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广义线性模型均值函数的失拟检验AI 解读

A supremum-type statistic, based on partial sums of residuals, is proposed to test the validity of the mean function of the response variable in a generalized linear model. The proposed test does not need a partition of the space of covariates to handle the case of nonreplication. The new test is consistent against the alternative, under which the deterministic part of the model is not the one specified in the null hypothesis. The asymptotic null distribution of the test…

基于秩检验的删失生存数据线性回归分析AI 解读

Recently linear rank statistics with censored data have been used as the estimating functions for the regression parameters in the linear model with an unspecified error distribution. The resulting rank estimators are consistent and asymptotically normal. However, the asymptotic variances of these estimators are complicated and are difficult to estimate well with censored data. In this paper, we propose some simple methods for making inference about a subset of the…

数据依赖型治疗分配规则下的统计推断AI 解读

In comparing two treatments with dichotomous responses, the randomized play-the-winner rule (Wei and Durham 1978) tends to assign more study subjects to the better treatment. For ethical reasons, this property is desirable for studies on human subjects. The randomized play-the-winner rule, which is a modification of Zelen's play-the-winner rule (Zelen 1969), is not deterministic and is less vulnerable to experimental bias than other adaptive designs. Recently, this design…

基于秩检验的删失生存数据线性回归分析AI 解读

Recently linear rank statistics with censored data have been used as the estimating functions for the regression parameters in the linear model with an unspecified error distribution. The resulting rank estimators are consistent and asymptotically normal. However, the asymptotic variances of these estimators are complicated and are difficult to estimate well with censored data. In this paper, we propose some simple methods for making inference about a subset of the…

Cox 比例风险模型的稳健推断AI 解读

We derive the asymptotic distribution of the maximum partial likelihood estimator β for the vector of regression coefficients β under a possibly misspecified Cox proportional hazards model. As in the parametric setting, this estimator β converges to a well-defined constant vector β*. In addition, the random vector n 1/2(β – β*) is asymptotically normal with mean 0 and with a covariance matrix that can be consistently estimated. The newly proposed robust covariance matrix…

通过边际分布建模分析多元不完整失效时间数据AI 解读

Many survival studies record the times to two or more distinct failures on each subject. The failures may be events of different natures or may be repetitions of the same kind of event. In this article, we consider the regression analysis of such multivariate failure time observations. Each marginal distribution of the failure times is formulated by a Cox proportional hazards model. No specific structure of dependence among the distinct failure times on each subject is…

受限随机分配规则下的区间估计AI 解读

In comparing two treatments in a clinical trial, suppose that patients are assigned sequentially to treatments by a restricted randomization rule. Exact and approximate confidence intervals for treatment difference are derived without assuming that the study subjects were obtained by random sampling from a well-defined population. We show that, if there is a time trend among the responses of study subjects, one should not ignore the design in the analysis. All the procedures…

受限随机分配规则下的区间估计AI 解读

In comparing two treatments in a clinical trial, suppose that patients are assigned sequentially to treatments by a restricted randomization rule. Exact and approximate confidence intervals for treatment difference are derived without assuming that the study subjects were obtained by random sampling from a well-defined population. We show that, if there is a time trend among the responses of study subjects, one should not ignore the design in the analysis. All the procedures…

具有二维可交换观测的两样本问题AI 解读

SUMMARY In comparing two groups of subjects, suppose that each subject has two observations which are probabilistically exchangeable. Univariate rank tests which utilize this symmetry property are proposed for testing the equality of the two groups. Efficiencies of these tests are discussed. Point and interval estimators of the location shift parameter are obtained through the proposed rank tests. Examples are also provided to illustrate the proposed procedures.

临床试验中受限随机化规则下的多处理比较AI 解读

In the course of conducting a clinical trial to compare $K (\geq 2)$ treatments, it is often desirable to balance the trial with respect to the assignments of patients to treatments. On the other hand, some form of randomization of treatment assignments is essential for reducing experimental bias. In this article, the large-sample approximation to the null distribution of $K$-sample randomization tests generated from a broad class of restricted randomization rules is…

不完整重复测量下的相关检验合并AI 解读

In comparing the effectiveness of two treatments, repeated measurements of the same characteristic are often taken under two or more distinct conditions for each experimental subject. A locally best linear combination of individual test statistics obtained under different conditions is proposed to test the equality of the two treatments. The test procedure allows different patterns of missing observations for the two groups to be compared. Special cases such as combining…

删失配对数据中位置差的无分布估计方法AI 解读

Nonparametric point and interval estimators of location difference in matched pairs data with arbitrary right censorship are proposed, based on a generalized Gehan—Gilbert test (Wei 1980). The point estimator is shown to be asymptotically normal and strongly consistent. The limits of the corresponding interval estimator are readily computable. An example is also provided to illustrate the techniques to problems in survival data analysis.

右删失配对数据位置差的分布无关估计AI 解读

Nonparametric point and interval estimators of location difference in matched pairs data with arbitrary right censorship are proposed, based on a generalized Gehan—Gilbert test (Wei 1980). The point estimator is shown to be asymptotically normal and strongly consistent. The limits of the corresponding interval estimator are readily computable. An example is also provided to illustrate the techniques to problems in survival data analysis.

不完整重复测量下相关检验的合并AI 解读

In comparing the effectiveness of two treatments, repeated measurements of the same characteristic are often taken under two or more distinct conditions for each experimental subject. A locally best linear combination of individual test statistics obtained under different conditions is proposed to test the equality of the two treatments. The test procedure allows different patterns of missing observations for the two groups to be compared. Special cases such as combining…

不完整多元观测的两样本渐近分布无关检验AI 解读

Asymptotically distribution-free tests for equality of two multivariate distributions based on censored observations are proposed. By choosing appropriate test scores, we obtain the multivariate versions of the Gehan and log-rank tests. An important application of the proposed tests is in the area in which multiple observations are collected on study subjects, some of whom may have missing observations. The patterns of missing observations are allowed to differ for the two…

随机删失观测下比例风险模型的拟合优度检验AI 解读

A numerical omnibus test of fit for the two-sample proportional hazards model is proposed for randomly censored observations. The test is derived from Cox's partial likelihood and does not need a dummy time-dependent covariate or any partition of the time-axis. Consistency of the test is established. Examples are provided for illustration.

不完整配对观测下的可互换性检验AI 解读

A class of conditionally distribution-free rank order tests is developed for testing interchangeability of two correlated variates with incomplete data on both responses. Asymptotic properties of these tests are examined. In particular, we show that the proposed tests are also asymptotically distribution-free. For location alternatives, the Pitman efficiency of the rank order test relative to the parametric test based on the bivariate normal model is investigated.

A class of conditionally distribution-free rank order tests is developed for testing interchangeability of two correlated variates with incomplete data on both responses. Asymptotic properties of these tests are examined. In particular, we show that the proposed tests are also asymptotically distribution-free. For location alternatives, the Pitman efficiency of the rank order test relative to the parametric test based on the bivariate normal model is investigated.

受限随机化设计下的显著性检验AI 解读

Experimental subjects are assigned to one of two treatments sequentially by restricted randomization assignment rules. Significance tests generated from these rules are discussed. Under rather mild conditions on the test scores the asymptotic null permutational distribution of tests based on the urn design (Wei, 1977, 1978a) is shown to be normal.

右删失观测下尺度变化的非参数估计AI 解读

Nonparametric point and interval estimators of the ratio of two scale parameters are given for arbitrarily right-censored data based on the idea of Hodges and Lehmann (1963). These estimators are defined in terms of rank test statistics for testing the equality of two survival distributions. The asymptotic properties and efficiencies of estimators corresponding to the tests studied by Gill (1980) are investigated.

受限随机化设计下的显著性检验AI 解读

Experimental subjects are assigned to one of two treatments sequentially by restricted randomization assignment rules. Significance tests generated from these rules are discussed. Under rather mild conditions on the test scores the asymptotic null permutational distribution of tests based on the urn design (Wei, 1977, 1978a) is shown to be normal.

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基于修正 Wilcoxon 统计量的两样本重复显著性检验AI 解读

The asymptotic distribution theory of sequentially computed modified-Wilcoxon scores is developed for two-sample survival data with random staggered entry and random loss to follow-up. The asymptotic covariance indicates generally dependent modified-Wilcoxon increments, contradicting (the authors' reading of) Jones and Whitehead (1979). A repeated significance testing procedure is presented for testing the equality of two survival distributions based on the asymptotic…

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