Tests for noninferiority trials with binomial endpoints: A guide to modern and quasi‐exact methods for biomedical researchers

Applied statisticians and pharmaceutical researchers are frequently involved in the design and analysis of clinical trials where at least one of the outcomes is binary. Treatments are judged by the probability of a positive binary response. A typical example is the noninferiority trial, where it is tested whether a new experimental treatment is practically not inferior to an active comparator with a prespecified margin δ. Except for the special case of δ = 0, no exact conditional test is available although approximate conditional methods (also called second‐order methods) can be applied. However, in some situations, the approximation can be poor and the logical argument for approximate conditioning is not compelling. The alternative is to consider an unconditional approach. Standard methods like the pooled z‐test are already unconditional although approximate. In this article, we review and illustrate unconditional methods with a heavy emphasis on modern methods that can deliver exact, or near exact, results. For noninferiority trials based on either rate difference or rate ratio, our recommendation is to use the so‐called E‐procedure, based on either the score or likelihood ratio statistic. This test is effectively exact, computationally efficient, and respects monotonicity constraints in practice. We support our assertions with a numerical study, and we illustrate the concepts developed in theory with a clinical example in pulmonary oncology; R code to conduct all these analyses is available from the authors.     

Anti‐Americanism,Political Cartoons,and a Socio‐Geographic Imagination: An Invitation to Further Work*

This research note synopsizes previous studies to present future directions for the measurement of anti‐Americanism within the United States and comparatively. We explain new vectors in our research design and posit new hypotheses for future research. The note highlights the importance of cross‐national investigation of anti‐Americanism, and suggests some methodological considerations in that endeavor.     

Multichannel electroencephalographic analyses via dynamic regression models with time-varying lag–lead structure

Multiple time series of scalp electrical potential activity are generated routinely in electroencephalographic (EEG) studies. Such recordings provide important non-invasive data about brain function in human neuropsychiatric disorders. Analyses of EEG traces aim to isolate characteristics of their spatiotemporal dynamics that may be useful in diagnosis, or may improve the understanding of the underlying neurophysiology or may improve treatment through identifying predictors and indicators of clinical outcomes. We discuss the development and application of non-stationary time series models for multiple EEG series generated from individual subjects in a clinical neuropsychiatric setting. The subjects are depressed patients experiencing generalized tonic–clonic seizures elicited by electroconvulsive therapy (ECT) as antidepressant treatment. Two varieties of models—dynamic latent factor models and dynamic regression models—are introduced and studied. We discuss model motivation and form, and aspects of statistical analysis including parameter identifiability, posterior inference and implementation of these models via Markov chain Monte Carlo techniques. In an application to the analysis of a typical set of 19 EEG series recorded during an ECT seizure at different locations over a patient's scalp, these models reveal time-varying features across the series that are strongly related to the placement of the electrodes. We illustrate various model outputs, the exploration of such time-varying spatial structure and its relevance in the ECT study, and in basic EEG research in general.     

Bayesian Dynamic Factor Models and Portfolio Allocation

We discuss the development of dynamic factor models for multivariate financial time series, and the incorporation of stochastic volatility components for latent factor processes. Bayesian inference and computation is developed and explored in a study of the dynamic factor structure of daily spot exchange rates for a selection of international currencies. The models are direct generalizations of univariate stochastic volatility models and represent specific varieties of models recently discussed in the growing multivariate stochastic volatility literature. We discuss model fitting based on retrospective data and sequential analysis for forward filtering and short-term forecasting. Analyses are compared with results from the much simpler method of dynamic variance-matrix discounting that, for over a decade, has been a standard approach in applied financial econometrics. We study these models in analysis, forecasting, and sequential portfolio allocation for a selected set of international exchange-rate-return time series. Our goals are to understand a range of modeling questions arising in using these factor models and to explore empirical performance in portfolio construction relative to discount approaches. We report on our experiences and conclude with comments about the practical utility of structured factor models and on future potential model extensions.     

Rear gunners and troubled privates: Wordplay in a dick joke competition1

A humorous competition called ‘The Adventures of Naked Man’ ran in a Wellington (New Zealand) newspaper from 1999 to 2000. The competition's protagonist is the sole naked person in a drawn setting where, because of some convenient object or body position, his penis is obscured from sight. Entrants to the competition submitted a caption to go with the drawn setting, the point being to make humour. Without explicit instruction, most entrants constructed some form of dick joke, the interesting questions being, just how, and with what variations? These questions are pursued by drawing on the full corpus of Naked Man settings and captions. Basic principles of conversation analysis, including some early work of Sacks on punning, are used to analyse the nature and popularity of the Naked Man competition. The article also offers some more speculative comments to do with gender and the organisation of language about sexuality.     

Using the 2001 census to study human capital movements affecting Britain's larger cities: insights and issues

Summary.  Human capital is increasingly being recognized as crucial to the sustained growth of British cities, and the population census is unrivalled as a source of data on the characteristics of people moving to and from cities. Taking advantage of new features in the 2001 census, the paper examines how successful 27 of Britain's largest cities and their regions are in maintaining their labour force complement, giving particular attention to young adults and people working in high level occupations. Considerable variation is apparent between city regions, but the interpretation of results is somewhat hampered by limitations in the census data, prompting recommendations for future data collection.     

EXACT P‐VALUES FOR DISCRETE MODELS OBTAINED BY ESTIMATION AND MAXIMIZATION

In constructing exact tests from discrete data, one must deal with the possible dependence of the P‐value on nuisance parameter(s) ψ as well as the discreteness of the sample space. A classical but heavy‐handed approach is to maximize over ψ. We prove what has previously been understood informally, namely that maximization produces the unique and smallest possible P‐value subject to the ordering induced by the underlying test statistic and test validity. On the other hand, allowing for the worst case will be more attractive when the P‐value is less dependent on ψ. We investigate the extent to which estimating ψ under the null reduces this dependence. An approach somewhere between full maximization and estimation is partial maximization, with appropriate penalty, as introduced by Berger & Boos (1994, P values maximized over a confidence set for the nuisance parameter. J. Amer. Statist. Assoc. 89 , 1012–1016). It is argued that estimation followed by maximization is an attractive, but computationally more demanding, alternative to partial maximization. We illustrate the ideas on a range of low‐dimensional but important examples for which the alternative methods can be investigated completely numerically.     

The link between parenting approaches and health behavior: A systematic review

The familial home environment, where parenting takes place, plays an important role in the health behaviors that children and adolescents engage in and has implications on health and well-being in later life. Lifestyle-related behaviors predispose children and adolescents to the global burden of non-communicable and other lifestyle-related diseases. This review therefore examined and described previous studies looking at the associations between health behaviors and parenting approaches. It suggests that engagement in health behaviors, which promotes overall health and well-being, was associated with autonomy, supportive parenting, parental encouragement, behavior control, parental nurturance, warmth and responsiveness, and parental involvement. The review highlights the gap in literature focusing on the health behavior of children and adolescents as well as on parenting. In addition, the review also provides an overview of the continents where fewer studies have examined the presented associations. The findings presented also serve as a guide for program development and implementation to address the increase in non-communicable and other lifestyle-related diseases.     

Performance measurement frameworks in public and non-profit sectors

In the last decade much attention has been devoted to developing performance measurement systems (PMS), which could encompass both financial and non-financial measures. Many frameworks have been conceived in order to allow companies to better evaluate their own performance by means of collected data, but few attempts have been made to provide public and non-profit organizations with PMS devoted explicitly for their needs. The aims of this paper are to review the frameworks currently developed and implemented in public and non-profit organizations and to identify the requirements of a framework, which can be applied in this context.