Trend in the Incidence of Severe Partial Edentulism among Adults Using the Korean National Health Insurance Service Claim Data, 2014–2018

Purpose@#Missing teeth is one of the most important indicators of oral health behavior and the result of dental caries, periodontal disease, and injuries. This study examined a trend in the incidence of severe partial edentulism (SPE) using the Korean National Health Insurance Service (KNHIS) data. @*Materials and Methods@#Data of adults aged ≥20 years were obtained from the KNHIS for the 2014–2018 period. SPE was defined in dental information within a population with a treatment history of dental scaling as having 1 to 8 natural teeth. Crude incidence rates (CIRs) and age-standardized incidence rates (AIRs) with 95% confidence interval were calculated per 100000 persons. The Cochran Armitage trend (CAT) test and average annual percentage change were used to analyze SPE trends. @*Results@#The CIRs among Korean adults were from 346.29 to 391.11 in 2014–2016 and from 391.11 to 354.09 in 2016–2018. The AIRs trend statistically increased by 4.31% from 346.29 to 376.80 and decreased by 4.72% from 376.80 to 342.10. The AIRs in men increased by 4.00% and decreased by 3.01%. The AIRs in women decreased by 2.18% and increased by 2.11% (CAT; p<0.01). The AIRs by region and income also showed trends of increase and decrease. @*Conclusion@#The study showed that the incidence trend of SPE increased and decreased from 2014 to 2018. This result would be able to aid in the planning of public oral health, and may also serve as fundamental data for verifying the impact of the public oral health policies implemented.

Measurement of oral health related with quality of life using EQ-5D and OHIP-14 / 대한구강보건학회지

OBJECTIVES: Given that oral health is one of the major factors affecting the quality of life, it is necessary to measure the oral-health-related-quality-of-life dimension in order to value health. The aim of this study was to compare the dimensions of oral-health-related quality-of-life measured by a generic health measure [EuroQol-5D (EQ-5D)] and an oral health specific measure [Oral Health Impact Profile 14 (OHIP-14)]. METHODS: A questionnaire including EQ-5D, OHIP-14, self-rated general/oral health, and visual analog scale (VAS) was developed, and both patients and dentists participated in measuring the patient's oral health-related quality of life based on oral diseases. Data was collected from the Dental University Hospital from 2016 to 2017. For descriptive analysis, t-test, chi-square, ANOVA, Tukey HSD post-test, and Pearson correlation analysis were performed. To confirm the factors associated with EQ-5D, multiple regression analysis was conducted. RESULTS: A total of 305 subjects were selected for the final analysis excluding the partially missing questionnaires. EQ-5D and OHIP-14 showed a statistically significant correlation and a sensitive distribution of the values depending on the oral diseases. The values of EQ-5D and OHIP-14 ranged from highest to lowest in the following order of oral diseases: endodontic, TMJ, gingivitis, and tooth sensitivity. A 10-point increase in OHIP-14 was associated with a 0.34-point increase in EQ-5D. CONCLUSIONS: The result of this study proved to be consequential since both OHIP-14 and EQ-5D were good measures for oral health-related quality of life, and the oral disease status could also be measured in terms of health valuation weights. This increased the possibility of comparison with general health, and provided the loss of socioeconomic costs of individuals, families, and societies due to oral diseases.

Comparison of EQ-5D and OHIP-14 sub-dimensions for measuring oral health-related quality of life / 대한구강보건학회지

OBJECTIVES: Oral-specific measures are often preferred for examining oral disease outcomes; however, generic measures can add additional important information. This study measured oral health-related quality of life, reflecting the multidimensional characteristics of oral health, and we compared sub-dimensions of the Oral Health Impact Profile 14 (OHIP-14) with the EuroQual-5D (EQ-5D). METHODS: Data from 305 patients were collected from patients who visited the dental university hospital in 2016-2017 and included EQ-5D, OHIP-14, and self-rated general/oral health questionnaires. A factor analysis was performed to identify sub-dimensions of the EQ-5D and OHIP-14, and a cluster analysis was conducted to examine the degree of overlap among the sub-dimensions of two measures. RESULTS: In the factor analysis, a range of OHIP-14 items (physical pain, physical disability, and handicap) loaded on factor 3, along with EQ-5D items. In the analysis of groups with relatively low oral qualities of life, moving from the bottom towards the top of the dendrogram, the next major branch split was the dimension of EQ-5D pain/discomfort, anxiety/depression items, which clustered between the OHIP-14 interrupted meal and difficult relaxing subscales. CONCLUSIONS: The results of this study suggest that using the EQ-5D for oral health status expends the complementary role of oral health-related quality of life measures.

Effectiveness of oral examination for infants and toddlers: effects on subsequent utilization and costs / 대한구강보건학회지

OBJECTIVES: With increasing emphasis being placed on early interventions for health promotion, early dental visits to prevent early childhood caries have been receiving more attention. Infant oral health examinations have been implemented as a component of early health examination in South Korea, but there is a lack of research on its effectiveness. This study aimed to estimate the effectiveness of infant and toddler oral health examinations by performing economic analyses of infant health examinations and dental treatment costs after examinations. METHODS: The analyses were conducted using the National Health Insurance Service claims data. Subjects included in this study were children who had undergone their “3(rd) infant oral health examination (54-65 months)” between 2010 and 2014. To estimate dental treatment costs over the five years, four retrospective cohorts were evaluated, which included a total of 256,965 subjects. The direct medical costs following infant oral health examinations were calculated over five years (including only costs from health insurance claims), and the effects of infant oral health examinations were compared. RESULTS: Although the rate of infant oral health examinations showed a persistently increasing trend, differences were observed according to the type of health insurance. Children who underwent infant oral health examinations showed a higher number of visits to the dentist, but lower dental treatment costs compared with children who did not undergo examinations. CONCLUSIONS: This study confirmed, from an economic perspective, the effects of policy interventions that emphasize the necessity of early intervention and a life-course health management strategy, based on the concept that oral health is not determined at specific time points, but rather is determined by the accumulation of exposure to various factors over the course of life.

Survival of individual teeth after non-surgical endodontic treatment / 대한구강보건학회지

OBJECTIVES: The present study aimed to estimate the survival rate of teeth after non-surgical root canal treatment and to investigate the effect of income on the tooth survival rate. METHODS: The study included 1,414.668 endodontically treated teeth from 1,193.666 persons enrolled in the National Health Insurance Service in 2002. A survival analysis of the teeth was performed using the Kaplan-Meier method. The survival rates were calculated using a follow-up period of 11 years after the root canal treatment. RESULTS: In the present study, the 11-year cumulative survival rate of teeth after non-surgical endodontic treatments was 86.90%. The survival rates of teeth tended to decrease for the posterior teeth; the maxillary teeth showed a lower survival rate than that of the mandibular teeth. The teeth with the highest survival rates were the mandibular left lateral incisor, maxillary right incisor, mandibular right lateral incisor, and maxillary left central incisor, in that order. The lowest survival rates were shown by the mandibular second molar, maxillary second molar, maxillary first molar, and mandibular first molar, in that order. The survival rate of the first molar (#16, #26, #36, #46) was higher in the low-income group than in the high-income group (P<0.001). CONCLUSIONS: This study represents the outcome pattern of root canal treatment among South Korean individuals. These study findings can be used as comparative data for clinical decision making about endodontic treatment.

Effects of Periodontal Disease on Cardio-Cerebrovascular Disease: A Focus on Personal Income and Social Deprivation / 치위생과학회지

The study aimed to investigate the effects of differences between personal income and social deprivation on the association between cardio-cerebrovascular disease (hypertension, stroke) and periodontal disease. This study used 12 years of cohort data from the Korea National Health Insurance Service covering the years 2002 to 2013. Among the patients aged more than 40 years who had received treatment for periodontal disease 224,067 and 284,730 who had not received treatment for hypertension and stroke, respectively, were included in the analysis. The Kaplan-Meier analysis revealed differences in the rate of treatment for cardio-cerebrovascular disease (hypertension, stroke) according to regional differences, the rate of treatment increased as the composite deprivation index value increased. The difference in treatment rates for cardio- cerebrovascular disease (hypertension, stroke) according to income was found to be higher in the treatment group with low income. This study empirically proved that the association between systemic disease and periodontal disease varies depending on personal income and the regional socioeconomic deprivation level. This shows that the clinical influence of periodontal illness on systemic disease differs according to the personal socio-demographic characteristic and residential area and that an individual's characteristic (income and the regional) needs to be considered along with the patient's clinical intervention in the disease treatment process.

Horizontal inequities in dental service utilization / 대한구강보건학회지

OBJECTIVES: Health inequity across social classes is closely associated with unequal healthcare utilization, and there have been sustained efforts to improve healthcare accessibility. Public healthcare insurance is one attempt to eliminate such health inequities. The purpose of this study was to examine a horizontal equity index for dental service utilization, which included diverse factors affecting health inequity, such as personal health and social context variables. METHODS: The 2008 to 2011 outpatient datasets of the Korean Healthcare Panel were analyzed. Zero-inflated negative binomial regression (ZINB) was conducted to estimate need-adjusted healthcare use with the following independent variables: health outcome (EQ-5D), chronic disease, and the Composite Deprivation Index. The concentration index and horizontal inequality index were calculated for the actual use of dental services and resource use-based dental visits. RESULTS: The ZINB regression analysis showed that age and personal health level on the EQ-5D were significant predictors, and the Composite Deprivation Index was influential. The concentration index for dental service utilization indicated that there was inequity favoring high-income brackets, but there was inequity favoring low-income groups when health level was taken into account. Overall, the horizontal equity index for dental service utilization estimated based on the two values was positive, meaning that there was inequity favoring high-income groups. CONCLUSIONS: The use of dental services has been steadily on the rise, and dental service accessibility and public healthcare coverage seem to have expanded. However, when the horizontal equity index for dental service utilization was estimated based on health level, there was inequity, with high-income groups making more use of dental services. Thus, equal access to dental services is not guaranteed, despite the adjustment for need. Methods of increasing dental service use in different income brackets must be carefully considered to remove disparities in the use of dental services.

The effect of economic factors on private health insurance enrollment and dental care utilization / 대한구강보건학회지

OBJECTIVES: The study aimed to examine and derive policy implications from the contribution of private health insurance towards the effectiveness and equity of dental care utilization. METHODS: The study used 2010-2011 Korea Health Panel data. We applied a two-stage probit least square (2SPLS) analysis method to 10,577 people who were aged 20 years and over and had out-patient health care utilization. Under the assumption that high demanders for dental outpatient health services try to subscribe and hold private health insurance, the study focuses on the changes in income and private health insurance status. RESULTS: The results of the descriptive statistics indicated that the number of employed enrolled in private health insurance increased as age decreased and income increased. Two-year consecutive non-enrollment of private health insurance was highest in the groups aged 65 years or above, those that had completed primary school or below, and those that belonged to the top income bracket. The highest rates of continued enrollment in private health insurance were observed in the top fifth income group (highest quintile) and those with a college degree. Income was observed to have an effect on private health insurance enrollment status and the frequency of dental care services used. The results of the analysis indicated that changes in private health insurance status did not affect the frequency of dental care services used, but the frequency of dental care services used had a significantly positive effect on continued enrollment in private health insurance. CONCLUSIONS: To secure the right of health for citizens, it is necessary to establish measures that emphasize equity and strengthen benefit coverage of health insurance. Moreover, regulatory policies that support the low-income population are required.

Dental hospital selection factors using triangle fuzzy numbers with a focus on supplier factors / 대한구강보건학회지

OBJECTIVES: This study analyzes supplier factors that affect the selection of dental hospitals. METHODS: This study performed an analysis by combining outpatient use data, household data, and additional survey data in 2011 from the Korea Health Panel Annual Data from 2008 to 2011. Standardization was conducted on variables of supplier-related factors, and a four-point scale survey questionnaire was converted into a triangle fuzzy number to fuzzify the data. A two-part model was applied to the fuzzified values. In the first part, a study was conducted to determine which supplier factors affected the decision to visit dental outpatient facilities. In the second part, dental outpatient facilities use was analyzed based on the supplier factors. RESULTS: The study results showed that ages, marital status, education level, position of employment, and income level affected the decision to visit dental outpatient facilities. Furthermore, gender and age affected the usage of dental outpatient facilities. In conclusion, supplier factors affected the decision to visit dental outpatient facilities and usage significantly. Among the supplier factors, dentist recommendation was a significant factor. CONCLUSIONS: Based on the study results, it is necessary for dental care suppliers to provide a measure for appropriate service strategy focused on dental consumers' demand on improvements of dental service value and dental care quality.

Dental care utilization patterns by the status of ADL and IADL in the elderly / 대한구강보건학회지

OBJECTIVES: This study sought to analyze the effects of ADL and IADL on dental care utilization behaviors for the elderly 65 years of age and older. METHODS: Using data from the Korea Health Panel 2010-2011, we examined 2683 elderly people who did not use dental care and 12,550 cases of dental care utilization of 963 elderly people who used dental care among people aged 65 and older who responded to the items of ADL and IADL limitations. We employed two-part model (TPM) including logistic regression analysis in a first part of the model and negative binomial regression analysis in a second part of the model to estimate dental care utilization patterns associated with ADL and IADL of elderly adults. RESULTS: A frequency analysis revealed that dental care utilization was more frequent in the elderly with IADL limitations than in the elderly with ADL limitations. The first part of TPM predicted that dental care utilization was more likely to be present in males and younger age group along with increasing number of chronic diseases and independence in ADL and IADL. The results of the second part of TPM estimated the quantity of dental care utilization increased among high income groups. CONCLUSIONS: Limitations in ADL and IADL were found to affect the decision to seek dental care utilization, but physical limitations to have no statistical effect on the quantity of dental care utilization, once dental care utilization was taken for treatment. These findings suggested that dental care utilization would be determined by supplier induced demand and patient's own power to obtain treatment. Since decision to take dental care utilization, despite the barriers of limitations in activities, is an important factor which can satisfy medical needs, various policies to reflect oral health and physical fitness are required.

Drug prescription rates in dental health services / 대한구강보건학회지

OBJECTIVES: This study examined the misuse and abuse of antibiotics in relation to the demographic and socioeconomic characteristics of patients given prescriptions by dental providers. METHODS: We examined data collected in 2011 by the Korea Health Panel from 3,836 dental visits. The data included multiple visits per individual for 3,738 household members of 2,588 households using outpatient dental services. The data were analyzed by dental service provider type, using four types of beta-regression. Model analysis and comparison were performed using Akaike's information criterion (AIC) and Bayesian information criterion (BIC) to select the best model. RESULTS: Prescription rates according to type of dental service provider are as follows: 18% by dental hospitals and 19%-20% by dental clinics. The patient factors contributing to the prescription rate are gender, age, education, and income level. Higher antibiotics exposure was found in patients who were male, older, with less education, and lower incomes. Patient exposure to antibiotics did not significantly differ between dental hospitals and dental clinics. CONCLUSIONS: When prescribing antibiotics in dental practices, patient safety can be improved by reducing misuse and abuse of antibiotics through consideration of individual patient characteristics.

How does private health insurance affect dental care utilization? / 대한구강보건학회지

OBJECTIVES: This study discussed dental care utilization efficiency and equity from the perspective of private health insurance policy using the 2011 Korea Health Panel dataset. METHODS: A total of 10,577 subjects, aged 20 years or older, were selected from a larger sample (N=18,256). The study conducted a two-part model analysis to determine the impact of private health insurance on utilization and amount of dental care. RESULTS: Average monthly payment of private health insurance is 76,727 KRW. Analysis of average monthly fees and income distribution by quartile showed that higher income groups pay proportionally more for private health insurance. The highest income group was 3.82 times more likely to have private health insurance than the lowest income group. Those with private health insurance coverage had a higher probability of using dental care but were not more likely to use a greater number of dental services. CONCLUSIONS: Based on these empirical findings, a guarantee of health care system and policy equity and efficiency should be established for changes in private health insurance.

Trends of household income and dental care spending / 대한구강보건학회지

OBJECTIVES: This empirical study aimed to identify the differences in expenditures by household income level, as well as the patterns of dental care spending by dental services. METHODS: We analyzed the Korea Health Panel's data collected between 2008 and 2010. We calculated expenditures by service items by itemizing dental care services such as conservative, prosthetic, orthodontic, periodontal, surgical, preventive, dental implant care. Then we obtained the ratios of spending per item and per visit to overall out-of-pocket spending on dental care and used these as the weights for dental care cost allocation. Income quintiles were derived using the equivalence scale. Kakwani's concentration index was used to determine the degree of disparity by income quintile, and 95% confidence intervals were computed. RESULTS: Out-of-pocket expenditures on dental care steadily increased over time and income quintile. The analysis of dental care spending by income quintile revealed that the level of expenditure of the first income quintile was 3.6 times lower than that of the fifth income quintile. In terms of expenditure comparison between 2008 and 2010, the first quintile households showed an increased spending on prosthetic and periodontal treatments, whereas the fifth quintile households spent a relatively high proportion on orthodontic and dental implant care. The concentration index revealed that conservative services and root canal treatments was significant and positive, indicating that the demand for, and utilization of, these services increase as household income increases. In contrast, prosthetic services showed a significant negative trend, indicating that these services are not as common among those with higher incomes. CONCLUSIONS: To address the problems associated with the disparity in dental care expenditures based on income levels, it is necessary to establish policies that expand health insurance coverage and provide other supportive measures for low-income populations.

Socioeconomic Costs of Food-Borne Disease Using the Cost-of-Illness Model: Applying the QALY Method / 예방의학회지

OBJECTIVES: This study estimated the annual socioeconomic costs of food-borne disease in 2008 from a societal perspective and using a cost-of-illness method. METHODS: Our model employed a comprehensive set of diagnostic disease codes to define food-borne diseases with using the Korea National Health Insurance (KNHI) reimbursement data. This study classified the food borne illness as three types of symptoms according to the severity of the illness: mild, moderate, severe. In addition to the traditional method of assessing the cost-of-illness, the study included measures to account for the lost quality of life. We estimated the cost of the lost quality of life using quality-adjusted life years and a visual analog scale. The direct cost included medical and medication costs, and the non-medical costs included transportation costs, caregiver's cost and administration costs. The lost productivity costs included lost workdays due to illness and lost earnings due to premature death. RESULTS: The study found the estimated annual socioeconomic costs of food-borne disease in 2008 were 954.9 billion won (735.3 billion won-996.9 billion won). The medical cost was 73.4 - 76.8% of the cost, the lost productivity cost was 22.6% and the cost of the lost quality of life was 26.0%. CONCLUSIONS: Most of the cost-of-illness studies are known to have underestimated the actual socioeconomic costs of the subjects, and these studies excluded many important social costs, such as the value of pain, suffering and functional disability. The study addressed the uncertainty related to estimating the socioeconomic costs of food-borne disease as well as the updated cost estimates. Our estimates could contribute to develop and evaluate policies for food-borne disease.

Development of Composite Deprivation Index for Korea: The Correlation with Standardized Mortality Ratio / 예방의학회지

OBJECTIVES: The aims of this paper were to develop the composite deprivation index (CDI) for the sub-district (Eup-Myen-Dong) levels based on the theory of social exclusion and to explore the relationship between the CDI and the standardized mortality ratio (SMR). METHODS: The paper calculated the age adjusted SMR and we included five dimensions of social exclusion for CDI; unemployment, poverty, housing, labor and social network. The proxy variables of the five dimensions were the proportion of unemployed males, the percent of recipients receiving National Basic Livelihood Security Act benefits, the proportion of households under the minimum housing standard, the proportion of people with a low social class and the proportion of single-parent household. All the variables were standardized using geometric transformation and then we summed up them for a single index. The paper utilized the 2004-2006 National Death Registry data, the 2003-2006 national residents' registration data, the 2005 Population Census data and the 2005-2006 means-tested benefit recipients' data. RESULTS: The figures were 115.6, 105.8 and 105.1 for the CDI of metropolitan areas (big cities), middle size cities and rural areas, respectively. The distributional variation of the CDI was the highest in metropolitan areas (8.9 - 353.7) and the lowest was in the rural areas (26.8 - 209.7). The extent and relative differences of deprivation increased with urbanization. Compared to the Townsend and Carstairs index, the CDI better represented the characteristics of rural deprivation. The correlation with the SMR was statistically significant and the direction of the CDI effects on the SMR was in accordance with that of the previous studies. CONCLUSIONS: The study findings indicated mortality inequalities due to the difference in the CDI. Despite the attempt to improve deprivation measures, further research is warranted for the consensus development of a deprivation index.

Health Inequality Measurement in Korea Using EuroQol-5 Dimension Valuation Weights / 예방의학회지

OBJECTIVES: Despite various government initiatives, including the expansion of national health insurance coverage, health inequality has been a key health policy issue in South Korea during the past decade. This study describes and compares the extent of the total health inequality and the income-related health inequality over time among Korean adults. METHODS: This study employs the 1998, 2001 and 2005 Korean National Health and Nutrition Examination Surveys (KNHANESs). The self-assessed health (SAH) ordinal responses, measured on a five-point scale, rescaled to cardinal values to measure the health inequalities with using interval regression. The boundaries of each threshold for the interval regression analysis were obtained from the empirical distribution of the EuroQol-5 Dimension (EQ-5D) valuation weights estimated from the 2005 KNHANES. The final model predicting the individuals' health status included age, gender, educational attainment, occupation, income, and the regional prosperity index. The concentration index was used to measure and analyze the health inequality. RESULTS: The KNHANES data showed an unequal distribution of the total health inequality in favor of the higher income groups, and this is getting worse over time (0.0327 in 1998, 0.0393 in 2001 and 0.0924 in 2005). The income-related health inequality in 2005 was 0.0278, indicating that 30.1% of the total health inequality can be attributed to income. CONCLUSIONS: The findings indicate there are health inequalities across the sociodemographic and income groups despite the recent government's efforts. Further research is warranted to investigate what potential policy actions are necessary to decrease the health inequality in Korea.