Bayesian response adaptive randomization using longitudinal outcomes

The response adaptive randomization (RAR) method is used to increase the number of patients assigned to more efficacious treatment arms in clinical trials. In many trials evaluating longitudinal patient outcomes, RAR methods based only on the final measurement may not benefit significantly from RAR because of its delayed initiation. We propose a Bayesian RAR method to improve RAR performance by accounting for longitudinal patient outcomes (longitudinal RAR). We use a Bayesian linear mixed effects model to analyze longitudinal continuous patient outcomes for calculating a patient allocation probability. In addition, we aim to mitigate the loss of statistical power because of large patient allocation imbalances by embedding adjusters into the patient allocation probability calculation. Using extensive simulation we compared the operating characteristics of our proposed longitudinal RAR method with those of the RAR method based only on the final measurement and with an equal randomization method. Simulation results showed that our proposed longitudinal RAR method assigned more patients to the presumably superior treatment arm compared with the other two methods. In addition, the embedded adjuster effectively worked to prevent extreme patient allocation imbalances. However, our proposed method may not function adequately when the treatment effect difference is moderate or less, and still needs to be modified to deal with unexpectedly large departures from the presumed longitudinal data model. Copyright © 2015 John Wiley & Sons, Ltd.     

The issues of gender in contemporary Japanese working life: A Japanese “vicious circle”

The aim of this article is to analyze how the gender division of labour has been embodied in the social expectation of women’s roles in urban settings, mainly with respect to married people in contemporary Japan. Especially among Japanese feminist researchers it is much discussed how gender role consciousness and the traditional division of labour have fettered the behaviour of the Japanese—both men and women. I start my discussion by examining the distinction between public and private spheres that seems to be used in different ways by researchers. The gender division of labour functions as a “vicious circle” in hindering possibilities for change, making it more difficult for women to obtain the same primary positions in working life as men and, at the same time, preventing men from enjoying family life as much as women.     

Book reviews

Review Symposium: Cross‐Cultural Roots of Minority Child Development. P.M. Greenfield & R. R. Cocking (Eds.). Hillsdale, NJ: Lawrence Erlbaum, 1994. 431 pp. $89.95, $39.95 (paper).

Understanding Practice. S. Chaiklin and J. Lave (Eds.). Cambridge: Cambridge University Press, 1993. 414 pp. $59.95.     

Simultaneous Tests for Independence Among Components of Random Vector by Step-Down Multiple Comparison Procedure

In this article, we consider testing independence among components of random vector in multivariate normal population. For testing independence, we use the modified likelihood ratio test statistic which is improved an approximation to χ² distribution of the likelihood ratio test statistic. In order to perform simultaneous tests for independence among components of random vector, we use the step-down multiple comparison procedure based on the closed testing procedure proposed by Marcus et al. (1976 Marcus , R. , Peritz , E. , Gabriel , K. R. ( 1976 ). On closed testing procedures with special reference to ordered analysis of variance . Biometrika 63 : 655 – 660 .[Crossref], [Web of Science ®] , [Google Scholar]). Finally, we perform Monte Carlo simulations and present numerical results.     

The role of vole populations in prevalence of the parasite (Echinococcus multilocularis) in foxes

Effects of population fluctuation of the gray-sided vole(Clethrionomys rufocanus) on the prevalence (infection rates) of the parasiteEchinococcus multilocularis in red fox(Vulpes vulpes) populations was investigated from 1985 to 1992 in eastern Hokkaido (Abashiri, Nemuro, and Kushiro area), Japan. This parasite needs two hosts to complete its life cycle; the gray-sided vole as its intermediate host and the red fox as its final host. We found that: (1) Infection rates in foxes depended on the current-year abundance of voles in all three study areas, particularly in Abashiri. (2) In addition to this direct density-dependence, delayed density-dependence between the infection rate and the prior-year abundance of voles was detected in Nemuro and in Kushiro. (3) The regional differences in density-dependence pattern were related to regional differences in the winter food habits of red foxes: in Abashiri the proportion of voles in the fox’s diet greatly decreases in winter, while the proportion remains high in winter in Nemuro and in Kushiro, probably because of shallower snowpack. These results suggest that infection rates in foxes in Abashiri were less influenced by the prior-year prevalence, since the infection cycle might be interrupted in winter, when voles became less important in fox’s diet. In contrast, the state of the prevalence may carry over from year to year in Nemuro and in Kushiro, because red foxes continue to eat a considerable amount of voles throughout year. The regionally contrasted results for the relationship between infection rate in foxes and vole abundance were parallel to the regional difference in fluctuation pattern of vole populations, which are highly variable in Abashiri area, but less variable in Kushiro-Nemuro area. Drastic change in vole populations appears to affect the host-parasite system.     

日本无障碍环境建设理念及推进机制分析

作为世界上人口老龄化最严重的国家,日本在满足老弱病残等弱势群体出行的无障碍环境建设方面走在了世界前列。日本无障碍城市环境体系由设施、系统规划、导向和服务4个要素构成:完备、合理的无障碍设施建设构成这一体系的基础,注重与环境融合的系统性规划将设施有效联通,以全方位的通用设计理念指导信息导向系统设计,并用服务进一步为环境建设查遗补漏。日本无障碍环境建设背后的推进机制以完善的国家无障碍设计法规体系为基石,以优先推动重点发展区域的无障碍建设为实施手段,同时提升国民无障碍环境建设意识、逐步营造良好的社会环境氛围。有效的机制建设是促进日本无障碍城市环境建设的重要推动力量。     

Characterization of probability models by an odds ratio in prospective and retrospective studies

It is shown that, when exposure variables are continuous, the odds ratios are functions of exposure differences if and only if Cox's binary logistic models hold in a prospective framework, and if and only if the underlying distribution belongs to a family of exponential type distributions in a retrospective framework.     

A generalized binomial distribution determined by a two-state Markov chain and a distribution by the Bayesian approach

For dependent Bernoulli random variables, the distribution of a sum of the random variables is obtained as a generalized binomial distribution determined by a two-state Markov chain. Asymptotic distributions of the sum are derived from the central limit theorem and the Edgeworth expansion. A numerical comparison of the exact and asymptotic distributions of the sum is also given. Further a distribution of the sum by the Bayesian approach is derived and its asymptotic distributions are provided. Numerical results are given.     

Truthful Equilibria in Dynamic Bayesian Games

This paper characterizes an equilibrium payoff subset for dynamic Bayesian games as discounting vanishes. Monitoring is imperfect, transitions may depend on actions, types may be correlated, and values may be interdependent. The focus is on equilibria in which players report truthfully. The characterization generalizes that for repeated games, reducing the analysis to static Bayesian games with transfers. With independent private values, the restriction to truthful equilibria is without loss, except for the punishment level: if players withhold their information during punishment‐like phases, a folk theorem obtains.