Trends in the utilization of dental outpatient services affected by the expansion of health care benefits in South Korea to include scaling: a 6-year interrupted time-series study

Interrupted time series analysis of chronic periodontitis-related procedures before and after the scaling reimbursement policy in Korea

AIM

To study the use of a quasi-experimental design to assess the effects of scaling reimbursement policies on the incidence of chronic-periodontitis procedures.

MATERIALS AND METHODS

Interrupted time series analysis was used to compare the effects before and after policy implementation using data on the number of periodontitis-related procedures from the Korean National Health Insurance Service-National Sample Cohort (n = 740,467) and the Health Screening Cohort (n = 337,904). Periodontitis-related procedures with diagnosis codes were categorized into basic (scaling or root planing), intermediate (subgingival curettage) and advanced (tooth extraction, periodontal flap surgery, bone grafting for alveolar bone defects or guided tissue regeneration). Subjects' demographics and comorbidities were considered. The incidence rate of immediate changes and gradual effects before and after policy implementation was assessed.

RESULTS

Following the policy implementation from July 2013, an immediate increase was observed in total and basic procedures. No significant changes were noted in intermediate and advanced procedures initially. A decrease in the slope of intermediate procedures was observed in both databases. Advanced procedures showed varied trends, with no change in the National Sample Cohort but an increase in the Health Screening Cohort, particularly among subjects with comorbidities.

CONCLUSIONS

Following the new policy implementation, the number of intermediate procedures decreased while the number of advanced procedures increased, especially among patients with comorbidities. These findings offer valuable insights on policy evaluation.

Policy interventions to improve the accessibility and affordability of Dutch dental care. A scoping review of effective interventions

Caries and periodontitis remain prevalent in the Netherlands. Given the assumption that increasing the accessibility and affordability of dental care can improve oral health outcomes, policy interventions aimed at improving these aspects may contribute to better oral health. To identify possible solutions, this scoping review firstly identifies policy interventions from around the world that have effectively improved the accessibility or affordability of dental care. Secondly, this review discusses the potential of the policy interventions identified that are applicable to the Dutch healthcare sector specifically. A literature search was performed in four databases. Two reviewers independently screened all potentially relevant titles and abstracts before doing the same for the full texts. Only studies that had quantitatively evaluated the effectiveness of policy interventions aimed at improving the accessibility or affordability of dental care were included. 61 of the 1288 retrieved studies were included. Interventions were grouped into four categories. Capacity interventions (n = 5) mainly focused on task delegation. Coverage interventions (n = 25) involved the expansion of covered dental treatments or the group eligible for coverage. Managed care interventions (n = 20) were frequently implemented in school or community settings. Payment model interventions (n = 11) focused on dental reimbursement rates or capitation. 199 indicators were identified throughout the 61 included studies. Indicators were grouped into three categories: accessibility (n = 137), affordability (n = 21), and oral health status (n = 41). Based on the included studies, increasing managed care interventions for children and adding dental coverage to the basic health insurance plan for adults could improve access to dental care in the Netherlands. Due to possible spillover effects, it is advisable to investigate a combination of these policy interventions. Further research will be necessary for the development of effective policy interventions in practice.

An Investigation of the Association between Health Screening and Dental Scaling in Korea

Dental disease is one of the most prevalent chronic diseases worldwide, and its expenditure is continuously increasing. Periodontal disease is increasing as a chronic non-communicable disease in adults and older people. Health screening has been shown to be cost-effective and improves the quality of life through the early detection of diseases. This study aimed to analyze the relationship between national health screening and dental scaling as a preventive service for periodontal disease. The study used sample cohort data from 2002 to 2015 provided by the National Health Insurance Sharing Service in South Korea. A logistic regression analysis of the utilization of dental scaling was performed to identify the independent effects of national health screening. People who underwent health screening showed a higher tendency to undergo dental scaling. Additionally, disparities in utilization according to socioeconomic status were reduced among those who underwent screening. The intervention to extend dental coverage could be more beneficial when combined with health screening, encouraging more people to participate and reducing inequalities in utilization.

Trends in Self-Rated Poor Oral Health Among all Age Populations in Korea from 2007 to 2015: Monitoring Expansion of Dental Insurance

OBJECTIVES

This study explored trends in self-rated poor oral health (SRPOH) from 2007 to 2015 among all age groups to monitor changes after the expansion of dental insurance.

METHODS

Repeated cross-sectional data from 2007 to 2015 Korea National Health and Nutrition Examination Surveys were collected and analysed. The respondents (n = 20,199) were categorised into four age groups: 0-19, 20-44, 45-64, and ≥65 years. The outcome variable was SRPOH, with independent variables being socioeconomic factors, sex, household income, and education. The age-sex standardised prevalence rate was calculated to determine trends, and complex samples logistic regression analysis was performed to confirm the factors affecting SRPOH.

RESULTS

Self-rated poor oral health prevalence decreased significantly from 2007 to 2009 (25%) to 2013 to 2015 (14%) in the age groups of 0-19 and 20-44 years (P < 0.05), whereas the SRPOH prevalence in the age groups of 45-64 and ≥65 years did not undergo any significant changes. Although the prevalence decreased by 6% among older adults, over 40% older women still experienced SRPOH. A sex gap increased with age but did not change over time. SRPOH was strongly associated with sex, income, and education across all age groups; the association did not notably change from 2007 to 2015.

CONCLUSIONS

Self-rated poor oral health improved among younger people in Korea. The gender gap in the prevalence increased with age and persisted over time. However, income was the strongest determinant of SRPOH among all age groups, regardless of dental insurance expansion. Further studies should aim to draw causal inferences to explore the policy impact of dental insurance benefits.

Has the Health Insurance Coverage of Scaling Contributed Positively to Periodontal Health in Korea?

This study aimed to evaluate the effectiveness of the health insurance coverage of dental scaling (introduced in 2013) using the Community Periodontal Index of Treatment Needs parameter among Korean adults aged 20 years or older. We used the Korea National Health and Nutrition Examination Survey data from before and after 2013 to analyze the statistical significance and associations of the covariates with the prevalence of healthy periodontal tissues, prevalence of people in need of scaling, and prevalence of periodontal diseases. The results showed that the prevalence of healthy periodontal tissues increased by 4.9% (from 34.2% to 39.1%), the number of people in need of scaling decreased by 5% (from 65.9% to 60.9%), and the prevalence of periodontal diseases increased by 7.2% (from 23.4% to 30.6%). Moreover, after the scaling coverage policy, the odds ratio of the prevalence of healthy periodontal tissues was 1.10 times higher, the prevalence of the need for scaling was 1.5 times higher, and the prevalence of periodontal diseases was 0.90 times lower. Therefore, the state should formulate policies that provide dental biofilm management through a disclosing agent, impart education about oral hygiene, and develop a health management system that enables the concurrent management of periodontal diseases and systemic diseases.

Insurance coverage expansion and inequalities in unmet oral healthcare needs in Korea: Repeated cross-sectional analysis, 2007-2015

OBJECTIVES

This study aimed to evaluate whether Korea's 2012 health insurance expansion of adult dental care coverage reduced income-based oral health inequalities.

METHODS

This study analysed nationally representative repeated cross-sectional data from waves IV to VI (2007-2015) of the Korean National Health and Nutrition Examination Survey. The main outcome variable is unmet dental needs due to cost, and the independent variable is household income. Further, the slope index of inequality (SII) and the relative index of inequality (RII) were calculated. Calculations were adjusted for income and stratified by age group, gender and survey period. Data from the three waves were pooled to estimate the SII and RII trend coefficients between survey years. These were tested using two-way interaction terms for each age group and gender.

RESULTS

Some changes in income-based inequality trends were identified. Relative and absolute inequalities in unmet needs (indicated by the RII and SII) decreased over time for most age groups. However, this trend was not observed for older women.

CONCLUSIONS

Income-based inequalities in unmet dental needs persisted among older women in Korea despite the insurance expansion. By contrast, after the 2012 insurance expansion, the absolute and relative inequality in unmet dental needs decreased for young and middle-aged as well as older adults.

Did expanded access to denture services improve chewing ability in the Korean older population? Results of a regression discontinuity analysis

The Korean National Health Insurance expanded the dental insurance in 2012 to cover denture services for older adults. We analyzed whether the new policy improved of chewing ability in the eligible population. We used regression discontinuity (RD), a quasi-experimental design, to analyze the effects of the expanded dental insurance. We analyzed data from the Korea National Health and Nutrition Examination Survey conducted in 2010 and 2015. The study population consisted of two groups: the treatment group, aged 65 and above who were eligible; and the control group, under 65 years of age who were not eligible for the dental insurance benefit. The main outcome evaluated was self-reported chewing difficulty. The RD analysis showed that in 2015, the chewing difficulty in aged above 65 was 2.2% lower than in those aged under 65. However, the difference was not statistically significant (P = 0.76). The results from the falsification testing of predetermined covariates, placebo cut-offs, and bandwidths validated our main conclusion. The expansion of dental insurance benefits to include dentures for the older adults did not improve the chewing ability in the eligible population. Future studies should evaluate long-term outcomes of oral health as well as the social impacts on the elderly.

Estimating Lifetime Dental Care Expenditure in South Korea: An Abridged Life Table Approach

The aim of this study was to measure the magnitude and distribution of a Korean’s lifetime dental expenses depending on age and sex, by constructing a hypothetical lifetime and life table of survival. Additionally, we estimated the difference in life expectancy between men and women and its impact on dental expenses. We used the 2015 Korea Health Panel Survey to calculate the total dental expenditure, including expenses paid directly by patients and those paid by insurers. We generated survival profiles to simulate dental expenses during a typical lifetime (from birth to age 95) using the abridged life table (five-year intervals for age groups) in 2015 from the South Korean Statistical Information Service. We independently calculated the remaining dental expenses for survivors of all ages. The results showed that an estimate of average lifetime dental expenditure was $31,851 per capita: $31,587 for men and $32,318 for women. Nearly 33% of the average per capita lifetime dental expenditure was attributable to the longer life expectancy of women, with no statistically significant difference in lifetime dental expenditure between men and women. Many survivors incurred 70% of their lifetime dental expenses before age 65. The results highlighted the need for policymakers to address spending on age-specific dental care owing to extended life expectancy, given the disproportionate share of healthcare resources supporting the elderly.

Did Expanded Dental Insurance Improve Chewing Ability in the Older Korean Population? Results of an Interrupted Time-series Analysis

Background

In 2012, the Korean National Health Insurance extended its coverage to include denture services for older adults. We examined whether the new policy resulted in improved chewing ability in the eligible population.

Methods

We used interrupted time-series (ITS) analysis, a quasi-experimental design, to analyze the effect of the policy. We used data from the Korea National Health and Nutrition Examination Survey conducted from 2007 to 2016–2018. The study population consisted of two groups: the treatment group, aged 65 years or older and eligible for the dental insurance benefit; and the control group, those younger than 65 years and ineligible. The main evaluated outcome was self-reported chewing difficulty.

Results

The ITS analysis showed that chewing difficulty decreased annually by 0.93% (95% CI, −1.30 to −0.55%) and 0.38% (95% CI, −0.59 to −0.16%) after the policy extension in the older than 65 and younger than 65 groups, respectively. However, we could not conclude that the insurance extension affected chewing difficulty because there was a decrease in the control group as well.

Conclusion

Chewing ability improved in both older and younger adults regardless of dental insurance coverage for older adults. Other exogenous factors probably led to the improvements in chewing ability as well as dental insurance benefits.

Did the Expansion of Insurance Coverage for Oral Health Reduce Self-reported Oral Health Inequalities in Korea? Results of Repeated Cross-Sectional Analysis, 2007-2015

BACKGROUND

In 2009, the South Korean government expanded universal health insurance to include oral health services. In the present study, we sought to examine whether improved access resulted in a reduction in income-based self-reported oral health inequalities.

METHODS

We analyzed repeated cross-sectional data from the Korea National Health and Nutrition Examination Survey (KNHANES) waves IV through VI (2007-2015). We analyzed self-reported oral health status among 68,431 subjects. Changes in oral health inequalities across four income levels (low, middle-low, middle-high, and high) were assessed with the Slope Index of Inequality (SII) and the Relative Index of Inequality (RII).

RESULTS

The average oral health status of children and adolescents improved the most over the observation period. The absolute magnitude of oral health inequalities (measured by the SII) improved for most groups, with the notable exception of young male adults. By contrast, the ratio of poor oral health between high- and low-income groups (measured by the RII) changed little over time, indicating that relative inequalities remained resistant to change.

CONCLUSIONS

The expansion of dental health insurance may not be sufficient to move the needle on self-reported oral health inequalities among adults.