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复杂抽样下的两样本秩检验AI 解读

Rank tests are widely used for exploratory and formal inference in the health and social sciences. With the widespread use of data from complex survey samples in medical and social research, there is increasing demand for versions of rank tests that account for the sampling design. We propose a general approach to constructing design-based rank tests when comparing groups within a complex sample and when using a national survey as a reference distribution, and illustrate…

多阶段病例对照研究的有效估计AI 解读

In this paper we discuss the analysis of multi-phase, or multi-stage, case-control studies and present an efficient semiparametric maximum-likelihood approach that unifies and extends earlier work, including the seminal case-control paper by Prentice & Pyke (1979), work by Breslow & Cain (1988), Scott & Wild (1991), Breslow & Holubkov (1997) and others. The theoretical derivations apply to arbitrary binary regression models but we present results for logistic regression and…

病例增补样本下的二元回归模型拟合AI 解读

In a case-augmented study, measurements on a random sample from a population are augmented by information from an independent sample of cases, that is units with some characteristic of interest. We show that inferences about the effect of the covariates on the probability of being a case can be made by fitting a modified prospective likelihood. We also show that this procedure is fully efficient.

用均值估计方程分析簇大小不可忽略的簇相关数据AI 解读

Most methods for analysing cluster-correlated biological data implicitly assume the ignorability of cluster sizes. When this assumption fails, the resulting inferences may be asymptotically invalid. Hoffman et al. (2001) proposed a simple but computationally intensive method, based on a large number of within-cluster resamples and associated separate estimating equations, that leads to asymptotically valid inferences whether the cluster sizes are ignorable or not. We study a…

病例对照研究中的假设检验AI 解读

Prentice & Pyke (1979) have shown that valid estimators of the odds-ratio parameters in a logistic regression model may be obtained from case-control data by fitting the model as if the data had been obtained in a prospective study. The resulting estimates of standard errors are also valid asymptotically. We extend the Prentice-Pyke result to likelihood ratio tests obtained from fitting a prospective model. These tests are asymptotically exact if the hypothesis involves only…

病例对照研究中的假设检验AI 解读

SUMMARY Prentice & Pyke (1979) have shown that valid estimators of the odds-ratio parameters in a logistic regression model may be obtained from case-control data by fitting the model as if the data had been obtained in a prospective study. The resulting estimates of standard errors are also valid asymptotically. We extend the Prentice-Pyke result to likelihood ratio tests obtained from fitting a prospective model. These tests are asymptotically exact if the hypothesis…

For testing the goodness-of-fit of a $\log$-linear model to a multi-way contingency table with cell proportions estimated from survey data, Rao and Scott (1984) derived a first-order correction, $\delta\ldot$, to Pearson chi-square statistic, $X^2$ (or the likelihood ratio statistic, $G^2$) that takes account of the survey design. It was also shown that $\delta\ldot$ requires the knowledge of only the cell design effects (deffs) and the marginal deffs provided the model…

病例—对照或选择依赖抽样下的 Logistic 模型拟合AI 解读

SUMMARY There has been a great deal of interest in recent years in fitting logistic and log-linear models to tables of population counts estimated from survey data. Since maximum likelihood methods are not available in general for complex survey designs, most work has concentrated on adapting standard methods developed for multinomial sampling. Maximum likelihood methods have been developed for some special designs, however, and we might expect ad hoc methods to be less…

调查数据估计单元比例时多维列联表的卡方检验AI 解读

The impact of survey design on standard multinomial-based methods for a multiway contingency table is studied, under nested loglinear models. The asymptotic null distribution of the Pearson chi-squared test statistic, $X^2$ (or the likelihood ratio test statistic, $G^2$) is obtained as a weighted sum of independent $\chi^2_1$ random variables, and the weights are then related to the familiar design effects (deffs) used by survey samplers. A simple correction to $X^2$ (or $G^2$…

两阶段抽样对普通最小二乘方法的影响AI 解读

We look at the effect of intracluster correlation on standard procedures in linear regression. The ordinary least squares estimator, , of the coefficient vector performs well in most cases but the usual estimator of cov() and procedures based on this such as confidence intervals and hypothesis tests can be seriously misleading. The size of the effect, however, tends to be smaller than the corresponding effect on the variance of an estimated mean in two-stage sampling…

复杂抽样分类数据分析：拟合优度与二维表独立性的卡方检验AI 解读

The effect of stratification and clustering on the asymptotic distributions of standard Pearson chi-squared test statistics for goodness of fit (simple hypothesis) and independence in a two-way contingency table, denoted as X 2 and XI 2, respectively, is investigated. It is shown that both X 2 and XI 2 are asymptotically distributed as weighted sums of independent χ1 2 random variables. The weights are then related to the familiar design effects (deffs) used by survey…

有限总体抽样与稳健估计AI 解读

The work of Royall and Herson (1973a, 1973b), ensuring the robustness of the standard ratio estimator against polynomial superpopulation models by choosing balanced samples, is extended to a more general regression estimator. The requirement for robustness is then a relationship between the moments of the sample units and those of the remainder of the population which may be achieved approximately by unequal probability sampling.

贝叶斯回归中的缺失变量（二）AI 解读

We are concerned with the problem of parameter estimation in normal regression when some of the observations are missing. A Bayesian approach with vague prior distributions is taken. No assumption is made about the independent variables for which no observations are missing, but the missing components are assumed to be normally distributed with a mean that can depend on the other variables. Joint estimators of the parameters are obtained as the joint mode of the posterior…

贝叶斯回归中的缺失变量（二）AI 解读

We are concerned with the problem of parameter estimation in normal regression when some of the observations are missing. A Bayesian approach with vague prior distributions is taken. No assumption is made about the independent variables for which no observations are missing, but the missing components are assumed to be normally distributed with a mean that can depend on the other variables. Joint estimators of the parameters are obtained as the joint mode of the posterior…

抽样调查中的极小极大设计AI 解读

Blackwell & Girshick (1954) have shown that simple random sampling is the minimax sampling strategy when the quantity being estimated and the space of possible population values are suitably eymmetric. In this paper, sampling with probabilities proportional to size is shown to be the minimax strategy under fairly strong conditions when the quantity being estimated is not symmetric.

抽样调查的极小极大设计AI 解读

Blackwell & Girshick (1954) have shown that simple random sampling is the minimax sampling strategy when the quantity being estimated and the space of possible population values are suitably eymmetric. In this paper, sampling with probabilities proportional to size is shown to be the minimax strategy under fairly strong conditions when the quantity being estimated is not symmetric.

利用时间序列方法分析重复调查AI 解读

Standard time series methods are applied to the analysis of repeated surveys under the assumption that the population parameters at each time period follow a stochastic model. Both overlapping and nonoverlapping surveys are considered in general terms, and specific results are obtained for the time series models assumed in the work of Patterson [10].