Effects of Community Water Fluoridation on Dental Caries Disparities in Adolescents

Motivations for investigating health inequities in observational epidemiology: a content analysis of 320 studies

OBJECTIVES

To enhance equity in clinical and epidemiological research, it is crucial to understand researcher motivations for conducting equity-relevant studies. Therefore, we evaluated author motivations in a randomly selected sample of equity-relevant observational studies published during the COVID-19 pandemic.

STUDY DESIGN AND SETTING

We searched MEDLINE for studies from 2020 to 2022, resulting in 16,828 references. We randomly selected 320 studies purposefully sampled across income setting (high vs low-middle-income), COVID-19 topic (vs non-COVID-19), and focus on populations experiencing inequities. Of those, 206 explicitly mentioned motivations which we analyzed thematically. We used discourse analysis to investigate the reasons behind emerging motivations.

RESULTS

We identified the following motivations: (1) examining health disparities, (2) tackling social determinants to improve access, and (3) addressing knowledge gaps in health equity. Discourse analysis showed motivations stem from commitments to social justice and recognizing the importance of highlighting it in research. Other discourses included aspiring to improve health-care efficiency, wanting to understand cause-effect relationships, and seeking to contribute to an equitable evidence base.

CONCLUSION

Understanding researchers' motivations for assessing health equity can aid in developing guidance that tailors to their needs. We will consider these motivations in developing and sharing equity guidance to better meet researchers' needs.

Associations between school-based fluoride mouth-rinse program, medical-dental expense subsidy policy, and children's oral health in Japan: an ecological study

BACKGROUND

Dental caries are a common non-communicable disease among children. As a public health measure at the prefectural level, school-based fluoride mouth-rinse (S-FMR) program, medical/dental expense subsidy policies, and other factors may reduce the incidence of dental caries and tooth loss. Prefectures focusing on promoting oral health policies may promote both, but the interaction effect of implementing both subsidy policies and S-FMR at the prefectural level on caries prevention has not yet been examined.

METHODS

We conducted an ecological study using two-wave panel data, prefecture-level aggregated data in Japan for 2016 and 2018. Coefficient and 95% confidence intervals (CI) were calculated for the dependent variables for oral health using mixed-effects linear regression analysis adjusted for possible confounders. Two dependent variables were used; the standardized claim ratio (SCR) of deciduous tooth extraction and 12-year-olds' decayed, missing, or filled permanent teeth (DMFT). Four independent variables were S-FMR, the SCR of dental sealants, prefectural income per person, and subsidy policy in three models: co-payment until children enter elementary school (n = 23), no co-payment until children enter elementary school (n = 7), and co-payment continuing beyond elementary school (n = 17). The effects of six interaction terms, each representing a unique pairing from the four independent variables, were individually calculated.

RESULTS

S-FMR was negatively associated with the SCR of deciduous tooth extractions and DMFT (coefficient = -0.11, 95% CI -0.20; -0.01 and coefficient = -0.003, 95% CI -0.005; -0.001, respectively). No co-payment until children enter elementary school was positively associated with the SCR of deciduous tooth extraction compared to co-payment until children enter elementary school(coefficient = 11.42, 95% CI 3.29; 19.55). SCR of dental sealants was positively associated with the SCR of deciduous tooth extractions (coefficient = 0.12, 95% CI 0.06; 0.19) but negatively associated with DMFT (coefficient = -0.001, 95% CI -0.003; -0.0001). Per capita prefectural income was positively associated with the SCR of deciduous tooth extractions(coefficient = 0.01, 95% CI 0.001; 0.02). No interaction was found between S-FMR and the subsidy policy at both outcomes.

CONCLUSION

High S-FMR utilization and no co-payment until children enter elementary school were associated with fewer deciduous tooth extractions. Also, S-FMR and dental sealant were associated with decreased DMFT.

National and Subnational Trend of Dental Caries of Permanent Teeth in Iran, 1990-2017

OBJECTIVE

There are currently no integrated data on the trend of dental caries amongst distinct age groups in Iran. We aimed to assess the national and subnational trend of dental caries of permanent teeth in Iran from 1990 to 2017.

METHODS

A literature search about dental caries and the decayed-missing-filled teeth index (DMFT) was performed in PubMed, Web of Science, Scopus, and 3 national databases (in Persian). All eligible national oral health surveys in these 28 years were included. We categorised and aggregated the DMFT values and their components based on age (5-year-based groups from 5 to 9 to 60+ years), sex, year, and province. The data for missing spots were estimated using the spatiotemporal Bayesian hierarchical model. We used the bootstrap method in multilevel models to predict the uncertainty interval (UI) of the modelled results.

RESULTS

Nationally, the all-ages mean DMFT increased by nearly 58.0% (6.8 [95% UI, 4.1-10.5] in 1990 to 10.8 [95% UI, 7.5-14.5] in 2017). Decayed teeth (DT) and missing teeth (MT) rose by 84.5% and 31.6% during this period, respectively. Filled teeth (FT) showed almost a 2.6-fold increase in the same period from 0.6 (95% UI, 0.01-1.6) in 1990 to 1.7 (95% UI, 0.6-2.8) in 2017. The proportion of DT and FT continuously increased in both sexes. In 2017, the highest DT, MT, and FT were estimated in the 25-29 (4.9 [95% UI, 2.5-7.2]), 60+ (21.5 [95% UI, 17.5-25.4]), and 35-39 (2.6 [95% UI, 1.3-4.0]) year age groups.

CONCLUSIONS

Caries of permanent dentition levies a growing burden on the Iranian population. Considering the continuous increase in caries during the 1990-2017 period, Iranian policymakers should pay heed to these findings and react more proactively to mitigate this perpetuating issue. Implementing nationwide interventions such as sugar consumption management should be encouraged to achieve sustainable outcomes in this regards.

Pre- and Post-Pandemic (COVID-19) Mental Health of International Students: Data from a Longitudinal Study

Purpose

International students are highly vulnerable to the risk of mental health worsening before and during the pandemic (COVID-19). This study investigated international students' mental health pre- and post-pandemic (COVID-19).

Methods

It is a longitudinal study, and data were collected online, pre-pandemic (N = 470) and during the pandemic (N = 420). Using a random sampling technique, a self-administered questionnaire was used to measure mental health, including depression and anxiety.

Results

Findings show that international students' mental health was good in pre-pandemic. Meanwhile, international students were found to be more depressed and anxious during the pandemic. Findings also investigated that in the pre-pandemic phase, young students' and mainly females' mental health was worsened.

Conclusion

This study concluded that students' mental problems are alarming, so the university should provide psychological services for the student's mental health. Post-pandemic is leaving long-lasting psychological effects and will require further investigation.

Age period cohort analysis of chewing ability in Korea from 2007 to 2018

There have been marked improvements in oral health in Korea during the past 10 years, including chewing ability. We sought to disentangle age, period, and cohort effects in chewing ability between 2007 and 2018. We analyzed data from the Korea National Health and Nutrition Examination Survey. The main variable was chewing difficulty, which was assessed among participants aged 20 years and older. APC analysis revealed three trends in chewing difficulty: (1) there was an increase in chewing difficulty starting at around 60 years of age (age effect), (2) there was a steady decrease in chewing difficulty during the observation period (period effect), and (3) chewing ability improved with each successive generation born after 1951 (cohort effect). Regarding recent improvements in chewing ability, cohort effects were somewhat more important than period effects.

Cost-effectiveness of caries preventive interventions - a systematic review

OBJECTIVE

The primary purpose of this study was to assess the cost-effectiveness of caries preventive interventions.

MATERIAL AND METHODS

A systematic review was conducted, following the PRISMA Statement. Four electronic databases were searched (final search 16 March 2020). Studies fulfilling the inclusion criteria were independently critically appraised, by two reviewers in parallel. Data from each included study were extracted and tabulated: the analysis used a narrative approach to present the results of the estimated cost-effectiveness.

RESULTS AND CONCLUSIONS

Twenty-six publications fulfilled the inclusion criteria and were of low or moderate risk of bias. Ten publications were economic evaluations, directly based on empirical studies, and the other 16 were modelling studies. Most of the studies concerned interventions for children and the most common were analyses of fluoride varnish and risk-based programs. Some of the studies showed both reduced cost and improved outcomes, but most studies reported that the improved outcome came with an additional cost. The results disclosed several cost-effectiveness evaluations of caries preventive interventions in the literature, but these target primarily children at high risk. There is a scarcity of studies specifically targeting adults and especially the elderly.

Systematic Review of Intervention Studies Aiming at Reducing Inequality in Dental Caries among Children

(1) Background: The objective is to systematically review the evidence on intervention programs aiming at reducing inequality in dental caries among children. (2) Methods: Two independent investigators searched MEDLINE, Cochrane library, and Ovid up to December 2020 to identify intervention studies assessing the impact on socioeconomic inequalities in dental caries among children. The interventions included any health promotion/preventive intervention aiming at reducing caries among children across different socioeconomic groups. Comparison groups included children with alternative or no intervention. Cochrane criteria were used to assess interventional studies for risk of bias. (3) Results: After removal of duplicate studies, 1235 articles were retained. Out of 43 relevant papers, 13 articles were identified and used in qualitative synthesis, and reported quantifiable outcomes. The included studies varied in measurements of interventions, sample size, age groups, and follow-up time. Five studies assessed oral health promotion or health-education, four assessed topical fluorides, and four assessed water fluoridation. Interventions targeting the whole population showed a consistent reduction of socioeconomic inequalities in dental caries among children. (4) Conclusion: The quality of included papers was moderate. High heterogeneity did not allow aggregation of the findings. The overall findings suggest that whole population interventions such as water fluoridation are more likely to reduce inequalities in children’s caries than target population and individual interventions.