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The impact of imprecisely measured covariates on estimating gene-environment interactions

Greenwood, D.C., Gilthorpe, M.S. and Cade, J.E. (2006) The impact of imprecisely measured covariates on estimating gene-environment interactions. BMC Medical Research Methodology, 6 (21). ISSN 1471-2288


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The effects of measurement error in epidemiological exposures and confounders on estimated effects of exposure are well described, but the effects on estimates for gene-environment interactions has received rather less attention. In particular, the effects of confounder measurement error on gene-environment interactions are unknown.


We investigate these effects using simulated data and illustrate our results with a practical example in nutrition epidemiology.


We show that the interaction regression coefficient is unchanged by confounder measurement error under certain conditions, but biased by exposure measurement error. We also confirm that confounder measurement error can lead to estimated effects of exposure biased either towards or away from the null, depending on the correlation structure, with associated effects on type II errors.


Whilst measurement error in confounders does not lead to bias in interaction coefficients, it may still lead to bias in the estimated effects of exposure. There may still be cost implications for epidemiological studies that need to calibrate all error-prone covariates against a valid reference, in addition to the exposure, to reduce the effects of confounder measurement error

Item Type: Article
Copyright, Publisher and Additional Information: © 2006 Greenwood et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Institution: The University of Leeds
Academic Units: The University of Leeds > Faculty of Medicine and Health (Leeds) > School of Medicine (Leeds) > Leeds Institute of Genetics, Health and Therapeutics (LIGHT) > Division of Epidemiology & Biostatistics (Leeds)
Depositing User: Sherpa Assistant
Date Deposited: 17 Oct 2008 13:34
Last Modified: 20 Jun 2014 10:23
Published Version: http://dx.doi.org/10.1186/1471-2288-6-21
Status: Published
Publisher: Biomed Central Ltd.
Refereed: Yes
Identification Number: 10.1186/1471-2288-6-21
URI: http://eprints.whiterose.ac.uk/id/eprint/4763

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