Assurance in clinical trial design

Conventional clinical trial design involves considerations of power, and sample size is typically chosen to achieve a desired power conditional on a specified treatment effect. In practice, there is considerable uncertainty about what the true underlying treatment effect may be, and so power does not give a good indication of the probability that the trial will demonstrate a positive outcome. Assurance is the unconditional probability that the trial will yield a ‘positive outcome’. A positive outcome usually means a statistically significant result, according to some standard frequentist significance test. The assurance is then the prior expectation of the power, averaged over the prior distribution for the unknown true treatment effect. We argue that assurance is an important measure of the practical utility of a proposed trial, and indeed that it will often be appropriate to choose the size of the sample (and perhaps other aspects of the design) to achieve a desired assurance, rather than to achieve a desired power conditional on an assumed treatment effect. We extend the theory of assurance to two‐sided testing and equivalence trials. We also show that assurance is straightforward to compute in some simple problems of normal, binary and gamma distributed data, and that the method is not restricted to simple conjugate prior distributions for parameters. Several illustrations are given. Copyright © 2005 John Wiley & Sons, Ltd.     

Binge drinking in female college students: the association of physical activity, weight concern, and depressive symptoms

As an initial step in building gender-specific binge drinking intervention programs, the authors investigated the relation of potentially modifiable factors (physical activity level, weight concern, and depressive symptoms) to binge drinking while controlling for the effects of previously established correlates of binge drinking (tobacco and marijuana use, GPA, and perception of peer alcohol use). Four-hundred-twelve college women completed an in-class survey. Multivariate analyses revealed that tobacco and marijuana use, GPA, and physical activity were significantly associated with binge drinking, whereas tobacco use and perception of peers' alcohol use were associated with more frequent binge drinking. The findings suggested that the variables associated with any binge drinking and frequency of binge drinking may differ and that binge drinking can be associated with positive health behaviors (ie, greater physical activity) as well as risky health behaviors (eg, tobacco use).     

Non‐governmental organisations and informal associations in service delivery for African migrants in China: Evidence of voluntary sector failure?

As the Chinese government has purposefully built economic, social and political links with several African states in recent decades, new patterns of international migration have emerged. Notably, mixed‐race families are increasingly visible in southern China, particularly Guangzhou, where there is a concentration of African traders. The few existing studies on this population have failed to pay attention to how, in the absence of state provision of or support for key public resources including health care and education, African‐Chinese families are raising their children. We examined factors contributing to NGO successes and failures in facilitating these families’ wellbeing and integration into mainstream society, drawing on the theory of voluntary sector failure. Mixed‐raced families are relatively isolated from mainstream society as well as formal/informal civil society organisations. We found select features of philanthropic paternalism, philanthropic amateurism, and what we term philanthropic mistrust, with implications for understanding voluntary sector growth in the Chinese context.     

Children's well-being,adult poverty,and jobs-of-last-resort

This article addresses the failure of the 1996 welfare reform act (Personal Responsibility and Work Opportunities Reconciliation Act [PRWORA]) as an anti-poverty program demonstrated by the fact that approximately half of all ‘welfare leavers’ have fallen back into poverty within a year or two of their exit. The proximate cause is that, because of “barriers to work” or insufficient demand, leavers end up working too few hours over the course of a year. To address this failure, we propose a program of jobs-of-last-resort, called Promise of a Job (POJ), based on an examination of the design, costs, and results for a large number of transitional-job and welfare-to-work programs. In this article, we estimate POJ's costs per participant and overall costs of implementation, as well as the impact such a program would have on reducing adult and, particularly, child poverty. We find, in examining past data, that had POJ been applied to just those Americans who were on Aid to Families with Dependent Children (AFDC) in 1996, it would have raised almost 7 million children above the poverty line. We argue that this result (and similar results from any other program) should appeal across the political spectrum, to conservatives and liberals alike, because of the documented general agreement that child poverty is inconsistent with a widely held American value: the provision of equal opportunity for all.     

Organisational Factors,Job Satisfaction and Intention to Leave Among Newly Qualified Social Workers in England

Satisfaction with different organisational elements and aspects of work contributes markedly to overall levels of job satisfaction and intention to leave. For newly qualified social workers (NQSWs), especially immediately after graduation, self-perceived competence and their confidence in their educational preparation are also important. This article reports on a longitudinal study following 280 social work students into social work employment in England using data collected as students and six months after graduation. We focus on their experiences as NQSWs, thus only including those working in social work jobs, reporting the relative importance of their satisfaction with different work elements, such as supervision and job engagement. These are used to construct a model of NQSWs' overall satisfaction and intentions of leaving their social work jobs. The model incorporates NQSWs' perceptions of how well their degree courses prepared them for their current social work jobs in addition to personal, organisational and specific role characteristics. Using statistical techniques of factor analysis and regression modelling we highlight the complexities of how job satisfaction is constructed and we argue that the data reveal the importance of team support and self-efficacy in relation to whether social workers are thinking about leaving their current social work jobs.     

A Comparative Analysis of the Relative Effectiveness of Four Dynamic Lot-Sizing Techniques on Return on Investment

The relative performance of dynamic lot-sizing techniques has been of considerable interest to researchers in recent years. While research has addressed performance in terms of cost-effectiveness, researchers have not determined the impact of dynamic lot-sizing techniques on return on investment (ROI) as it applies to finished goods' schedules. The purpose of this research is to explore the relative performance of four dynamic lot-sizing techniques with regard to ROI, namely the Wagner-Whitin, Incremental Part Period, Silver-Meal, and Groff techniques. Computer graphics are employed to analyze the relative ROI effectiveness.     

Immunization documentation practices and vaccine-preventable disease surveillance capacity among institutions of higher education in Indiana

Objective: Complete and accurate documentation of immunization records and surveillance of disease transmission are critical to the public health response to outbreaks of communicable disease in institutions of higher education (IHEs). This study aims to describe immunization documentation practices and disease surveillance capacity among IHEs in Indiana in order to inform public health action. Methods: IHEs in Indiana were identified and included in the study if they offered on-campus housing and had a dedicated student health center. Phone surveys were administered in September 2015 to each institution, inquiring about current immunization documentation policies and practices, disease surveillance capacity, and use of statewide electronic reporting systems. Additionally, IHE websites were searched to identify immunization documentation requirements for matriculating students. Results: Surveys were completed for 33 of 38 eligible IHEs. Twenty-three (70%) IHEs reported that student immunization records are entered into an accessible electronic system or database. Matriculating student immunization requirements were identified for 32 institutions. Of these, 22 (69%) required a physician-signed proof of immunization. No IHEs reported documenting historical immunizations in the statewide electronic immunization system and three IHEs (9%) reported utilizing the state electronic disease surveillance program. Conclusions: Immunization documentation practices vary among IHEs in Indiana and use of statewide immunization and disease reporting systems is minimal. Robust utilization of immunization and disease surveillance systems has been shown to improve public health response to communicable disease outbreaks. Improving mutual understanding of policy and practice between health departments and IHEs could improve the ability to respond to public health challenges.     

An American Wordless Picturebook in Italian Classrooms: Inspiring Global Connections of People,Places, and Environments

What happens when five teacher candidates and their professor bring a wordless picturebook into Italian classrooms? This article presents a grounded discussion of our immersive experiences from the United States and the minilessons they taught stemming from a piece of children's literature through our study abroad program in Italy. The opening of Italian classroom doors provided reflective observations of the critical and creative thinking processes of more than 200 Italian students (ages 7–16). We (one professor and five early childhood and special education teacher candidates) taught minilessons in five Italian schools during a monthlong study abroad program offered by our university (further described in Author 1, 2017). Although this project was conducted in Italy, we have since used this minilesson successfully in our own classes, and we invite you to adapt our use to fit your teaching.