Did Dental Insurance Expansion Improve Dental Care Needs Among Korean Adults? Difference in Difference Analysis

Background: In 2012, the Korean government expanded dental insurance for the elderly to promote improved access to dental care. We examined the causal effect of this policy on dental care needs, focusing on low-income older adults. Methods: We compared data before and after policy implementation usi...

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Main Authors: Nam-Hee Kim, Hawazin W. Elani, Ichiro Kawachi
Format: Article
Language:English
Published: Japan Epidemiological Association 2023-02-01
Series:Journal of Epidemiology
Subjects:
Online Access:https://www.jstage.jst.go.jp/article/jea/33/2/33_JE20200596/_pdf
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author Nam-Hee Kim
Hawazin W. Elani
Ichiro Kawachi
author_facet Nam-Hee Kim
Hawazin W. Elani
Ichiro Kawachi
author_sort Nam-Hee Kim
collection DOAJ
description Background: In 2012, the Korean government expanded dental insurance for the elderly to promote improved access to dental care. We examined the causal effect of this policy on dental care needs, focusing on low-income older adults. Methods: We compared data before and after policy implementation using double difference (DD) and triple difference (DDD) analyses. We used the nationally representative data from the Korea National Health and Nutrition Examination Survey from 2010 and 2016–2018. Individuals aged ≥65 years were included in the treatment group, and individuals aged <65 years were included in the control group. Results: Dental insurance expansion was associated with a paradoxical increase in perceived unmet dental needs among elderly individuals (8.8 percentage points increase, 95% CI: 4.7 to 13.0). However, there were improvements in dental prosthetics outcomes (denture wearing [4.0 percentage points, 95% CI: 0.2 to 7.9] and dental implants [5.0 percentage points, 95% CI: 2.1 to 7.9]; P < 0.01). Upon analyzing low-income elderly individuals using DDD analysis, we found that the insurance expansion led to a 21.6% smaller increase in unmet dental needs among low-income adults, compared to high-income adults (95% CI, −35.0 to −8.5; P < 0.01). Conclusion: Dental insurance expansion in South Korea resulted in improvements in access to dental prosthetic services overall. It also led to a smaller increase in unmet dental needs among low-income older adults, compared to high-income adults.
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spelling doaj.art-39df1c0428d842bc858e1984e8852e9d2023-02-06T08:41:56ZengJapan Epidemiological AssociationJournal of Epidemiology0917-50401349-90922023-02-0133210110810.2188/jea.JE20200596Did Dental Insurance Expansion Improve Dental Care Needs Among Korean Adults? Difference in Difference AnalysisNam-Hee Kim0Hawazin W. Elani1Ichiro Kawachi2Department of Dental Hygiene, Wonju College of Medicine, Yonsei University, Wonju, Republic of KoreaDepartment of Oral Health Policy and Epidemiology, Harvard School of Dental Medicine, Boston, MA, USADepartment of Social and Behavioral Sciences, Harvard T.H. Chan School of Public Health, Boston, MA, USABackground: In 2012, the Korean government expanded dental insurance for the elderly to promote improved access to dental care. We examined the causal effect of this policy on dental care needs, focusing on low-income older adults. Methods: We compared data before and after policy implementation using double difference (DD) and triple difference (DDD) analyses. We used the nationally representative data from the Korea National Health and Nutrition Examination Survey from 2010 and 2016–2018. Individuals aged ≥65 years were included in the treatment group, and individuals aged <65 years were included in the control group. Results: Dental insurance expansion was associated with a paradoxical increase in perceived unmet dental needs among elderly individuals (8.8 percentage points increase, 95% CI: 4.7 to 13.0). However, there were improvements in dental prosthetics outcomes (denture wearing [4.0 percentage points, 95% CI: 0.2 to 7.9] and dental implants [5.0 percentage points, 95% CI: 2.1 to 7.9]; P < 0.01). Upon analyzing low-income elderly individuals using DDD analysis, we found that the insurance expansion led to a 21.6% smaller increase in unmet dental needs among low-income adults, compared to high-income adults (95% CI, −35.0 to −8.5; P < 0.01). Conclusion: Dental insurance expansion in South Korea resulted in improvements in access to dental prosthetic services overall. It also led to a smaller increase in unmet dental needs among low-income older adults, compared to high-income adults.https://www.jstage.jst.go.jp/article/jea/33/2/33_JE20200596/_pdfinsuranceunmet dental needsolder adultsdenturesdifference-in-differencetriple-differencequasi-experimental
spellingShingle Nam-Hee Kim
Hawazin W. Elani
Ichiro Kawachi
Did Dental Insurance Expansion Improve Dental Care Needs Among Korean Adults? Difference in Difference Analysis
Journal of Epidemiology
insurance
unmet dental needs
older adults
dentures
difference-in-difference
triple-difference
quasi-experimental
title Did Dental Insurance Expansion Improve Dental Care Needs Among Korean Adults? Difference in Difference Analysis
title_full Did Dental Insurance Expansion Improve Dental Care Needs Among Korean Adults? Difference in Difference Analysis
title_fullStr Did Dental Insurance Expansion Improve Dental Care Needs Among Korean Adults? Difference in Difference Analysis
title_full_unstemmed Did Dental Insurance Expansion Improve Dental Care Needs Among Korean Adults? Difference in Difference Analysis
title_short Did Dental Insurance Expansion Improve Dental Care Needs Among Korean Adults? Difference in Difference Analysis
title_sort did dental insurance expansion improve dental care needs among korean adults difference in difference analysis
topic insurance
unmet dental needs
older adults
dentures
difference-in-difference
triple-difference
quasi-experimental
url https://www.jstage.jst.go.jp/article/jea/33/2/33_JE20200596/_pdf
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AT ichirokawachi diddentalinsuranceexpansionimprovedentalcareneedsamongkoreanadultsdifferenceindifferenceanalysis