نتایج جستجو برای: misclassification

تعداد نتایج: 4685  

Journal: :Revista brasileira de epidemiologia = Brazilian journal of epidemiology 2015
Armando Baena Isabel Cristina Garcés-Palacio Hugo Grisales

INTRODUCTION In epidemiological studies, misclassification error, especially differential misclassification, has serious implications. OBJECTIVE To illustrate how differential misclassification error (DME) and non-differential misclassification error (NDME) occur in a case-control design and to describe the trends in DME and NDME. METHODS Different sensitivity levels, specificity levels, pr...

1999
Elham Rahme Lawrence Joseph Theresa W. Gyorkos

We investigate the sample size problem when a binomial parameter is to be estimated, but some degree of misclassification is possible. The problem is especially challenging when the degree to which misclassification occurs is not exactly known. Motivated by a Canadian survey of the prevalence of toxoplasmosis infection in pregnant women, we examine the situation where it is desired that a margi...

2012
Maria Eugénia Ferrão Harvey Goldstein M. E. Ferrão H. Goldstein

Misclassification is found in many of the variables used in social sciences and, in practice, tends to be ignored in statistical analyses, and this can lead to biased results. This paper shows how to correct for differential misclassification in multilevel models and illustrates the extent to which this changes fixed and random parameter estimates. Reliability studies on self-reported behaviour...

2014
Jocelyn Holden Bolin W. Holmes Finch

Statistical classification of phenomena into observed groups is very common in the social and behavioral sciences. Statistical classification methods, however, are affected by the characteristics of the data under study. Statistical classification can be further complicated by initial misclassification of the observed groups. The purpose of this study is to investigate the impact of initial tra...

2003
Arthur Lewbel

This paper provides conditions for identification, and an associated estimator, of the average effect of a binary treatment or policy on a scalar outcome in models where treatment may be misclassified. Misclassification probabilities and the true probability of treatment are also identified. Misclassification occurs when treatment is measured with error, that is, some units are reported to have...

Journal: :Open Journal of Statistics 2021

In this work, we developed a theoretical framework leading to misclassification of the final size epidemic data for stochastic SIR (Susceptible-Infective-Removed), household model, with false negative and positive misclassification probabilities. Maximum likelihood based algorithm is then employed its inference. We then analyzed compared estimates the two dimensional model those three four...

Journal: :Statistics in medicine 2010
Rong Chu Paul Gustafson Nhu Le

Poor measurement of explanatory variables occurs frequently in observational studies. Error-prone observations may lead to biased estimation and loss of power in detecting the impact of explanatory variables on the response. We consider misclassified binary exposure in the context of case-control studies, assuming the availability of validation data to inform the magnitude of the misclassificat...

2015
Wenqi Wu James Stamey David Kahle Igor Burstyn Gheorghe Luta

Count data are subject to considerable sources of what is often referred to as non-sampling error. Errors such as misclassification, measurement error and unmeasured confounding can lead to substantially biased estimators. It is strongly recommended that epidemiologists not only acknowledge these sorts of errors in data, but incorporate sensitivity analyses into part of the total data analysis....

Journal: :Clinical chemistry 2007
Corné Biesheuvel Les Irwig Patrick Bossuyt

Before a new test is introduced in clinical practice, its accuracy should be assessed. In the past decade, researchers have put an increased emphasis on exploring differences in test sensitivity and specificity between patient subgroups. If the reference standard is imperfect and the prevalence of the target condition differs among subgroups, apparent differences in test sensitivity and specifi...

Journal: :International journal of epidemiology 2008
Anne M Jurek Sander Greenland George Maldonado

A well-known heuristic in epidemiology is that non-differential exposure or disease misclassification biases the expected values of an estimator toward the null value. This heuristic works correctly only when additional conditions are met, such as independence of classification errors. We present examples to show that, even when the additional conditions are met, if the misclassification is onl...

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