Abstract:
:A procedure is given for estimating the ratio of the means of two populations using the data from two independent random samples when the observations are normally distributed with population variances that are related to the population means.
journal_name
Biometricsjournal_title
Biometricsauthors
Cox CPsubject
Has Abstractpub_date
1985-03-01 00:00:00pages
261-5issue
1eissn
0006-341Xissn
1541-0420journal_volume
41pub_type
杂志文章相关文献
BIOMETRICS文献大全abstract::Consider two independent random variables X and Y. The functional R = Pr(X less than Y) [or gamma = Pr(X less than Y) - Pr(Y less than X)] is of practical importance in many situations, including clinical trials, genetics, and reliability. In this paper several approaches to estimation of gamma when X and Y are presen...
journal_title:Biometrics
pub_type: 杂志文章
doi:
更新日期:1986-12-01 00:00:00
abstract::Receiver operating characteristic (ROC) curves are frequently used to assess the usefulness of diagnostic markers. When several diagnostic markers are available, they can be combined by a best linear combination: that is, when the area under the ROC curve of this combination is maximized among all possible linear comb...
journal_title:Biometrics
pub_type: 杂志文章
doi:
更新日期:1997-06-01 00:00:00
abstract::The focus of this article is on the nature of the likelihood associated with N-mixture models for repeated count data. It is shown that the infinite sum embedded in the likelihood associated with the Poisson mixing distribution can be expressed in terms of a hypergeometric function and, thence, in closed form. The res...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/biom.12521
更新日期:2016-12-01 00:00:00
abstract::A transformed Bernstein polynomial that is centered at standard parametric families, such as Weibull or log-logistic, is proposed for use in the accelerated hazards model. This class provides a convenient way towards creating a Bayesian nonparametric prior for smooth densities, blending the merits of parametric and no...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/biom.12104
更新日期:2014-03-01 00:00:00
abstract::In this article, we present an estimation approach for solving nonlinear constrained generalized estimating equations that can be implemented using object-oriented software for nonlinear programming, such as nlminb in Splus or fmincon and lsqnonlin in Matlab. We show how standard estimating equation theory includes th...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/j.0006-341x.2000.01268.x
更新日期:2000-12-01 00:00:00
abstract::We develop a parameterization of the beta-binomial mixture that provides sensible inferences about the size of a closed population when probabilities of capture or detection vary among individuals. Three classes of mixture models (beta-binomial, logistic-normal, and latent-class) are fitted to recaptures of snowshoe h...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/1541-0420.00042
更新日期:2003-06-01 00:00:00
abstract::Dilution assays to determine solute concentration have found wide use in biomedical research. Many dilution assays return imprecise concentration estimates because they are only done to orders of magnitude. Previous statistical work has focused on how to design efficient experiments that can return more precise estima...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/biom.13032
更新日期:2019-09-01 00:00:00
abstract::Often with data from immunoassays, the concentration-response relationship is nonlinear and intra-assay response variance is heterogeneous. Estimation of the standard curve is usually based on a nonlinear heteroscedastic regression model for concentration-response, where variance is modeled as a function of mean respo...
journal_title:Biometrics
pub_type: 杂志文章
doi:
更新日期:1996-03-01 00:00:00
abstract::This paper presents a comparison of three methods of parameter estimation in analysis of linkage between a quantitative trait locus (QTL) and a marker locus: maximum likelihood, mean square for trait cumulative distribution function, and method of moments, employing simulated backcross data. The sensitivity of estimat...
journal_title:Biometrics
pub_type: 杂志文章
doi:
更新日期:1996-06-01 00:00:00
abstract::Asbestos exposure is a well-known risk factor for various lung diseases, and when they occur, workmen's compensation boards need to make decisions concerning the probability the cause is work related. In the absence of a definitive work history, measures of short and long asbestos fibers as well as counts of asbestos ...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/j.1541-0420.2009.01279.x
更新日期:2010-06-01 00:00:00
abstract::The risks of conception, due to sexual intercourse at various times before and after the periovulatory rise in the woman's basal body temperature, are evaluated. In general, the risk is small nine or more days before, and two or more days after, the first day of elevated temperature. The model for the conception proba...
journal_title:Biometrics
pub_type: 杂志文章
doi:
更新日期:1982-06-01 00:00:00
abstract::Large amounts of longitudinal health records are now available for dynamic monitoring of the underlying processes governing the observations. However, the health status progression across time is not typically observed directly: records are observed only when a subject interacts with the system, yielding irregular and...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/biom.13261
更新日期:2020-03-11 00:00:00
abstract::Suppose that the response variable in a well-executed clinical or observational study to evaluate a treatment is the time to a certain event, and a set of baseline covariates or predictors was collected for each study patient. Furthermore, suppose that a significant number of study patients had nontrivial, long-term a...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/j.0006-341x.2003.00116.x
更新日期:2003-12-01 00:00:00
abstract::Multilist capture-recapture methods are commonly used to estimate the size of elusive populations. In many situations, lists are stratified by distinguishing features, such as age or sex. Stratification has often been used to reduce biases caused by heterogeneity in the probability of list membership among members of ...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/j.1541-0420.2007.00767.x
更新日期:2007-09-01 00:00:00
abstract::We consider the problem of testing for a dose-related effect based on a candidate set of (typically nonlinear) dose-response models using likelihood-ratio tests. For the considered models this reduces to assessing whether the slope parameter in these nonlinear regression models is zero or not. A technical problem is t...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/biom.12563
更新日期:2017-03-01 00:00:00
abstract::We estimate how the effect of antiretroviral treatment depends on the time from HIV-infection to initiation of treatment, using observational data. A major challenge in making inferences from such observational data arises from biases associated with the nonrandom assignment of treatment, for example bias induced by d...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/j.1541-0420.2011.01738.x
更新日期:2012-09-01 00:00:00
abstract::Motivated by the particular problem of predicting defoliation based on a measure of gypsy moth egg mass density, prediction in the presence of measurement error is discussed. The measurement error variances and covariances are allowed to vary from unit to unit and are estimated by some type of within unit sampling. A ...
journal_title:Biometrics
pub_type: 杂志文章
doi:
更新日期:1995-12-01 00:00:00
abstract::The use of summary rates of reporting health data is discussed. Directly and indirectly adjusted rates are compared under two models of no interaction. A method of analysis is described whereby a model is first fitted to data in order to investigate assumptions, and subsequently the smoothed rates based on the model a...
journal_title:Biometrics
pub_type: 杂志文章
doi:
更新日期:1980-06-01 00:00:00
abstract::Power and sample-size formulas for testing the homogeneity of relative risks using the score method are presented. The homogeneity score test (Gart, 1985, Biometrika 72, 673-677) is formally equivalent to the Pearson chi-square test, although they look different. Results of this paper may be useful in assessing the va...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/j.0006-341x.1999.00289.x
更新日期:1999-03-01 00:00:00
abstract::Consider a collection of spatially clustered objects where the clusters are geographically rare. Of interest is estimation of the total number of objects on the site from a sample of plots of equal size. Under these spatial conditions, adaptive cluster sampling of plots is generally useful in improving efficiency in e...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/j.0006-341x.2000.00503.x
更新日期:2000-06-01 00:00:00
abstract::In this article, we describe a Bayesian approach to the calibration of a stochastic computer model of chemical kinetics. As with many applications in the biological sciences, the data available to calibrate the model come from different sources. Furthermore, these data appear to provide somewhat conflicting informatio...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/j.1541-0420.2009.01245.x
更新日期:2010-03-01 00:00:00
abstract::In studying rates of occurrence and progression of lesions (or tumors), it is typically not possible to obtain exact onset times for each lesion. Instead, data consist of the number of lesions that reach a detectable size between screening examinations, along with measures of the size/severity of individual lesions at...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/j.0006-341X.2004.00217.x
更新日期:2004-09-01 00:00:00
abstract::Gene-disease association studies based on case-control designs may often be used to identify candidate polymorphisms (markers) conferring disease risk. If a large number of markers are studied, genotyping all markers on all samples is inefficient in resource utilization. Here, we propose an alternative two-stage metho...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/j.0006-341X.2004.00207.x
更新日期:2004-09-01 00:00:00
abstract::With the internet, a massive amount of information on species abundance can be collected by citizen science programs. However, these data are often difficult to use directly in statistical inference, as their collection is generally opportunistic, and the distribution of the sampling effort is often not known. In this...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/biom.12431
更新日期:2016-06-01 00:00:00
abstract::The objective of this paper is to develop statistical methods for estimating current and future numbers of individuals in different stages of the natural history of the human immunodeficiency (AIDS) virus infection and to evaluate the impact of therapeutic advances on these numbers. The approach is to extend the metho...
journal_title:Biometrics
pub_type: 杂志文章
doi:
更新日期:1990-12-01 00:00:00
abstract::Analysis of longitudinal studies is often complicated through differences amongst individuals in the number and spacing of observations. Laird and Ware (1982, Biometrics 38, 963-974) proposed a linear random-effects model to deal with this problem. We propose a generalisation of this model to accommodate multiple rand...
journal_title:Biometrics
pub_type: 杂志文章
doi:
更新日期:1993-06-01 00:00:00
abstract::Objective measures of oxygen consumption and carbon dioxide production by mammals are used to predict their energy expenditure. Since energy expenditure is not directly observable, it can be viewed as a latent construct with multiple physical indirect measures such as respiratory quotient, volumetric oxygen consumptio...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/biom.12706
更新日期:2018-03-01 00:00:00
abstract::When the observed data are contaminated with errors, the standard two-sample testing approaches that ignore measurement errors may produce misleading results, including a higher type-I error rate than the nominal level. To tackle this inconsistency, a nonparametric test is proposed for testing equality of two distribu...
journal_title:Biometrics
pub_type: 杂志文章
doi:10.1111/biom.13207
更新日期:2020-09-01 00:00:00
abstract::Pocock et al. (2012, European Heart Journal 33, 176-182) proposed a win ratio approach to analyzing composite endpoints comprised of outcomes with different clinical priorities. In this article, we establish a statistical framework for this approach. We derive the null hypothesis and propose a closed-form variance est...
journal_title:Biometrics
pub_type: 杂志文章,随机对照试验
doi:10.1111/biom.12225
更新日期:2015-03-01 00:00:00
abstract::The estimation of maternal genetic variances by a multivariate maximum likelihood method is discussed. As an illustration the method is applied to data on Tribolium using a model based on partitioning the maternal genetic effect into additive and dominance components. An alternative model due to Falconer (1965) is als...
journal_title:Biometrics
pub_type: 杂志文章
doi:
更新日期:1976-12-01 00:00:00