations that have joined the European Union since 2004. Focusing primarily on the post‐2004 period, the analysis discusses the most important measurable outcomes of these countries’ pension reforms, in terms of poverty alleviation, pension adequacy and fiscal sustainability. Going beyond the quantifiable concepts, we also investigate the quality of the 11 countries’ pension systems in terms of equity as well as efficiency, emphasizing the less conspicuous design errors present in these systems. Although these errors have received little attention to date, they may harm pension schemes along several dimensions, including their fiscal sustainability.     

Explaining Accessibility and Satisfaction Related to Healthcare: A Mixed-Methods Approach

Accessibility and satisfaction related to healthcare services are conceived as multidimensional concepts. These concepts can be studied using objective and subjective measures. In this study, we created two indices: a composite healthcare accessibility index (CHCA) and a composite healthcare satisfaction index (CHCS). To calculate the CHCA index we used three indicators based on three components of multidimensional healthcare accessibility: availability, acceptability and accessibility. In the indicator based on the component of accessibility, we included an innovative perceived time-decay parameter. The three indicators of the CHCA index were weighted through the application of a principal components analysis. To calculate the CHCS index, we used three indicators: the waiting time after the patient arrives at the healthcare service, the quality of the healthcare, and the healthcare service supply. These three indicators making up the CHCA index were weighted by applying an analytical hierarchy process. Three kinds of regressions were subsequently applied in order to explain the CHCA and CHCS indices: namely the Linear Least Squares, Ordinal Logistic, and Random Forests regressions. In these regressions, we used different independent social and health-related variables. These variables represented the predisposing, enabling, and need factors of people´s behaviors related to healthcare. All the calculations were applied to a study area: the city of Quito, Ecuador. Results showed that there are health-related inequalities in regard to healthcare accessibility and healthcare satisfaction in our study area. We also identified specific social factors that explained the indices developed. The present work is a mixed-methods approach to evaluate multidimensional healthcare accessibility and healthcare satisfaction, incorporating a pluralistic perspective, as well as a multidisciplinary framework. The results obtained can also be considered as tools for healthcare and urban planners, for more integrative social analyses that can improve the quality of life in urban residents.     

Die Bedeutung der Zinsschranke

The German Corporate Tax Reform Act of 2008 requires an adjustment of classic valuation concepts because it limits interest deduction from taxable income depending on the operating performance of the company. By using time- and state-contingent discount rates in a risk-neutral valuation with predetermined debt levels, a theoretically sound valuation result is obtained. However, a modified APV-concept which assumes deterministic debt over the planning horizon and constant leverage in the terminal value phase also yields consistent valuation results when two types of tax shields with different levels of risk are distinguished.     

Affine LIBOR models driven by real-valued affine processes

The class of affine LIBOR models is appealing since it satisfies three central requirements of interest rate modeling. It is arbitrage-free, interest rates are nonnegative, and caplet and swaption prices can be calculated analytically. In order to guarantee nonnegative interest rates affine LIBOR models are driven by nonnegative affine processes, a restriction that makes it hard to produce volatility smiles. We modify the affine LIBOR models in such a way that real-valued affine processes can be used without destroying the nonnegativity of interest rates. Numerical examples show that in this class of models, pronounced volatility smiles are possible.     

Bindung(en) in der Arbeitswelt

Vanishing or decreasing attachment is an indicator for changes within a work-oriented society. This particularly affects employment and our organizational commitment as well as bonds that are established in the context of professional relationships. This text provides a comparative analysis of two attachment-theoretical approaches that have developed simultaneously but independently from one another: commitment research into organizational psychology on the one hand and attachment theory based on developmental psychology on the other. Both are to be examined for their potential, their theoretical and empirical response to current dynamics in the world of work.     

Das TIMP-Inventar – Ein Beitrag zur ökonomischen Erfassung von Kern-Faktoren salutogener Führung

Occupational health management and science increasingly focus on the issue of health-promoting leadership. Meanwhile a lot of leadership behaviors have been identified that affect the health of employees. To measure them requires high costs. Therefore, the aim of this study is to identify core-factors of salutogenic leadership and to operationalize them for an efficient diagnosis. As an integrative work-related indicator of employees’ health sense of work coherence (Work-SoC) was chosen. In a deductive and inductive process the TIMP-inventory has been developed that enables the economic assessment of three leadership dimensions: Trust, Incident Management and Pressure. These factors explain with less items more variance of the Work-SoC construct than established general and health-related leadership scales of transformational leadership, consideration, social support, demanding leadership as well as positive and negative health behavior. That is why the TIMP-factors can be recognized as core-factors of health-promoting leadership.