Weighted nearest neighbours-based control group selection method for observational studies.

Although in observational studies, propensity score matching is the most widely used balancing method, it has received much criticism. The main drawback of this method is that the individuals of the case and control groups are paired in the compressed one-dimensional space of propensity scores. In t...

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Main Authors: Szabolcs Szekér, Ágnes Vathy-Fogarassy
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2020-01-01
Series:PLoS ONE
Online Access:https://doi.org/10.1371/journal.pone.0236531
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author Szabolcs Szekér
Ágnes Vathy-Fogarassy
author_facet Szabolcs Szekér
Ágnes Vathy-Fogarassy
author_sort Szabolcs Szekér
collection DOAJ
description Although in observational studies, propensity score matching is the most widely used balancing method, it has received much criticism. The main drawback of this method is that the individuals of the case and control groups are paired in the compressed one-dimensional space of propensity scores. In this paper, such a novel multivariate weighted k-nearest neighbours-based control group selection method is proposed which can eliminate this disadvantage of propensity score matching. The proposed method pairs the elements of the case and control groups in the original vector space of the covariates and the dissimilarities of the individuals are calculated as the weighted distances of the subjects. The weight factors are calculated from a logistic regression model fitted on the status of treatment assignment. The efficiency of the proposed method was evaluated by Monte Carlo simulations on different datasets. Experimental results show that the proposed Weighted Nearest Neighbours Control Group Selection with Error Minimization method is able to select a more balanced control group than the most widely applied greedy form of the propensity score matching method, especially for individuals characterized with few descriptive features.
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spelling doaj.art-5709ab1c62a045f28e5004ba1ceda8b92022-12-21T18:33:35ZengPublic Library of Science (PLoS)PLoS ONE1932-62032020-01-01157e023653110.1371/journal.pone.0236531Weighted nearest neighbours-based control group selection method for observational studies.Szabolcs SzekérÁgnes Vathy-FogarassyAlthough in observational studies, propensity score matching is the most widely used balancing method, it has received much criticism. The main drawback of this method is that the individuals of the case and control groups are paired in the compressed one-dimensional space of propensity scores. In this paper, such a novel multivariate weighted k-nearest neighbours-based control group selection method is proposed which can eliminate this disadvantage of propensity score matching. The proposed method pairs the elements of the case and control groups in the original vector space of the covariates and the dissimilarities of the individuals are calculated as the weighted distances of the subjects. The weight factors are calculated from a logistic regression model fitted on the status of treatment assignment. The efficiency of the proposed method was evaluated by Monte Carlo simulations on different datasets. Experimental results show that the proposed Weighted Nearest Neighbours Control Group Selection with Error Minimization method is able to select a more balanced control group than the most widely applied greedy form of the propensity score matching method, especially for individuals characterized with few descriptive features.https://doi.org/10.1371/journal.pone.0236531
spellingShingle Szabolcs Szekér
Ágnes Vathy-Fogarassy
Weighted nearest neighbours-based control group selection method for observational studies.
PLoS ONE
title Weighted nearest neighbours-based control group selection method for observational studies.
title_full Weighted nearest neighbours-based control group selection method for observational studies.
title_fullStr Weighted nearest neighbours-based control group selection method for observational studies.
title_full_unstemmed Weighted nearest neighbours-based control group selection method for observational studies.
title_short Weighted nearest neighbours-based control group selection method for observational studies.
title_sort weighted nearest neighbours based control group selection method for observational studies
url https://doi.org/10.1371/journal.pone.0236531
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