Multiple imputation of covariates by fully conditional specification: Accommodating the substantive model

Missing covariate data commonly occur in epidemiological and clinical research, and are often dealt with using multiple imputation. Imputation of partially observed covariates is complicated if the substantive model is non-linear (e.g. Cox proportional hazards model), or contains non-linear (e.g. sq...

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Main Authors: Bartlett, Jonathan W, Seaman, Shaun R, White, Ian R, Carpenter, James R
Format: Online
Language:English
Published: SAGE Publications 2015
Online Access:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4513015/
id pubmed-4513015
recordtype oai_dc
spelling pubmed-45130152015-07-31 Multiple imputation of covariates by fully conditional specification: Accommodating the substantive model Bartlett, Jonathan W Seaman, Shaun R White, Ian R Carpenter, James R Articles Missing covariate data commonly occur in epidemiological and clinical research, and are often dealt with using multiple imputation. Imputation of partially observed covariates is complicated if the substantive model is non-linear (e.g. Cox proportional hazards model), or contains non-linear (e.g. squared) or interaction terms, and standard software implementations of multiple imputation may impute covariates from models that are incompatible with such substantive models. We show how imputation by fully conditional specification, a popular approach for performing multiple imputation, can be modified so that covariates are imputed from models which are compatible with the substantive model. We investigate through simulation the performance of this proposal, and compare it with existing approaches. Simulation results suggest our proposal gives consistent estimates for a range of common substantive models, including models which contain non-linear covariate effects or interactions, provided data are missing at random and the assumed imputation models are correctly specified and mutually compatible. Stata software implementing the approach is freely available. SAGE Publications 2015-08 /pmc/articles/PMC4513015/ /pubmed/24525487 http://dx.doi.org/10.1177/0962280214521348 Text en © The Author(s) 2014 http://creativecommons.org/licenses/by/3.0/ This article is distributed under the terms of the Creative Commons Attribution 3.0 License (http://www.creativecommons.org/licenses/by/3.0/) which permits any use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access page (http://www.uk.sagepub.com/aboutus/openaccess.htm).
repository_type Open Access Journal
institution_category Foreign Institution
institution US National Center for Biotechnology Information
building NCBI PubMed
collection Online Access
language English
format Online
author Bartlett, Jonathan W
Seaman, Shaun R
White, Ian R
Carpenter, James R
spellingShingle Bartlett, Jonathan W
Seaman, Shaun R
White, Ian R
Carpenter, James R
Multiple imputation of covariates by fully conditional specification: Accommodating the substantive model
author_facet Bartlett, Jonathan W
Seaman, Shaun R
White, Ian R
Carpenter, James R
author_sort Bartlett, Jonathan W
title Multiple imputation of covariates by fully conditional specification: Accommodating the substantive model
title_short Multiple imputation of covariates by fully conditional specification: Accommodating the substantive model
title_full Multiple imputation of covariates by fully conditional specification: Accommodating the substantive model
title_fullStr Multiple imputation of covariates by fully conditional specification: Accommodating the substantive model
title_full_unstemmed Multiple imputation of covariates by fully conditional specification: Accommodating the substantive model
title_sort multiple imputation of covariates by fully conditional specification: accommodating the substantive model
description Missing covariate data commonly occur in epidemiological and clinical research, and are often dealt with using multiple imputation. Imputation of partially observed covariates is complicated if the substantive model is non-linear (e.g. Cox proportional hazards model), or contains non-linear (e.g. squared) or interaction terms, and standard software implementations of multiple imputation may impute covariates from models that are incompatible with such substantive models. We show how imputation by fully conditional specification, a popular approach for performing multiple imputation, can be modified so that covariates are imputed from models which are compatible with the substantive model. We investigate through simulation the performance of this proposal, and compare it with existing approaches. Simulation results suggest our proposal gives consistent estimates for a range of common substantive models, including models which contain non-linear covariate effects or interactions, provided data are missing at random and the assumed imputation models are correctly specified and mutually compatible. Stata software implementing the approach is freely available.
publisher SAGE Publications
publishDate 2015
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4513015/
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