A step-by-step guide to Propensity Score Matching method using R program in dental research

An,  Hwayoen; Lim,  Hoi-Jeong

J Korean Dent Assoc > Volume 58(3); 2020 > Article

The Journal of The Korean Dental Association 2020;58(3):152-168.
Published online March 31, 2020.

치의학 연구에서 R program을 이용한 성향점수매칭의 단계적 안내

안화연¹, 임회정²

^¹전남대학교 치과병원
^²전남대학교 치의학전문대학원 치과교정학교실, 치의학 연구소

A step-by-step guide to Propensity Score Matching method using R program in dental research

Hwayoen An¹, Hoi-Jeong Lim²

¹Chonnam National University Hospita
²Department of Orthodontics, Chonnam National University, School of Dentistry, Dental Science Research Institute

Abstract

The propensity score matching method is a statistical method used to reduce selection bias in observational studies and to show effects similar to random allocation. There are many observational studies in dentistry research, and differences in baseline covariates between the control and case groups affect the outcome. In order to reduce the bias due to confounding variables, the propensity scores are used by equating groups based on the baseline covariates. This method is effective, especially when there are many covariates or the sample size is small. In this paper, the propensity score matching method was explained in a simple way with a dental example by using R software. This simulated data were obtained from one of retrospective study. The control group and the case group were matched according to the propensity score and compared before and after treatment. The propensity score matching method could be an alternative to compensate for the disadvantage of the observation study by reducing the bias based on the covariates with the propensity score.

Key Words: Propensity Score Matching;matched case-control study;dental research;