The effect of conditional dependence on the evaluation of diagnostic tests.

abstract：:Precision medicine seeks to provide treatment only if, when, to whom, and at the dose it is needed. Thus, precision medicine is a vehicle by which healthcare can be made both more effective and efficient. Individualized treatment rules operationalize precision medicine as a map from current patient information to a re...

journal_title：Biometrics

authors： Butler EL,Laber EB,Davis SM,Kosorok MR

更新日期：2018-03-01 00:00:00

abstract：:Many statistical tests have been proposed for case-control data to detect disease association with multiple single nucleotide polymorphisms (SNPs) in linkage disequilibrium. The main reason for the existence of so many tests is that each test aims to detect one or two aspects of many possible distributional difference...

journal_title：Biometrics

authors： Han F,Pan W

更新日期：2012-03-01 00:00:00

abstract：:A considerable body of literature has arisen over the past 15 years for analyzing univariate repeated measures data. However, it is rare in applied biomedical research for interest to be restricted to a single outcome measure. In this paper, we consider the case of bivariate repeated measures. We apply a generalized e...

journal_title：Biometrics

authors： Rochon J

更新日期：1996-06-01 00:00:00

abstract：:Identifying factors associated with increased medical cost is important for many micro- and macro-institutions, including the national economy and public health, insurers and the insured. However, assembling comprehensive national databases that include both the cost and individual-level predictors can prove challengi...

journal_title：Biometrics

authors： Johnson BA,Long Q,Huang Y,Chansky K,Redman M

更新日期：2016-09-01 00:00:00

abstract：:The Colton model for the choice between two medical treatments is studied, with the additional assumption that there is a time lag between the administration of the treatments and the availability of the responses. Two simple procedures are suggested for dealing with patients who arrive during the waiting period, caus...

journal_title：Biometrics

authors： Langenberg P,Srinivasan R

更新日期：1981-03-01 00:00:00

abstract：:Studies using a series of increasing doses of a compound, including a zero dose control, are often conducted to study the effect of the compound on the response of interest. For a one-way design, Tukey et al. (1985, Biometrics 41, 295-301) suggested assessing trend by examining the slopes of regression lines under ari...

journal_title：Biometrics

authors： Quan H,Capizzi T

更新日期：1999-06-01 00:00:00

abstract：:We study the issue of identifiability of mixture models in the context of capture-recapture abundance estimation for closed populations. Such models are used to take account of individual heterogeneity in capture probabilities, but their validity was recently questioned by Link (2003, Biometrics 59, 1123-1130) on the ...

journal_title：Biometrics

authors： Holzmann H,Munk A,Zucchini W

更新日期：2006-09-01 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

authors： Buonaccorsi JP

更新日期：1995-12-01 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

authors： Contreras M,Ryan LM

更新日期：2000-12-01 00:00:00

abstract：:In an effort to determine whether a particular treatment causes a particular outcome event, data are obtained from a database system that records events when they occur, and for such events, the system records exposure to the treatment. That is, the system records information about cases. The system provides no inform...

journal_title：Biometrics

authors： Rosenbaum PR

更新日期：2005-03-01 00:00:00

abstract：:We develop locally D-optimal designs for nonlinear models when the variance of the response is a function of its mean. Using the two-parameter Michaelis-Menten model as an example, we show that the optimal design depends on both the type of heteroscedasticity and the magnitude of the variation. In addition, our result...

journal_title：Biometrics

authors： Dette H,Wong WK

更新日期：1999-09-01 00:00:00

abstract：:We present a class of simple designs that can be used in early dose-finding studies in HIV. Such designs, in contrast with Phase I designs in cancer, have a lot of the Phase II flavor about them. Information on efficacy is obtained during the trial and is as important as that relating to toxicity. The designs proposed...

journal_title：Biometrics

authors： O'Quigley J,Hughes MD,Fenton T

更新日期：2001-12-01 00:00:00

abstract：:Conditional likelihood based on counting processes are combined with a Horvitz-Thompson estimator to yield a population size estimator that is more efficient than the existing ones. Random removals are allowed in the recapturing process. Simulation studies are shown to assess the performance of the proposed estimators...

journal_title：Biometrics

authors： Yip PS,Wang Y

更新日期：2002-03-01 00:00:00

abstract：:We consider a fully model-based approach for the analysis of distance sampling data. Distance sampling has been widely used to estimate abundance (or density) of animals or plants in a spatially explicit study area. There is, however, no readily available method of making statistical inference on the relationships bet...

journal_title：Biometrics

authors： Johnson DS,Laake JL,Ver Hoef JM

更新日期：2010-03-01 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

authors： Royston JP

更新日期：1982-06-01 00:00:00

abstract：:In spatial surveys for estimating the density of objects in a survey region, systematic designs will generally yield lower variance than random designs. However, estimating the systematic variance is well known to be a difficult problem. Existing methods tend to overestimate the variance, so although the variance is g...

journal_title：Biometrics

authors： Fewster RM

更新日期：2011-12-01 00:00:00

abstract：:In multivariate matching, fine balance constrains the marginal distributions of a nominal variable in treated and matched control groups to be identical without constraining who is matched to whom. In this way, a fine balance constraint can balance a nominal variable with many levels while focusing efforts on other mo...

journal_title：Biometrics

authors： Yang D,Small DS,Silber JH,Rosenbaum PR

更新日期：2012-06-01 00:00:00

abstract：:In this article, we develop new methods for estimating average treatment effects in observational studies, in settings with more than two treatment levels, assuming unconfoundedness given pretreatment variables. We emphasize propensity score subclassification and matching methods which have been among the most popular...

journal_title：Biometrics

authors： Yang S,Imbens GW,Cui Z,Faries DE,Kadziola Z

更新日期：2016-12-01 00:00:00

abstract：:This paper considers methods for estimating the relationship between a binary response Y and the genetic effects responsible for a second binary trait Z. The responses Y are observed only for target individuals, and the responses Z are observed only for the relatives of these targets. The analysis consists of two part...

journal_title：Biometrics

authors： Houwing-Duistermaat JJ,van Houwelingen HC,de Winter JP

更新日期：2000-09-01 00:00:00

abstract：:In clinical studies, longitudinal biomarkers are often used to monitor disease progression and failure time. Joint modeling of longitudinal and survival data has certain advantages and has emerged as an effective way to mutually enhance information. Typically, a parametric longitudinal model is assumed to facilitate t...

journal_title：Biometrics

authors： Ding J,Wang JL

更新日期：2008-06-01 00:00:00

abstract：:Markov chain models are frequently used for studying event histories that include transitions between several states. An empirical transition matrix for nonhomogeneous Markov chains has previously been developed, including a detailed statistical theory based on counting processes and martingales. In this article, we s...

journal_title：Biometrics

authors： Aalen OO,Borgan O,Fekjaer H

更新日期：2001-12-01 00:00:00

abstract：:For many long-lived animal species, individuals do not breed every year, and are often not accessible during non-breeding periods. Individuals exhibit site fidelity if they return to the same breeding colony or spawning ground when they breed. If capture and recapture is only possible at the breeding site, temporary e...

journal_title：Biometrics

authors： Pledger S,Baker E,Scribner K

更新日期：2013-12-01 00:00:00

abstract：:Calibration, the statistical consistency of forecast distributions and the observations, is a central requirement for probabilistic predictions. Calibration of continuous forecasts is typically assessed using the probability integral transform histogram. In this article, we propose significance tests based on scoring ...

journal_title：Biometrics

authors： Held L,Rufibach K,Balabdaoui F

更新日期：2010-12-01 00:00:00

abstract：:In this article, we demonstrate a statistical method for fitting the parameters of a sophisticated network and epidemic model to disease data. The pattern of contacts between hosts is described by a class of dyadic independence exponential-family random graph models (ERGMs), whereas the transmission process that runs ...

journal_title：Biometrics

authors： Groendyke C,Welch D,Hunter DR

更新日期：2012-09-01 00:00:00

abstract：:The distribution of health care payments to insurance plans has substantial consequences for social policy. Risk adjustment formulas predict spending in health insurance markets in order to provide fair benefits and health care coverage for all enrollees, regardless of their health status. Unfortunately, current risk ...

journal_title：Biometrics

authors： Zink A,Rose S

更新日期：2020-09-01 00:00:00

abstract：:As ultra high-dimensional longitudinal data are becoming ever more apparent in fields such as public health and bioinformatics, developing flexible methods with a sparse model is of high interest. In this setting, the dimension of the covariates can potentially grow exponentially as ...

journal_title：Biometrics

authors： Green B,Lian H,Yu Y,Zu T

更新日期：2020-08-04 00:00:00

abstract：:Geographic information about the levels of toxics in environmental media is commonly used in regional environmental health studies when direct measurements of personal exposure is limited or unavailable. In this article, we propose a statistical framework for analyzing the spatial distribution of topsoil geochemical p...

journal_title：Biometrics

authors： Calder CA,Craigmile PF,Zhang J

更新日期：2009-03-01 00:00:00

abstract：SUMMARY:Recently, median regression models have received increasing attention. When continuous responses follow a distribution that is quite different from a normal distribution, usual mean regression models may fail to produce efficient estimators whereas median regression models may perform satisfactorily. In this ar...

journal_title：Biometrics

authors： Yi GY,He W

更新日期：2009-06-01 00:00:00

abstract：:A general formula for the frequency of different recombinant gamete types, in terms of the underlying distribution of crossovers, is derived. This formula may be applied to any theoretical model of recombination in which it is assumed that there is no chromatid interference. Multiple-locus recombination data may be ev...

journal_title：Biometrics

authors： Risch N,Lange K

更新日期：1983-12-01 00:00:00

abstract：:In a presentation of various methods for assessing the sensitivity of regression results to unmeasured confounding, Lin, Psaty, and Kronmal (1998, Biometrics54, 948-963) use a conditional independence assumption to derive algebraic relationships between the true exposure effect and the apparent exposure effect in a re...

journal_title：Biometrics

authors： Vanderweele TJ

更新日期：2008-06-01 00:00:00