Socioeconomic Inequalities in the Oral Health of People Aged 15-40 Years in Kurdistan, Iran in 2015: A Cross-sectional Study

Decomposition Analysis of Socioeconomic Inequalities in Utilization of Oral Health Services: A Population-Based Study in Urban and Rural Households of Ahvaz

Background

Inequality in the use of dental services is a primary concern of global health, and few studies have been done in this field in Iran. Therefore, the present study aimed to conduct a decomposition analysis of socioeconomic inequalities in the utilization of oral health services.

Methods

This was a cross-sectional study in which 715 households, including 2680 people living in Ahvaz, were included using a stratified-cluster sampling. Data were collected using a questionnaire. For data analysis and estimating the elasticity of the influencing factors, the logistic model and Stata software were used. The social and economic disparities in oral health variables were broken down into determinant components using the Van Doorslaer and Wagstaff technique.

Results

The key factors determining social and economic inequalities in the utilization of these services were insurance status, education level, income quintile, and occupation. Nearly 31% of utilization inequalities can be attributed to the insurance status of households. In addition, the education level of household members (about 28%) was the second factor of inequality. The variables of income quintile and occupation are also considered as the third factor, and the age of household members had a negative role in the socioeconomic inequality.

Conclusion

The utilization of oral health services can be improved by improving economic and social variables in society. Therefore, including oral health services in insurance plans and primary health care services and supporting people with low-income levels can play an important role in reducing these inequalities.

Utilization of dental care among adult populations: a scoping review of applied models

BACKGROUND

The timely and appropriate utilization of dental health care is essential to the prevention and accurate treatment of oral diseases. Therefore, it is crucial that managers, health professionals and healthcare providers be fully aware of the predictors encouraging the utilization of dental services and reduce social inequalities. In this scoping review, we aimed to analyze the published articles and reports to find out the factors associated with dental services utilization and the comprehensiveness of the applied models among general adult populations.

MATERIALS AND METHODS

This scoping study was based on the 5-steps of Arksey and O'Malley framework. Keywords were selected under two main concepts: determinants of dental care utilization and the concept of the applied models. Searches were conducted in some electronic databses including PubMed, Google Scholar and Scopus with variations, and a combination of the keywords under the two main afore-mentioned concepts. All the relevant articles reporting the utilization of dental care and its potential predictors among adult populations were chosen. No restrictions involving terms of study time, location or methodological aspects of oral health utilization were considered. Using tables and charts mapping, we tried to group the studies based on the year of their publication, geographic distribution, the range of included indices and the type of their measurement. Also, a directed content analysis method was used to investigate the comprehensiveness of the studies in regard to considering the determinant factors at different levels suggested by the Andesen model.

RESULTS

Fifty-two articles were included in the analysis. Thirty-six (69%) had been published between 2016 and 2020. The United States had conducted the most research in this scope. About 30% of studies had mentioned all three domains of demographics, social structure and beliefs, simultaneously. To evaluate the enabling factors, in 84.61% and 59.61% of studies, the income levels and insurance feature were assessed, respectively. 57.69% of the retrieved studies considered the perceived need features and 38.46% referred to the evaluated ones. The dental services utilization, in terms of the last visit during the "past 12 months", was assessed more commonly. Only 11.54% of studies did evaluate the contextual characteristics and about 71.15% of articles were relatively comprehensive.

CONCLUSION

Overall, it seems that in most of the studies, not all of the determinant factors at different levels of the Andersen model have been considered. In order to discover the conceptual linkages and feedback loops of the model, it is essential to conduct more comprehensive research in the future.

The prevalence of seat belt use among drivers and passengers: a systematic review and meta-analysis

BACKGROUND

Seat belts might save people's lives in car accidents by preventing severe collision damage and keeping passengers safe from critical injuries. This meta-analysis was performed to assess the prevalence of seat belt use among drivers and passengers.

METHODS

The databases of PubMed, Web of Science (WOS), and Google Scholar were searched from the beginning of 2000 to late December 2020 to identify studies that investigated the prevalence of seat belt use among drivers and passengers. The pooled prevalence was calculated using a random-effects model. The STATA-v14 software was used to perform data analysis.

RESULTS

Sixty-eight studies that met the inclusion criteria and were suitable for this meta-analysis were identified. The pooled prevalence of seat belt use was 43.94% (95% CI: 42.23-45.73) among drivers, 38.47% (95% CI: 34.89-42.42) among front-seat passengers, and 15.32% (95% CI: 12.33-19.03) among rear-seat passengers. The lowest seat belt use among drivers and passengers was observed in Asia, the Middle East, and Africa, while the highest use was reported in Europe and America. Moreover, the prevalence of seat belt use was higher among women drivers [51.47% (95% CI: 48.62-54.48)] than men drivers [38.27% (95% CI: 34.98-41.87)] (P < 0.001). Furthermore, the highest prevalence of seat belt use was seen among drivers (68.9%) and front-seat passengers (50.5%) of sports utility vehicles (SUVs); in contrast, the lowest prevalence was observed among drivers and passengers of public vehicles such as buses, minibuses, and taxis.

CONCLUSIONS

In general, the prevalence of seat belt use was not high among drivers and was even lower among passengers. Moreover, drivers and passengers in Asia, the Middle East, and Africa had the lowest prevalence of seat belt usage. Additionally, drivers and passengers of public transportation (buses, minibuses, and taxis) had a lower rate of seat belt use, especially among men. Therefore, effective interventional programs to improve seat belt use should be designed and implemented, particularly among these at-risk populations in Asia, the Middle East, and Africa.

Inequality in dental care expenditure in Iranian households: analysis of income quintiles and educational levels

Background

Oral health is a major public health issue which affects the human life. Access to dental care is one of the important factors in maintaining oral health. This study was aimed to investigate inequality in dental care expenditure in Iranian households.

Methods

The present study is a secondary analysis of a national cross-sectional survey. The data collected from the Households Income and Expenditure Survey in 2016 and 2017. The final sample consisted of 54,354 households living in rural and urban regions of all the provinces. Inequalities in household’s dental care expenditure per capita in respect to income quintiles and educational level were measured based on the Gini coefficient and concentration index.

Results

The results showed that about 8% of households had paid for dental care during the month before sampling. The Gini coefficient value was estimated to be 0.97 and 0.96 for dental care expenditure per capita respectively in absolute and relative measure. It indicated a significant inequality in the dental expenditure among the sample households. The values of concentration index were positive and significant for all dental care subcategories in respect to the provincial and national income quintiles as well as the educational level of the head of the household.

Conclusions

Income and educational inequality in the both absolute and relative dental services expenditure of the Iranian households were in favor of higher income groups as well as higher educational level of household heads. Income inequality was higher in total dental care expenditure per capita and all its subcategories than the educational inequalities of dental expenditure. In order to reduce these inequalities, the policymakers need to pay special attention to low-income households, particularly those with low-educated heads.

Catastrophic health expenditures for children with disabilities in Iran: A national survey

OBJECTIVE

The aim of this study was to investigate the percentage of households with disabled children aged 0-8 years who had faced catastrophic health expenditures (CHEs) due to the health costs of these children in Iran.

METHODS

This cross-sectional study was carried out on 2000 households with disabled children aged 0-8 years in five provinces of Iran in 2020. Data were collected using the World Health Survey questionnaire and face-to-face interview. Determinants of CHE were identified using logistic regression.

RESULTS

32.7% of households with disabled children had faced CHE. Head of household being female (Adjusted OR = 18.89, 95%CI: 10.88-29.42), poor economic status of the household (Q1: Adjusted OR = 20.26, 95% CI, 11.42-35.94; Q2: Adjusted OR = 8.27, 95%CI, 4.45-15.36; Q3: Adjusted OR = 13.88, 95%CI, 7.89-24.41), lack of supplementary insurance by a child with disabilities (Adjusted OR = 6.13, 95%CI, 3.39-11.26), having a child with mental disability (Adjusted OR = 2.71, 95%CI, 1.60-4.69), and type of basic health insurance (having Iranian Health Insurance: Adjusted OR = 2.20, 95%CI, 1.38-3.49; having Social security insurance: Adjusted OR = 1.66, 95%CI, 1.06-2.61) significantly increased the chances of facing CHE.

CONCLUSION

A significant percentage of households with disabled children had faced CHE because of their disabled child's health costs. The key determinants of CHE should be considered by health policy-makers in order to more financial protection of these households.

Socioeconomic inequalities in tobacco smoking in women aged 15-54 in Iran: a multilevel model

Significant evidence suggests an inverse relationship between socioeconomic status and tobacco smoking, where inequality is visible among different social and economic strata. The aim of this study was to investigate the prevalence and economic and social inequalities in tobacco smoking in women aged 15-54 in Iran. This study is a cross-sectional study. Sampling in this study was a randomized clustered multistage sampling with equal clusters. A total of 35,305 women aged 15-55 enrolled in the study. Data analysis was in two stages. In the first stage, the social and economic inequalities were investigated using the concentration index and concentration curve method, and in the second method, and multilevel method was used to identify the determinants. The prevalence of tobacco smoking in women was 12.24%. The concentration index for smoking was CI = -0.07 [95% CI (-0.09, -0.05)], which represents smoking in people with low socioeconomic status. The results of the multilevel analysis indicated that the marital status of people over the age of 35 and the economic class was related to smoking in women. Inequality in tobacco smoking in women is to the interest of the well-off group, and this inequality varies in different provinces. Marital status, place of residence, age and socioeconomic status of women are factors influencing the prevalence of tobacco smoking in women, and these issues should be noticed to reduce inequalities.

Health equity in Iran: A systematic review

Background: Health inequities are among debatable and challenging aspects of health systems. Achieving equity through social determinants of health approach has been mentioned in most upstream national plans and acts in Iran. This paper reports the findings of a systematic review of the current synthesized evidence on health equity in Iran.

Methods: This is a narrative systematic review. The relevant concepts and terminology in health equity was found through MeSH. We retrieved the relevant studies from PubMed/MedLine, Social Sciences Database, and Google Scholar in English, plus the Jihad University Database (SID), and Google Scholar in Farsi databases from 1979 until the end of January 2018. The retrieved evidence has been assessed primarily based on PICOS criteria and then Ottawa-Newcastle Scale, and CASP for qualitative studies. We used PRISMA flow diagram and a narrative approach for synthesizing the evidence.

Results: We retrieved 172 455 studies. Following the primary and quality appraisal process, 114 studies were entered in the final phase of the analysis. The main part (approximately 95%) of the final phase included cross-sectional studies that had been analyzed through current descriptive inequality analysis indicators, analytical regression, or decomposition-based approaches. The studies were categorized within 3 main groups: health outcomes (40.3%), health utilization (32%), and health expenditures (27%).

Conclusion: As a part of understanding the current situation of health equity in the policymakers’ need to refer the retrieved evidence in this study, they need more inputs specially regarding the social determinants of health approach. It seems that health equity research plan in Iran needs to be redirected in new paths that give appropriate weights to biological, gene-based, environmental and contextbased, economic, social, and political aspects of health as well. We advocate addressing the aspects of Social Determinant of Health (SDH) in analyzing health inequalities.

Evaluating the quality of care for patients with type 2 diabetes mellitus based on the HbA1c: A national survey in Iran

Objective

The present study was conducted to evaluate the quality of care for type2 diabetic patients based on the HbA1c in Iran.

Materials and methods

This cross-sectional study was conducted in 2019 among patients with type 2 diabetes in Iran. The data were collected through a three-part questionnaire including demographic information, disease-related records, and HbA1C status of patients. Multiple logistic regression was used to investigate the relationship between the outcome variable (HbA1c status) and the independent variables in Stata 12.

Results

The mean HBA1c was 8.01 ± 1.76% among 1,198 diabetic patients, and more than 66% of them had HBA1c above 7%, i.e. they had uncontrolled blood sugar levels. HBA1c has the highest average among people with more than 10 years of diabetes (8.47 ± 1.77%), self-employed people (8.36 ± 1.94%), illiterate people or those with elementary education (8.13 ± 1.76%) and people with poor economic status (8.12 ± 1.79%). Also, in the final model, people with more than 10 years of disease history had the highest prevalence of HBA1C > 7 with a chance ratio of 3.28 (P < 0.001, 95%CI: 2.37–4.53) and followed by illiterate people or those with elementary education with a chance ratio of 1.6 (P = 0.020, 95%CI: 1.08–2.39) compared to those with high school diploma or academic education.

Conclusion

The prevalence of adverse HBA1c in 66% of the studied subjects indicates an inappropriate status of diabetes control in Iran. This indicates the poor quality of services provided to the diabetics. This is a warning sign and requires appropriate interventions to improve the quality of services provided to diabetic patients.

Socioeconomic inequality in dental caries experience expressed by the significant caries index: cross-sectional results from the RaNCD Cohort Study

INTRODUCTION

Socioeconomic inequality in dental caries among Iranian middle-aged adults remains largely unstudied. This study aimed to measure socioeconomic inequality in dental caries experience and to identify determinants of this inequality.

MATERIALS AND METHODS

Data were obtained from the Ravansar Non-Communicable Diseases (RaNCD) Cohort Study. This cross-sectional analysis included 10,002 adults aged 35-65 years. Caries experience was dichotomised based on the decayed, missing and filled teeth (DMFT) of one-third of the population with the highest caries scores (i.e. significant caries index). Socioeconomic status (SES) was calculated using the principal component analysis. The concentration index (CI) was used to quantify the extent of socioeconomic inequality in dental caries experience. Decomposition analysis was conducted to quantify the contribution of each determinant to the observed inequality.

RESULTS

The mean DMFT for all individuals was 16.1(SD 9.1). The CI of having significant dental caries was -0.236 (95% CI: -0.0259, -0.213), indicating that having significant dental caries was more concentrated among low-SES individuals. SES (65.6%), age group (24.7%) and female gender (3.7%) were found to have the largest percentage of contributions to the observed inequality in dental caries.

CONCLUSION

This study indicates pro-rich inequalities in dental caries experience among middle-aged adults in Iran. The findings highlight the importance of early prevention of dental caries experience before it happens. To mitigate inequalities in dental caries experience, policy interventions should focus on females, older age groups, and low-SES individuals.

Oral Health Behaviors among Schoolchildren in Western Iran: Determinants and Inequality

Introduction

Little information exists on the status of oral hygiene behavior (OHB) and socioeconomic inequalities in developing countries like Iran. The aim of this study was to assess OHB and its determinants and socioeconomic inequality among schoolchildren in western Iran during 2018.

Methods

A cross-sectional survey was conducted on 1,457 students aged 12–15 years living in Kermanshah city, western Iran. We used multistage sampling to select the samples. A self-administrated questionnaire was used to collect data on OHB, sociodemographic characteristics, and economic status of the households of students. Multivariate logistic regression was used to examine the association between OHB and its determinants. We used the relative concentration index, normalized (RCIn) and a concentration curve (CC) to examine socioeconomic-related inequality in OHB.

Results

The study indicated that crude and age-adjusted prevalence of good OHB was 14.61% (95% CI 12.89%–16.53%) and 15.17% (95% CI 13.22%–17.35%), respectively. Logistic regression analysis showed that sex, mother’s education, socioeconomic status, and oral health literacy had a statistically significant positive impact on OHB. RCIn (0.2582, 95% CI0.1770–0.3395) values and the CC indicated that good OHB was more concentrated among the richer children.

Conclusion

This study provides evidence that good OHB was less prevalent, signifying that oral health remains a public-health concern in Iran. Effective polices aimed at improving the socioeconomic status of households and mother’s education can contribute positively and to the prevention of oral disorders among schoolchildren.

Decomposing socioeconomic inequality in dental caries in Iran: cross-sectional results from the PERSIAN cohort study

Background

The current study aimed to measure and decompose socioeconomic-related inequalities in DMFT (decayed, missing, and filled teeth) index among adults in Iran.

Methods

The study data were extracted from the adult component of Prospective Epidemiological Research Studies in IrAN (PERSIAN) from 17 centers in 14 different provinces of Iran. DMFT score was used as a measure of dental caries among adults in Iran. The concentration curve and relative concentration index (RC) was used to quantify and decompose socioeconomic-related inequalities in DMFT.

Results

A total of 128,813 adults aged 35 and older were included in the study. The mean (Standard Deviation [SD]) score of D, M, F and DMFT of the adults was 3.3 (4.6), 12.6 (10.5), 2.1 (3.4) and 18.0 (9.5), respectively. The findings suggested that DMFT was mainly concentrated among the socioeconomically disadvantaged adults (RC = - 0.064; 95% confidence interval [CI), - 0.066 to - 0.063). Socioeconomic status, being male, older age and being a widow or divorced were identified as the main factors contributing to the concentration of DMFT among the worse-off adults.

Conclusions

It is recommended to focus on the dental caries status of socioeconomically disadvantaged groups in order to reduce socioeconomic-related inequality in oral health among Iranian adults. Reducing socioeconomic-related inequalities in dental caries should be accompanied by appropriate health promotion policies that focus actions on the fundamental socioeconomic causes of dental disease.

Reducing social inequalities in the oral health of an adult population

The objective of this study was to evaluate the association between social inequality indicators and oral health conditions in an adult population. This prospective cohort study assessed a probabilistic sampling of adults (aged 20-64 years) living in Piracicaba, São Paulo, Brazil. Oral examinations were performed in 2011 and 2015, conducted at home, and used the decay-missing-filled (DMFT) index of permanent teeth, the Community Periodontal Index (CPI), and the visible biofilm criterion. A questionnaire was administered to determine demographic and socioeconomic aspects and dental services used, and collect oral health-related quality of life (OHRQoL) data. Social inequality indicators were evaluated according to social class (high, middle or low) and type of dental service used (public, health insurance or private), and compared with oral health conditions (visible biofilm, DMFT and incidence of tooth loss, periodontal pockets and bleeding, and OHRQoL), evaluated between 2011 and 2015. Analysis using chi-squared or Fisher tests (p < 0.05) and Cochran's Q test was conducted separately for each category analyzed between 2011 and 2015 (p < 0.05). A total of 143 adults who participated in an earlier study were examined after four years of follow-up. Although the occurrence of oral disease did not decrease over the study period (4 years), there was a reduction in inequality among lower social classes in regard to presence of tooth decay and oral health impact on self-perceived quality of life between 2011 and 2015 (p < 0.05). These results suggest that the Brazilian National Oral Health Policy has achieved its principles, especially that of greater equity.

Incidence and Intensity of Catastrophic Health-care Expenditure for Type 2 Diabetes Mellitus Care in Iran: Determinants and Inequality

BACKGROUND

The present study aimed to assess the prevalence and intensity of catastrophic health-care expenditures (CHE) relating to type 2 diabetes mellitus care and inequality in facing such expenditures in Iran.

METHODS

A total of 1065 type 2 diabetes patients were included in this cross-sectional study. A multistage sampling method was used to select the samples. Data on sociodemographic characteristics, economic status, health and diabetic costs were collected using a self-constructed questionnaire. We used capacity to pay (CTP) of households to calculate the incidence of CHE due to diabetic care at four different thresholds. The mean positive overshoot (MPO) and overshoot were used to assess the intensity of CHE. The relative concentration index and slope index of inequality (SII) were used to measure socioeconomic-related inequalities in incidences of CHE. In addition, decomposition methods were used to identify the main factors affecting observed inequality in CHE.

RESULTS

The incidence of CHE at the 10, 20, 30, and 40% of CTP thresholds for type 2 diabetes mellitus care was 57.5, 28.9, 16.5, and 11.4%, respectively. The results of CI and SII indices for CHE due to diabetic care indicated that the incidence of CHE was more prevalent among patients with lower socioeconomic groups. The decomposition analysis showed that the socioeconomic status, marital status and gender of patients were the main factors contributing to socioeconomic inequality in incidence of CHE among the poor.

CONCLUSION

Our study demonstrated that the incidence and intensity of CHE due to diabetic care were relatively high, particularly among socioeconomically disadvantaged patients. Modification to the present health care financing strategies is recommended in order to protect lower socioeconomic groups against the financial burden of diabetic care.

Evaluation of Oral Health Status Based on the Decayed, Missing and Filled Teeth (DMFT) Index

BACKGROUND

The Decayed, Missing and Filled Teeth (DMFT) is a valuable index used for determining and monitoring the oral health status in a community. This study aimed to determine the oral health status and its associated factors based on the DMFT index among people aged 15 to 45 yr old in Kurdistan Province, west of Iran.

METHODS

This study was conducted on 2000 people aged 15-40 yr old in Kurdistan, western Iran in 2015. Using a questionnaire, data were collected by four trained dental students. The dependent variable was the DMFT index. The collected data were analyzed using T-test, ANOVA, Pearson statistics, Kendall statistics, and multiple regression.

RESULTS

The mean (SD) values of Decayed teeth (DT), Missing teeth (MT), and Filled teeth (FT) indices in the participants were 2.85±1.7, 1.15±1.84, and 3.33±1.7, respectively. The mean (SD) value of total DMFT index was 7.33±3.0. The results of multiple regression showed that the frequency of using dental floss (coefficient= -0.296, P=0.001), socio-economic status (coefficient=-0.199, P=0.001), parental education (coefficient= -0.183, P=0.001), frequency of brushing (coefficient=-0.182, P=0.001), and frequency of the use of mouthwash (coefficient=-0/143, P=0.001) had the highest level of with association with the DMFT index.

CONCLUSION

The oral health status of the adult population is alarming and undesirable. The oral and dental health status can be improved via changing behavioral habits (such as brushing, using mouthwashes, and dental floss), promoting socioeconomic status, increasing individual's and parent's level of education, and enhancing people's access to health insurance.

Catastrophic health expenditure and its determinants in households with gastrointestinal cancer patients: evidence from new health system reform in Iran

Purpose

The right to health for all people means that everyone should have access to the needed healthcare services without suffering from severe financial hardship. The purpose of this paper is to investigate the prevalence as well as the effective factors on facing catastrophic health expenditures (CHE) among gastrointestinal cancer patients and families in Kurdistan province in west of Iran after the implementation of Health Transformation Plan (HTP).

Design/methodology/approach

A cross-sectional study was carried out on 189 households with gastrointestinal cancer patients in Kurdistan province in 2018. Data were collected using World Health Survey questionnaire. A method developed by World Health Organization with the threshold of 40 percent household’s capacity to pay was used in order to measure the proportion of households facing CHE. Also, logistic regression was applied for identifying the effective factors on household’s exposure to CHE. Data were analyzed using STATA version 13.

Findings

Almost 73 percent (72.7 percent) of the households (n=117) faced the CHE. Not having supplementary health insurance (adjusted odds ratio (AOR): 3.8; 95% confidence interval: 1.3–10.8 (and having low socio-economic status (AOR: 7.1; 95% CI: 1.8–28.1) were the significant factors affecting the households’ exposure to CHE. In total, 57 and 1 percent of the studied households reported that having a gastrointestinal cancer patient at home had a significant effect on refraining from using health services by other family members.

Originality/value

The proportion of the studied households facing CHE was very high. This may indicate the weakness of health system as well as health insurance or the weakness of HTP in financial protection of fragile population.

Age-sex specific and sequela-specific disability-adjusted life years (DALYs) due to dental caries preventable through water fluoridation: An assessment at the national and subnational levels in Iran, 2016

We assessed disability-adjusted life years (DALYs) due to dental caries preventable through water fluoridation apportioned by sex, age group, sequela, province, and community type in Iran, 2016. The burden of disease due to dental caries was extracted from the Global Burden of Disease Study 2016 (GBD 2016) and the caries preventive effect of water fluoridation was calculated using a database of fluoride levels in drinking water. All the preventable DALYs were caused by years lived with disability (YLDs) because of the non-fatal character of dental caries. DALYs and DALY rate (per 100,000 people) preventable through water fluoridation at the national level in 2016 were 14,971 (95% uncertainty interval 7348- 24,725) and 18.73 (9.19-30.93), respectively. The national population preventable fraction (PPF) of dental caries by water fluoridation was determined to be as high as 0.176 (0.141-0.189). The share of sequelae in the preventable DALYs at the national level were estimated to be 76.8% for edentulism and severe tooth loss, 21.4% for caries of permanent teeth, and 1.8% for caries of deciduous teeth. The national DALYs and DALY rate preventable through water fluoridation exhibited no difference by sex, but considerably increased by age from 110 (37-223) and 1.5 (0.5-3.1) for the age group 0-4 y to 4331 (2334-6579) and 88.9 (47.9-135.1) for the age group 65 y and older, respectively. Over 80% of the national preventable DALYs occurred in urban areas due to higher population and lower coverage of fluoridated drinking water. The highest provincial DALYs and DALY rate preventable by water fluoridation were observed in Tehran and Gilan to be 3776 (1866-6206) and 37.2 (18.6-60.8), respectively. The results indicated that water fluoridation can play a profound role in the promotion of dental public health and compensate the spatial inequality and increasing temporal trend of health losses from dental caries at the national level.

Socioeconomic status, oral health and dental disease in Australia, Canada, New Zealand and the United States

BACKGROUND

Socioeconomic inequalities are associated with oral health status, either subjectively (self-rated oral health) or objectively (clinically-diagnosed dental diseases). The aim of this study is to compare the magnitude of socioeconomic inequality in oral health and dental disease among adults in Australia, Canada, New Zealand and the United States (US).

METHODS

Nationally-representative survey examination data were used to calculate adjusted absolute differences (AD) in prevalence of untreated decay and fair/poor self-rated oral health (SROH) in income and education. We pooled age- and gender-adjusted inequality estimates using random effects meta-analysis.

RESULTS

New Zealand demonstrated the highest adjusted estimate for untreated decay; the US showed the highest adjusted prevalence of fair/poor SROH. The meta-analysis showed little heterogeneity across countries for the prevalence of decayed teeth; the pooled ADs were 19.7 (95% CI = 16.7-22.7) and 12.0 (95% CI = 8.4-15.7) between highest and lowest education and income groups, respectively. There was heterogeneity in the mean number of decayed teeth and in fair/poor SROH. New Zealand had the widest inequality in decay (education AD = 0.8; 95% CI = 0.4-1.2; income AD = 1.0; 95% CI = 0.5-1.5) and the US the widest inequality in fair/poor SROH (education AD = 40.4; 95% CI = 35.2-45.5; income AD = 20.5; 95% CI = 13.0-27.9).

CONCLUSIONS

The differences in estimates, and variation in the magnitude of inequality, suggest the need for further examining socio-cultural and contextual determinants of oral health and dental disease in both the included and other countries.