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二元生存函数的自洽非参数最大似然估计AI 解读

As usually formulated the nonparametric likelihood for the bivariate survivor function is over-parameterized, resulting in uniqueness problems for the corresponding nonparametric maximum likelihood estimator. Here the estimation problem is redefined to include parameters for marginal hazard rates, and for double failure hazard rates only at informative uncensored failure time grid points where there is pertinent empirical information. Double failure hazard rates at other…

基因组范围基因—环境交互的独立筛选两阶段检验AI 解读

Several two-stage multiple testing procedures have been proposed to detect gene-environment interaction in genome-wide association studies. In this article, we elucidate general conditions that are required for validity and power of these procedures, and we propose extensions of two-stage procedures using the case-only estimator of gene-treatment interaction in randomized clinical trials. We develop a unified estimating equation approach to proving asymptotic independence…

二元生存数据正态变换模型的半参数极大似然估计AI 解读

We consider a class of semiparametric normal transformation models for right censored bivariate failure times. Nonparametric hazard rate models are transformed to a standard normal model and a joint normal distribution is assumed for the bivariate vector of transformed variates. A semiparametric maximum likelihood estimation procedure is developed for estimating the marginal survival distribution and the pairwise correlation parameters. This produces an efficient estimator…

基于相关失效时间数据的风险比参数估计方程AI 解读

Weighted partial likelihood estimating equations are proposed for the estimation of marginal hazard ratio parameters based on correlated failure time data. Asymptotic distribution theory is derived for the solution to such equations using martingale convergence results and inverse function theory. Simulation studies and theoretical efficiency calculations indicate that the inclusion of weights in the estimating equation produces important efficiency gains only if the…

疾病风险因素的汇总数据研究AI 解读

Statistical methods are proposed for estimating relative rate parameters, based on estimated disease rates and covariate data from random samples of individuals from each of several cohorts. A random effects model is used to derive mean and variance models for estimated disease rates. Estimating equations for relative rate parameters are then developed by replacing cohort covariate averages by corresponding sample averages. The asymptotic distribution of regression parameter…

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删失多元失效时间数据的协方差与生存函数估计AI 解读

The covariance between counting process martingales is used to characterize the dependence between two failure time variates. A representation of the bivariate survivor function is obtained in terms of the marginal survivor functions and this covariance function. A closely related representation expresses the bivariate survivor function in terms of marginal survivor functions and a conditional covariance function, leading to a new nonparametric survivor function estimator.…

删失多元失效时间数据的协方差与生存函数估计AI 解读

The covariance between counting process martingales is used to characterize the dependence between two failure time variates. A representation of the bivariate survivor function is obtained in terms of the marginal survivor functions and this covariance function. A closely related representation expresses the bivariate survivor function in terms of marginal survivor functions and a conditional covariance function, leading to a new nonparametric survivor function estimator.…

扩展贝塔二项分布的二元回归及协变量测量误差诱发的相关性AI 解读

The beta-binomial distribution is extended to allow negative correlations among binary variates within an experimental unit. Regression models are proposed for both the binary variate response rate and for the pairwise correlation between binary variates, and corresponding likelihood estimation procedures are described. Binary regression problems are also considered, in which measurement errors in the regression variables represent the sole source of overdispersion. Some…

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失效时间回归模型中的协变量测量误差与参数估计AI 解读

Estimation in Cox's failure time regression model is considered when the regression vector is subject to measurement error. A hazard function model is induced for the failure rate given the measured covariate and a partial likelihood function is derived for the relative risk parameters. This partial likelihood function may involve the baseline hazard function as well as the regression parameter, but useful inference techniques arise for testing whether the regression…

多元失效时间数据的回归分析AI 解读

The paper is concerned with the analysis of regression effects when individual study subjects may experience multiple failures. The proposed methods are most likely to be useful when there are a fairly large number of study subjects. Two general classes of regression models are considered in order to relate the hazard or intensity function to covariates and to preceding failure time history. Both models are of a stratified proportional hazards type. One model includes…

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偏似然近似：侧重病例对照研究AI 解读

For many case-control applications, previously suggested approximations to Cox's (1972, 1975) partial likelihood in prospective applications are shown to be seriously inadequate. Alternative approximations based on unconditional maximum likelihood estimation and Taylor series expansion are developed and shown to yield an improvement over the previous methods. In particular, an approximation to the maximum partial likelihood estimator is proposed using the log partial…

疾病发生的 Logistic 模型与病例对照研究AI 解读

The probability of disease development in a defined time period is described by a logistic regression model. A model for the regression variable, given disease status, is induced and is applied to case-control data. It is shown that the odds ratio estimators and their asymptotic variance matrices may be obtained by applying the original logistic regression model to the case-control study as if the data had been obtained in a prospective study. This result gives a flexible…

右删失数据的线性秩检验AI 解读

Linear rank statistics are developed for tests on regression coefficients with censored data. These statistics arise as score statistics based on the marginal probability of a generalized rank vector. The observed Fisher information provides a variance estimator generally, while in certain special cases a permutation approach to variance estimation is also possible. The Wilcoxon test is generalized to regression tests with censored data. The log rank test (Cox, 1972; Peto &…

右删失数据的线性秩检验AI 解读

Linear rank statistics are developed for tests on regression coefficients with censored data. These statistics arise as score statistics based on the marginal probability of a generalized rank vector. The observed Fisher information provides a variance estimator generally, while in certain special cases a permutation approach to variance estimation is also possible. The Wilcoxon test is generalized to regression tests with censored data. The log rank test (Cox, 1972; Peto &…

对数伽马模型及其最大似然估计AI 解读

A three parameter model is developed by reparameterizing and extending the distribution of the logarithm of a generalized gamma variate. The extreme value distributions for maxima and minima are included while the normal distribution is central. Asymptotic maximum likelihood theory is given and maximum likelihood distributions are studied, via simulation, in some special cases. A regression generalization is given.

含删失与解释变量的指数生存模型AI 解读

Consideration is given to the analysis of survival times, censored and uncensored, arising from a hazard function that varies exponentially with covariates and is otherwise constant. Significance tests and statements of probabilistic inference are derived for covariate parameters and for the hazard function at average values of the covariate. The results are extended to include a Weibull component in the hazard. Clinical trials on advanced lung cancer patients serve to…

含删失与解释变量的指数生存模型AI 解读

Consideration is given to the analysis of survival times, censored and uncensored, arising from a hazard function that varies exponentially with covariates and is otherwise constant. Significance tests and statements of probabilistic inference are derived for covariate parameters and for the hazard function at average values of the covariate. The results are extended to include a Weibull component in the hazard. Clinical trials on advanced lung cancer patients serve to…

Marginal likelihoods are obtained for the regression parameters in the model presented by Cox (1972). If no ties occur in the recording of failure time data the results of Cox are given a straightforward justification. If ties occur in the data, results different from those suggested by Cox are obtained. Some Monte-Carlo comparisons of these competing results are made. A discrete model is developed for grouped data from Cox's model and estimates of the survivor function are…