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利用二元数据测量潜在亚组的变化：三类极大似然估计AI 解读

Changes in dichotomous data caused by treatments can be analyzed by means of the so-called linear logistic model with relaxed assumptions (LLRA). In contrast to models of the Rasch type, the LLRA allows incidental multidimensional parameters describing the response behavior of the subjects so that each observable criterion used for assessing the changes is governed by its own subject parameter. Because generalizability of the treatment effects over subjects and criteria is…

样本调查中无回答处理的一则讨论AI 解读

Two distinct types of models are used for handling nonresponse in survey sampling theory. In a response (or quasi-randomization) model, the propensity of survey response is modeled as a random process, an additional phase of sample selection. In a parametric (or superpopulation) model, the survey data are themselves modeled. These two models can be used simultaneously in the estimation of a population mean so that one provides some protection against the potential for…

随机缺失数据下均值泛函的非参数估计AI 解读

This article considers a distribution-free estimation procedure for a basic pattern of missing data that often arises from the wellknown double sampling in survey methodology. Without parametric modeling of the missing mechanism or the joint distribution, kernel regression estimators are used to estimate mean functionals through empirical estimation of the missing pattern. A generalization of the method of Cheng and Wei is verified under the assumption of missing at random.…

局部平均处理效应的识别与估计AI 解读

We investigate conditions sufficient for identification of average treatment effects using instrumental variables. First we show that the existence of valid instruments is not sufficient to identify any meaningful average treatment effect. We then establish that the combination of an instrument and a condition on the relation between the instrument and the participation status is sufficient for identification of a local average treatment effect for those who can be induced…

基于加权残差的比例风险检验与诊断AI 解读

SUMMARY Nonproportional hazards can often be expressed by extending the Cox model to include time varying coefficients; e.g., for a single covariate, the hazard function for subject i is modelled as exp { fl(t)Zi(t)}. A common example is a treatment effect that decreases with time. We show that the function /3(t) can be directly visualized by smoothing an appropriate residual plot. Also, many tests of proportional hazards, including those of Cox (1972), Gill & Schumacher…

响应自适应治疗分配设计下的渐近推断AI 解读

A response-adaptive treatment allocation design for a clinical trial attempts to place the majority of patients on the treatment that appears more successful, based on the responses of patients already treated. One example of such a design is the randomized play-the-winner rule developed by Wei and Durham, which randomizes the treatment assignment probabilities according to the outcomes of treatments previously assigned. For a trial with dichotomous treatment responses and a…

观察性研究中处理效应的Hodges–Lehmann点估计AI 解读

A Hodges-Lehmann point estimate of an additive treatment effect is a robust estimate derived from the randomization distribution of a rank test. This article shows how to carry out a sensitivity analysis for such an estimate in an observational study where treatments are not randomly assigned. Two cases are discussed in detail: matched pairs and the comparison of two unmatched groups. The method uses a model for the distribution of treatment assignments when hidden biases…

观察研究中治疗效应的 Hodges–Lehmann 点估计AI 解读

A Hodges-Lehmann point estimate of an additive treatment effect is a robust estimate derived from the randomization distribution of a rank test. This article shows how to carry out a sensitivity analysis for such an estimate in an observational study where treatments are not randomly assigned. Two cases are discussed in detail: matched pairs and the comparison of two unmatched groups. The method uses a model for the distribution of treatment assignments when hidden biases…

利用替代失效时间数据提高临床试验的成本效益AI 解读

In clinical trials with failure time, outcomes, the cost of follow-up for the endpoint of primary interest is sometimes expensive. In many of these settings, one or more secondary or surrogate failure time outcomes are also available which either occur much earlier or are much less expensive to follow than the primary outcome. This paper presents a method for using these secondary outcomes to increase the power of detecting a treatment effect on the primary outcome only,…

用几何方法评估广义线性模型中的遗漏协变量偏差AI 解读

Misspecifying generalized linear models by omitting covariates associated with the response can result in seriously biased estimates of the effects of the included covariates. For certain models, such bias can occur even when the omitted covariate is independent of the included covariates, as in studies with randomized treatment assignment. This paper presents a geometric approach to assess the direction of the bias resulting from omitted covariates and develop intuition…

合并独立检验的若干统计程序AI 解读

In many applications available data from several independent studies address the same question, and it is essential to have statistical methods for combining the results from the different studies. This article addresses this issue in two setups: (1) a testing hypothesis concerning the common mean vector of two independent linear models having different variances, and (2) a testing hypothesis concerning a common variance component in linear models involving two variance…

多个位置参数极差的置信上界构造AI 解读

This article considers the construction of an upper confidence bound on the range of a set of k location parameters, such as the k treatment effects in a one-way layout. This confidence bound will be useful to the experimenter in assessing the “equivalence” of the location parameters. Some general theoretical results are presented and the case of normally distributed data is considered in detail, with accompanying tables of confidence bounds. Some examples of the application…

大麻非刑事化对医院急诊涉药事件的影响：1975—1978年AI 解读

Between 1973 and 1978, 12 states with collectively over one-third of the total U.S. population enacted laws that decriminalized the possession of marijuana. This article uses standard metropolitan statistical area (SMSA) level data on hospital emergency room drug episodes collected by the Drug Abuse Warning Network to measure the effect of changes in drug penalties on substance abuse crises. The regression models demonstrate that marijuana decriminalization was accompanied…

作为实践问题的季节调整AI 解读

Seasonal adjustment as a practical problem. Prolegomena to actual seasonal adjustment. Mechanical seasonal adjustment methods. ARIMA models and seasonal adjustment. Structural time series models and seasonal adjustment. The adding up problem and seasonally adjusted monetary analysis. Causal methods of seasonal adjustment. Concluding observations. Annex. References. Indexes.

用抽样调查与时间序列干预分析评估反酒驾广告活动AI 解读

The impact of a paid advertising campaign targeted at reducing youthful male drinking-driving behavior is examined using (1) pretest and posttest sample surveys taken at both a campaign site and a control site and (2) time series intervention modeling of monthly traffic accident data from both sites. These compatible analyses provide collaborative evidence that the advertising campaign reduced youthful male drinking and driving behavior and, consequently, traffic accidents.

删失配对数据的再删失方法AI 解读

In comparing two treatment regimens, a matched-pair design is often used for nonhomogeneous experimental units. A standard method of analyzing the resulting data is to consider the difference within pairs, so that the nuisance parameters due to the heterogeneity between pairs can be eliminated and the parameter of interest—the treatment effect—can be estimated. This procedure becomes invalid when the data are subject to censoring, however. In addition, the available…

因果型空间自回归过程估计量的偏差AI 解读

We study the asymptotic distribution of Yule-Walker and least squares estimators for twodimensional causal autoregressive processes observed on a rectangular part of a lattice. An explicit expression for the asymptotic bias of Yule-Walker estimators is obtained. It is shown that this bias disappears if we use the so-called unbiased sample autocovariance function or least squares estimators.

多中心临床试验的二元数据分析AI 解读

We develop several methods for estimating the treatment effect difference defined as the overall log-odds ratio of favourable response in a multicentre clinical trial comparing two treatments with binary response. A simulation study compares the bias and mean squared error of the point estimates and the exact coverage probabilities of confidence intervals obtained distributions.

因果推断所依赖的假设AI 解读

SUMMARY Statisticians commonly make causal inferences from the results of randomized experiments, but usually question causal inferences from observational studies on the grounds that untestable assumptions are required. This paper explains the basis for this situation and examines, within quite a general framework, various assumptions that appear in the literature. It is demonstrated how the role of each assumption is intimately related to the sort of causal inference being…

利用替代失效时间数据提高临床试验的成本效益AI 解读

In clinical trials with failure time, outcomes, the cost of follow-up for the endpoint of primary interest is sometimes expensive. In many of these settings, one or more secondary or surrogate failure time outcomes are also available which either occur much earlier or are much less expensive to follow than the primary outcome. This paper presents a method for using these secondary outcomes to increase the power of detecting a treatment effect on the primary outcome only,…

因果型空间自回归过程估计量的偏差AI 解读

We study the asymptotic distribution of Yule-Walker and least squares estimators for twodimensional causal autoregressive processes observed on a rectangular part of a lattice. An explicit expression for the asymptotic bias of Yule-Walker estimators is obtained. It is shown that this bias disappears if we use the so-called unbiased sample autocovariance function or least squares estimators.

多中心临床试验二元数据的分析AI 解读

We develop several methods for estimating the treatment effect difference defined as the overall log-odds ratio of favourable response in a multicentre clinical trial comparing two treatments with binary response. A simulation study compares the bias and mean squared error of the point estimates and the exact coverage probabilities of confidence intervals obtained distributions.

贝叶斯网络中的参数更新AI 解读

A Bayes network is a directed acyclic graph in which the links are quantified by fixed conditional probabilities and the nodes represent random variables. The primary use of the network is to provide an efficient method for updating conditional probabilities in the graph. We consider the consequences of using the network as the computational device for updating parameter estimates in the dynamic linear model, a discrete time Bayesian model. We show that using the network…