Bias attenuation results for dichotomization of a continuous confounder

It is well-known that dichotomization can cause bias and loss of efficiency in estimation. One can easily construct examples where adjusting for a dichotomized confounder causes bias in causal estimation. There are additional examples in the literature where adjusting for a dichotomized confounder c...

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Main Authors: Gabriel Erin E., Peña Jose M., Sjölander Arvid
Format: Article
Language:English
Published: De Gruyter 2022-12-01
Series:Journal of Causal Inference
Subjects:
Online Access:https://doi.org/10.1515/jci-2022-0047
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author Gabriel Erin E.
Peña Jose M.
Sjölander Arvid
author_facet Gabriel Erin E.
Peña Jose M.
Sjölander Arvid
author_sort Gabriel Erin E.
collection DOAJ
description It is well-known that dichotomization can cause bias and loss of efficiency in estimation. One can easily construct examples where adjusting for a dichotomized confounder causes bias in causal estimation. There are additional examples in the literature where adjusting for a dichotomized confounder can be more biased than not adjusting at all. The message is clear, do not dichotomize. What is unclear is if there are scenarios where adjusting for the dichotomized confounder always leads to lower bias than not adjusting. We propose several sets of conditions that characterize scenarios where one should always adjust for the dichotomized confounder to reduce bias. We then highlight scenarios where the decision to adjust should be made more cautiously. To our knowledge, this is the first formal presentation of conditions that give information about when one should and potentially should not adjust for a dichotomized confounder.
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spelling doaj.art-584d289c30f24f0788c8976752e942b92023-02-05T08:27:16ZengDe GruyterJournal of Causal Inference2193-36852022-12-0110151552610.1515/jci-2022-0047Bias attenuation results for dichotomization of a continuous confounderGabriel Erin E.0Peña Jose M.1Sjölander Arvid2Department of Public Health, Section of Biostatistics, University of Copenhagen, Copenhagen, DenmarkDepartment of Computer and Information Science, Linköping University, Linköping, SwedenDepartment of Medical Epidemiology and Biostatistics, Karolinska Institutet, Solna, SwedenIt is well-known that dichotomization can cause bias and loss of efficiency in estimation. One can easily construct examples where adjusting for a dichotomized confounder causes bias in causal estimation. There are additional examples in the literature where adjusting for a dichotomized confounder can be more biased than not adjusting at all. The message is clear, do not dichotomize. What is unclear is if there are scenarios where adjusting for the dichotomized confounder always leads to lower bias than not adjusting. We propose several sets of conditions that characterize scenarios where one should always adjust for the dichotomized confounder to reduce bias. We then highlight scenarios where the decision to adjust should be made more cautiously. To our knowledge, this is the first formal presentation of conditions that give information about when one should and potentially should not adjust for a dichotomized confounder.https://doi.org/10.1515/jci-2022-0047biascausal inferencedichotomized confounder62d20
spellingShingle Gabriel Erin E.
Peña Jose M.
Sjölander Arvid
Bias attenuation results for dichotomization of a continuous confounder
Journal of Causal Inference
bias
causal inference
dichotomized confounder
62d20
title Bias attenuation results for dichotomization of a continuous confounder
title_full Bias attenuation results for dichotomization of a continuous confounder
title_fullStr Bias attenuation results for dichotomization of a continuous confounder
title_full_unstemmed Bias attenuation results for dichotomization of a continuous confounder
title_short Bias attenuation results for dichotomization of a continuous confounder
title_sort bias attenuation results for dichotomization of a continuous confounder
topic bias
causal inference
dichotomized confounder
62d20
url https://doi.org/10.1515/jci-2022-0047
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AT sjolanderarvid biasattenuationresultsfordichotomizationofacontinuousconfounder