Randomized response multivariate designs for categorical data

Three approaches to multivariate estimation for categorical data using randomized response (RR) are described. In the first approach, practical only for 2×2 contingency tables, a multi-proportions design is used. In the second approach, a separate RR trial is used for each variate and it is noted that the multi­variate design matrix of conditional probabilities is given by the Kroneeker product of the univariate design matrices of each trial, provided that the trials are independent of each other in a certain sense. The third approach requires only a single randomization and thus may be viewed as the use of vector response. Finally, a special-purpose bivariate design is presented.     

Three methods of constructing pbib designs

Three construction methods of two- or three-associate partially balanced incomplete block (PBIB) designs are presented.     

Analytic expressions for maximum likelihood estimators in a nonparametric model of tumor incidence and death

This research focuses on the estimation of tumor incidence rates from long-term animal studies which incorporate interim sacrifices. A nonparametric stochastic model is described with transition rates between states corresponding to the tumor incidence rate, the overall death rate, and the death rate for tumor-free animals. Exact analytic solutions for the maximum likelihood estimators of the hazard rates are presented, and their application to data from a long-term animal study is illustrated by an example. Unlike many common methods for estimation and comparison of tumor incidence rates among treatment groups, the estimators derived in this paper require no assumptions regarding tumor lethality or treatment lethality. The small sample operating characteristics of these estimators are evaluated using Monte Carlo simulation studies.     

Posterior moments of scalar functions of a covariance matrix

Given multivariate normal data and a certain spherically invariant prior distribution on the covariance matrix, it is desired to estimate the moments of the posterior marginal distributions of some scalar functions of the covariance matrix by importance sampling. To this end a family of distributions is defined on the group of orthogonal matrices and a procedure is proposed for selecting one of these distributions for use as a weighting distribution in the importance sampling process. In an example estimates are calculated for the posterior mean and variance of each element in the covariance matrix expressed in the original coordinates, for the posterior mean of each element in the correlation matrix expressed in the original coordinates, and for the posterior mean of each element in the covariance matrix expressed in the coordinates of the principal variables.     

我国公共支出归宿研究：以医疗保险补贴为例

我国医疗服务和产品市场的开放,医疗机构数量的增加,带动了医疗供给弹性变大以及国家对居民医疗消费的报销方式的改变。在财政补贴居民参加医疗保险时影响公共支出归宿的因素有多种。应通过提高医疗服务的供给价格弹性、降低居民对医疗服务的需求价格弹性等途径,使居民成为参加医疗保险补贴归宿的最大受益者。由此,国家通过建立新型农村合作医疗制度和城镇居民基本医疗保险,降低居民医疗支出负担的政策目标才能最终得到实现。     

Hermite块复合矩阵的块特征值

讨论了块复合矩阵的块特征值的性质和块特征向量的正交性问题 ,得到了Hermite块复合矩阵的块特征值和块特征向量的一系列结论     

Estimation of conditional cumulative incidence functions under generalized semiparametric regression models with missing covariates,with application to analysis of biomarker correlates in vaccine trials

This article presents generalized semiparametric regression models for conditional cumulative incidence functions with competing risks data when covariates are missing by sampling design or happenstance. A doubly robust augmented inverse probability weighted (AIPW) complete-case approach to estimation and inference is investigated. This approach modifies IPW complete-case estimating equations by exploiting the key features in the relationship between the missing covariates and the phase-one data to improve efficiency. An iterative numerical procedure is derived to solve the nonlinear estimating equations. The asymptotic properties of the proposed estimators are established. A simulation study examining the finite-sample performances of the proposed estimators shows that the AIPW estimators are more efficient than the IPW estimators. The developed method is applied to the RV144 HIV-1 vaccine efficacy trial to investigate vaccine-induced IgG binding antibodies to HIV-1 as correlates of acquisition of HIV-1 infection while taking account of whether the HIV-1 sequences are near or far from the HIV-1 sequences represented in the vaccine construct.     

突发公共卫生事件中实施药品专利强制许可的思考

人感染高致病性禽流感疫情在世界多个国家的传播,不仅对社会大众健康产生了威胁,而且更加凸显药品专利保护与公众健康需要之间的矛盾,药品专利强制许可无疑是解决这个矛盾的一条途径。文章对药品专利强制许可的背景、理论进行了分析,指出了目前实施这一许可的障碍,并提出了相应的对策。