Wider Dental Care Coverage Associated with Lower Oral Health Inequalities: A Comparison Study between Japan and England

Change in Geographic Accessibility to Dental Clinics Affects Access to Care

Access to dental clinics is a feature of the neighborhood service environment that may influence oral health care utilization. However, residential selection poses a challenge to causal inference. By studying the involuntary relocation of survivors of the 2011 Great East Japan Earthquake and Tsunami (GEJE), we examined the association between changes in geographic distance to dental clinics and dental visits. Longitudinal data from a cohort of older residents in Iwanuma City directly impacted by the GEJE were analyzed in this study. The baseline survey was conducted in 2010, 7 mo before the occurrence of GEJE, and a follow-up was conducted in 2016. Using Poisson regression models, we estimated the incidence rate ratios (IRR) and 95% confidence intervals (CIs) for the uptake of denture use (as a proxy for dental visits) according to changes in distance from the nearest dental clinic to their house. Age at baseline, housing damage by the disaster, deteriorating economic conditions, and worsened physical activity were used as confounders. Among the 1,098 participants who had not worn dentures before the GEJE, 495 were men (45.1%), with a mean ± SD age at baseline of 74.0 ± 6.9 y. During the 6-year follow-up, 372 (33.9%) participants initiated denture use. Compared to those who experienced a large increase in distance to dental clinics (>370.0-6,299.1 m), a large decrease in distance to dental clinics (>429.0-5,382.6 m) was associated with a marginally significantly higher initiation of denture use among disaster survivors (IRR = 1.28; 95% CI, 0.99-1.66). The experience of major housing damage was independently associated with higher initiation of denture use (IRR = 1.77; 95% CI, 1.47-2.14). Improved geographic access to dental clinics may increase dental visits of disaster survivors. Further studies in non-disaster-affected areas are needed to generalize these findings.

Indicators of integrating oral health care within universal health coverage and general health care in low-, middle-, and high-income countries: a scoping review

BACKGROUND

The World Health Organization (WHO) has recently devoted special attention to oral health and oral health care recommending the latter becoming part of universal health coverage (UHC) so as to reduce oral health inequalities across the globe. In this context, as countries consider acting on this recommendation, it is essential to develop a monitoring framework to measure the progress of integrating oral health/health care into UHC. This study aimed to identify existing measures in the literature that could be used to indicate oral health/health care integration within UHC across a range of low-, middle- and high-income countries.

METHODS

A scoping review was conducted by searching MEDLINE via Ovid, CINAHL, and Ovid Global Health databases. There were no quality or publication date restrictions in the search strategy. An initial search by an academic librarian was followed by the independent reviewing of all identified articles by two authors for inclusion or exclusion based on the relevance of the work in the articles to the review topic. The included articles were all published in English. Articles concerning which the reviewers disagreed on inclusion or exclusion were reviewed by a third author, and subsequent discussion resulted in agreement on which articles were to be included and excluded. The included articles were reviewed to identify relevant indicators and the results were descriptively mapped using a simple frequency count of the indicators.

RESULTS

The 83 included articles included work from a wide range of 32 countries and were published between 1995 and 2021. The review identified 54 indicators divided into 15 categories. The most frequently reported indicators were in the following categories: dental service utilization, oral health status, cost/service/population coverage, finances, health facility access, and workforce and human resources. This study was limited by the databases searched and the use of English-language publications only.

CONCLUSIONS

This scoping review identified 54 indicators in a wide range of 15 categories of indicators that have the potential to be used to evaluate the integration of oral health/health care into UHC across a wide range of countries.

Education-related inequalities in oral health among older adults: Comparing Singapore and Japan

OBJECTIVES

Oral health inequalities exist worldwide, and cross-country comparisons can provide valuable insights into country-level characteristics contributing to such inequalities. However, comparative studies in Asian countries are limited. This study examined the magnitude of education-related oral health inequalities in older adults in Singapore and Japan.

METHODS

Longitudinal data for older adults, aged ≥65 years, from the Panel on Health and Ageing of Singaporean Elderly (PHASE; 2009, 2011-2012, and 2015) and Japan Gerontological Evaluation Study (JAGES; 2010, 2013, and 2016) were used. Dependent variables were being edentate and having a minimal functional dentition (MFD; i.e. ≥20 teeth). The absolute and relative inequalities were calculated using the slope index of inequality (SII) and relative index of inequality (RII) for educational level [low (<6 years); middle (6-12 years); high (>12 years)] in each country.

RESULTS

A total of 1032 PHASE participants and 35 717 JAGES participants were included. At baseline among PHASE participants, 35.9% were edentate and 24.4% had MFD, while among JAGES participants, 8.5% were edentate and 42.4% had MFD. The prevalence of low, middle and high educational levels for PHASE was 76.5%, 18.0% and 5.5%, and for JAGES were 0.9%, 78.1% and 19.7%, respectively. Older adults in Japan had lower education-related inequalities for being edentate [for both SII (-0.53, 95% CI = -0.55 to -0.50) and RII (0.40, 95% CI = 0.33-0.48)] and for not having MFD for both SII (-0.24, 95% CI = -0.27 to -0.20) and RII (0.83, 95% CI = 0.79-0.87) compared to Singapore.

CONCLUSIONS

Education-related inequalities for being edentate and not having MFD were higher among older adults in Singapore compared to Japan.

Difference of income inequalities of denture use by co-payment rates: A JAGES cross-sectional study

OBJECTIVES

Studies suggest that wearing dentures to restore missing teeth can have a positive impact on health status. However, income inequalities in denture wearing exist. The aim of this study was to investigate how differing co-payment rates under the current Japanese Universal Health Insurance Coverage System affect income inequalities in denture non-use among older adults with severe tooth loss.

METHODS

This cross-sectional study used data from the 2019 Japan Gerontological Evaluation Study (JAGES). Self-administered questionnaires were mailed to 345 356 independent people who did not receive long-term care insurance benefits and were aged ≥65 years. The dependent variable was denture non-use, and the independent variable was the equivalent annual household income. The Slope Index of Inequality (SII) and Relative Index of Inequality (RII) were used with regression-based approaches to determine both absolute and relative inequalities in denture non-use by co-payment rates. The covariates were sex, age, years of education, number of teeth and comorbidities.

RESULTS

Of the 240 889 responses received (response rate =69.9%), we analysed 21 594 participants who fulfilled the inclusion criteria. The mean age was 72.8 years (standard deviation =4.1), and 57.6% were men. For 30 per cent, 20 per cent and 10 per cent co-payment rates, the percentages of people who did not use dentures and had severe tooth loss (≤9 teeth) were 18.3%, 13.3%, and 8.5%, respectively. All analyses confirmed significant inequalities in denture non-use. The lower the co-payment rate, the smaller the inequalities. SIIs for each co-payment rate were as follows: 30 per cent =13.35% (95% confidence interval [CI] = 9.61-17.09); 20 per cent =7.85% (95% CI = 4.88-10.81); and 10 per cent =4.85% (95% CI = 2.55-7.16). Inclusion of interaction term between income and co-payment rate significantly lowered the inequalities by co-payment rate in logistic regression analysis and SII. For RII, although the interaction was not statistically significant, a similar trend was observed.

CONCLUSIONS

Income inequalities in denture use existed among older adults with severe tooth loss in Japan, and the inequalities appeared to be greater when the co-payment rate was higher.

Are Public Oral Care Services Evenly Distributed?-Nation-Wide Assessment of the Provision of Oral Care in Japan Using the National Database of Health Insurance Claims

The provision of oral health care services is one of the global challenges under the realization of universal health coverage in many countries. Despite the increasing importance of oral health care in an aging society, the disparities in the provision of oral care in Japan have not been clarified. Therefore, this study investigated the status of oral and dental care provision using the National Database of Health Insurance Claims and Specific Health Checkups (NDB) at the level of prefectures and secondary medical care areas. Additionally, a multiple regression model was applied to identify the influence of human resources in oral care services and economic factors on the standardized claims data ratio (SCR) of total dental receipts. The results showed that the total amount of oral care provided tended to be higher in metropolitan areas, with bimodal peaks in children aged 5-9 and adults in their 70s. The SCR for dental caries showed little difference nationally, but SCR for periodontal disease tended to be higher in prefectures including metropolitan areas. In a multiple regression model, the number of dentists and prefectural income per capita influenced the SCR of total dental receipts. In secondary medical care areas, some depopulated areas are supplemented by adjacent areas. These results suggest that oral health care services in the national health insurance system are generally well provided; however, they are likely to be influenced by human resources and economic disparities, and regional differences may occur in the care of periodontal diseases.

Immediately loaded single-implant mandibular overdentures compared to conventional complete dentures: A cost-effectiveness analysis

BACKGROUND

In recent years, the single-implant mandibular overdenture (SIMO) has been proposed as an alternative to more complex overdenture designs as a simplified implant intervention for edentulous patients.

OBJECTIVE

The aim of this study was to run a cost-effectiveness analysis alongside a randomized clinical trial comparing the SIMO and the conventional complete denture (CCD) treatment. Imediately loaded external hexagon implant and ball attachment were used for the overdenture goup. Direct costs related to therapies were identified and valuated throughout a 1-year period after delivery, in Brazilian currency (R$) and converted into international dollars (I$) using purchase power parity exchange rates. Treatment effectiveness was measured using the OHIP-Edent and satisfaction scores for calculation of incremental cost-effectiveness ratios (ICER).

RESULTS

Outcomes were assessed at the 1-year follow-up for 65 patients (CCD=34; SIMO=31). Overall OHIP-Edent and satisfaction scores improved significantly in the SIMO group, while remained unchanged in the CCD group. The mean overall costs were R$1,179.04 (I$590.99) for the CCD group and R$2,127.91 (I$1,068.20) for the SIMO group - 80.7% incremental cost for SIMO. The ICER calculation for SIMO treatment showed a mean cost of I$48.20 for 1-point reduction in OHIP-Edent scores, and I$12.56 for 1-point increase in satisfaction score.

CONCLUSIONS

Findings support the effectiveness of this simplified and low-cost implant intervention for edentulous patients. SIMO also seems a cost-effective alternative to the CCD and the relatively low incremental cost may potentially increase the utilization of dental implants among older subjects, especially those with limited financial resources.

CLINICAL SIGNIFICANCE

The immediately loaded single-implant mandibular overdenture was superior to the conventional complete denture in terms of patient-reported outcome measures at a low incremental cost.

Examining the associations between oral health and social isolation: A cross-national comparative study between Japan and England

In Western countries, the most important part of the face in communication is the mouth, whereas it is the eyes in Asian countries; thus oral health could be more important in social interactions in Western countries. Our aim was to examine differences in the association between oral health status and social isolation among older people by comparing Japan and England. We used cross-sectional information obtained from adults aged 65+ in two ongoing prospective cohort studies: The Japan Gerontological Evaluation Study (JAGES, N = 120,195) and the English Longitudinal Study of Ageing (ELSA, N = 3,958). The dependent variable, social isolation score (SIS) was calculated from five factors (marital status, social support from children, social support from family, social support from friends, and social participation). The independent variables were self-reported number of remaining teeth (0, 1-9, 10-19, ≥20) and denture use (≥20 teeth, 10-19 teeth with denture, 10-19 teeth without denture, 0-9 teeth with denture, 0-9 teeth without denture), while the covariates in the model were: sex, age, educational attainment, self-rated health, number of comorbidities, household annual equivalized income, mental health status, daily living activities, and smoking status. We examined associations between oral health status and SIS by applying an ordered logit model by country. Compared to England, more Japanese participants were socially isolated (1.4% vs. 5.8%), but fewer were edentulous (13.1% vs. 7.7%). In both countries, poorer oral health further increased the odds of being socially isolated. Pooled analysis of the ordered logit model with an interaction term showed that the association of number of remaining teeth with SIS was stronger in edentulous participants and in England (odds ratio = 1.50, 95% Confidence interval:1.26-1.80). In both countries, oral health was associated with social isolation; this association could be stronger in England than in Japan.

Association of Health Literacy with the Implementation of Exercise during the Declaration of COVID-19 State of Emergency among Japanese Community-Dwelling Old-Old Adults

Health literacy is important for promoting and maintaining good health in old-old adults. It may influence the implementation of exercise in the coronavirus disease epidemic. The present cross-sectional study investigated the association of each dimension of health literacy with the implementation of exercise during the declaration of a state of emergency due to coronavirus disease in community-dwelling old-old adults. We collected data from 483 community-dwelling old-old adults (52.8% women) aged between 77 and 99 years who participated in a mail survey. Participants were divided into exercise or nonexercise groups based on the implementation of exercise during the declaration of a state of emergency. Health literacy was assessed using a 14-item health literacy scale. There were 327 (67.7%) participants in the exercise group and 156 (32.3%) in the nonexercise group. A significantly higher score of health literacy was observed in the exercise group than in the nonexercise group (communicative health literacy score = 14.0 ± 3.6 vs. 12.7 ± 3.8, p = 0.001). In a multivariate logistic regression model adjusted for potential confounders, high communicative health literacy scores were significantly associated with the implementation of exercise during the declaration of a state of emergency (odds ratio = 1.88, 95% confidence interval = 1.20–2.93). Approximately two-thirds of community-dwelling old-old adults implement exercise during the declaration of a state of emergency. High communicative health literacy was associated with the implementation of exercise during this period.