Abstract:
:In Part I we presented a covariance structure model for analysing measurement error in the assessment of nitrogen intake. In this paper we include data on urine nitrogen excretion which allows a critical assessment of the model proposed. Inclusion of urine nitrogen data produces more pessimistic estimates of the quality of dietary intake measurements and shows that previous assumptions about independence of measurement error were wrong. This underscores the need for well founded assumptions in the analysis of measurement error.
journal_name
Stat Medjournal_title
Statistics in medicineauthors
Plummer M,Clayton Ddoi
10.1002/sim.4780121005subject
Has Abstractpub_date
1993-05-30 00:00:00pages
937-48issue
10eissn
0277-6715issn
1097-0258journal_volume
12pub_type
杂志文章abstract::In biomedical studies and clinical trials, repeated measures are often subject to some upper and/or lower limits of detection. Hence, the responses are either left or right censored. A complication arises when more than one series of responses is repeatedly collected on each subject at irregular intervals over a perio...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.8017
更新日期:2019-03-15 00:00:00
abstract::Technologic advances give rise to new tests for detecting disease in many fields, including cancer and sexually transmitted disease. Before a new disease screening test is approved for public use, its accuracy should be shown to be better than or at least not inferior to an existing test. Standards do not yet exist fo...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.1058
更新日期:2002-03-30 00:00:00
abstract::Patient reported outcome and observer evaluative studies in clinical trials and post-hoc analyses often use instruments that measure responses on ordinal-rating or Likert scales. We propose a flexible distributional approach by modeling the change scores from the baseline to the end of the study using independent beta...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4012
更新日期:2010-10-30 00:00:00
abstract::Meta-analysis has generally been accepted as a fundamental tool for combining effect estimates from several studies. For binary studies with rare events, the Peto odds ratio (POR) method has become the relative effect estimator of choice. However, the POR leads to biased estimates for the OR when treatment effects are...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6301
更新日期:2014-12-10 00:00:00
abstract::Case-control studies are prone to low power for testing gene-environment interactions (GXE) given the need for a sufficient number of individuals on each strata of disease, gene, and environment. We propose a new study design to increase power by strategically pooling biospecimens. Pooling biospecimens allows us to in...
journal_title:Statistics in medicine
pub_type: 杂志文章
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更新日期:2012-11-20 00:00:00
abstract::This paper develops methods of analysis for active extension clinical trials. Under this design, patients are randomized to treatment or placebo for a period of time (period 1), and then all patients receive treatment for an additional period of time (period 2). We assume a continuous outcome is measured at baseline a...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.2720
更新日期:2007-05-30 00:00:00
abstract::When estimating the probability of natural conception from observational data on couples with an unfulfilled child wish, the start of assisted reproductive therapy (ART) is a competing event that cannot be assumed to be independent of natural conception. In clinical practice, interest lies in the probability of natura...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6280
更新日期:2014-11-20 00:00:00
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journal_title:Statistics in medicine
pub_type: 杂志文章
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journal_title:Statistics in medicine
pub_type: 临床试验,杂志文章,随机对照试验
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更新日期:1999-06-15 00:00:00
abstract::A new, intuitive method has recently been proposed to explore treatment-covariate interactions in survival data arising from two treatment arms of a clinical trial. The method is based on constructing overlapping subpopulations of patients with respect to one (or more) covariates of interest and in observing the patte...
journal_title:Statistics in medicine
pub_type: 杂志文章
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journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4017
更新日期:2010-11-10 00:00:00
abstract::Methods for addressing multiplicity in clinical trials have attracted much attention during the past 20 years. They include the investigation of new classes of multiple test procedures, such as fixed sequence, fallback and gatekeeping procedures. More recently, sequentially rejective graphical test procedures have bee...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.5711
更新日期:2013-05-10 00:00:00
abstract::Biostatistical concepts and methods apply to various problems arising in actual U.S. legal cases. These involve: measures of association, assessing the potential effect of omitted variables and the Peters-Belson approach to regression. In particular, we present the inapplicability of Fisher's exact test in the case wh...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780141505
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journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.7675
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abstract::Hospital length of stay (LOS) is an important measure of healthcare utilization and is generally positively skewed and heterogeneous. We fit a Coxian phase-type distribution to LOS and identify the hidden states of the underlying latent homogeneous Markov model. We demonstrate that selecting an appropriate number of p...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4490
更新日期:2012-06-30 00:00:00
abstract::In a variety of biomedical applications, particularly those involving screening for infectious diseases, testing individuals (e.g. blood/urine samples, etc.) in pools has become a standard method of data collection. This experimental design, known as group testing (or pooled testing), can provide a large reduction in ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3678
更新日期:2009-10-15 00:00:00
abstract::Group sequential testing procedures have been proposed as an approach to conserving resources in biomarker validation studies. Previously, we derived the asymptotic properties of the sequential empirical positive predictive value (PPV) and negative predictive value (NPV) curves, which summarize the predictive accuracy...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6790
更新日期:2016-04-15 00:00:00
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journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.2607
更新日期:2007-03-30 00:00:00
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journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6766
更新日期:2016-03-30 00:00:00
abstract::In many epidemiological studies it is common to resort to regression models relating incidence of a disease and its risk factors. The main goal of this paper is to consider inference on such models with error-prone observations and variances of the measurement errors changing across observations. We suppose that the o...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3343
更新日期:2008-11-10 00:00:00
abstract::Graphical methods based on the analysis of differences between log cumulative hazard functions are considered for a two-group semi-proportional hazard model which allows for interaction between treatments and covariates. Confidence procedures and test statistics that can be used to test for interaction and for main ef...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780111105
更新日期:1992-08-01 00:00:00
abstract::The microbiome plays an important role in human health by mediating the path from environmental exposures to health outcomes. The relative abundances of the high-dimensional microbiome data have an unit-sum restriction, rendering standard statistical methods in the Euclidean space invalid. To address this problem, we ...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.8808
更新日期:2021-02-20 00:00:00
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journal_title:Statistics in medicine
pub_type: 杂志文章
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更新日期:1996-04-15 00:00:00
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journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.1138
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journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.5689
更新日期:2013-06-15 00:00:00
abstract::Observational studies provide a rich source of information for assessing effectiveness of treatment interventions in many situations where it is not ethical or practical to perform randomized controlled trials. However, such studies are prone to bias from hidden (unmeasured) confounding. A promising approach to identi...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.7051
更新日期:2016-12-10 00:00:00
abstract::Multivariate outcomes measured longitudinally over time are common in medicine, public health, psychology and sociology. The typical (saturated) longitudinal multivariate regression model has a separate set of regression coefficients for each outcome. However, multivariate outcomes are often quite similar and many out...
journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.3589
更新日期:2009-06-15 00:00:00
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journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.6584
更新日期:2015-12-20 00:00:00
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journal_title:Statistics in medicine
pub_type: 杂志文章
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更新日期:1999-01-15 00:00:00
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journal_title:Statistics in medicine
pub_type: 杂志文章
doi:10.1002/sim.4780070410
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