The authors declare that they have no competing interests.
KI participated in the acquired the data and the study design, performed the statistical analysis, and drafted the manuscript as the principal author. JA helped to develop the idea of the study, participated in the acquired the data, advised the statistical analysis, and edited the manuscript. TY participated in the acquired the data and the study design, and edited the manuscript. RO and MN participated in the acquired the data and reviewed the manuscript. KS helped to edit the manuscript, participated in its design, and advised the statistical analysis. KK is the principal investigator of the JAGES project, helped to develop the idea of the study, participated in the acquired the data and the study design, and edited the manuscript. KO participated in the acquired the data, helped with data analysis, and critically revised the manuscript. All authors read and approved the final manuscript.
Community-level factors as well as individual-level factors affect individual health. To date, no studies have examined the association between community-level social gradient and edentulousness. The aim of this study was to investigate individual- and community-level social inequalities in edentulousness and to determine any explanatory factors in this association.
We analyzed the data from the Japan Gerontological Evaluation Study (JAGES). In 2010-2012, 112,123 subjects aged 65 or older responded to the questionnaire survey (response rate = 66.3%). Multilevel logistic regression analysis was applied to determine the association between community-level income and edentulousness after accounting for individual-level income and demographic covariates. Then, we estimated the probability of edentulousness by individual- and community-level incomes after adjusted for covariates.
Of 79,563 valid participants, the prevalence of edentulousness among 39,550 men (49.7%) and 40,013 women (50.3%) were both 13.8%. Living in communities with higher mean incomes and having higher individual-level incomes were significantly associated with a lower risk of edentulousness (odds ratios [ORs] by 10,000 USD increments were 0.37 (95% confidence interval [CI] [0.22-0.63]) for community-level and 0.85 (95% CI [0.84-0.86]) for individual-level income). Individual- and community-level social factors, including density of dental clinics, partially explained the social gradients. However, in the fully adjusted model, both community- and individual-level social gradients of edentulousness remained significant (ORs = 0.43 (95% CI [0.27-0.67]) and 0.90 (95% CI [0.88-0.91]), respectively). One standard deviation changes in community- and individual-level incomes were associated with 0.78 and 0.84 times lower odds of edentulousness, respectively. In addition, compared to men, women living in communities with higher average incomes had a significantly lower risk of edentulousness (p-value for interaction < 0.001).
Individual- and community-level social inequalities in dental health were observed. Public health policies should account for social determinants of oral health when reducing oral health inequalities.
Yamamoto T, Kondo K, Hirai H, Nakade M, Aida J, Hirata Y. Association between self-reported dental health status and onset of dementia: a 4-year prospective cohort study of older Japanese adults from the Aichi Gerontological Evaluation Study (AGES) Project. Psychosom Med. 2012;74(3):241–8. PubMedCrossRef
Brennan SL, Holloway KL, Williams LJ, Kotowicz MA, Bucki-Smith G, Moloney DJ, et al. The social gradient of fractures at any skeletal site in men and women: data from the Geelong Osteoporosis Study Fracture Grid. Osteoporos Int. 2015. doi:10.1007/s00198-014-3004-y.
Ministry of Internal Affairs and Communications. Status Survey of Tax on Municipalities. The System of Social and Demographic Statistics of Japan, Basic data of Shi, Ku, Machi, Mura by Statistics Bureau, Ministry of Internal Affairs and Communications. 2010.
Hanibuchi T, Aida J, Nakade M, Hirai H, Kondo K. Geographical accessibility to dental care in the Japanese elderly. Community Dent Health. 2011;28(2):128–35. PubMed
Ministry of Health, Labour and Welfare. Survey of Medical Institutions. The System of Social and Demographic Statistics of Japan, Basic data of Shi, Ku, Machi, Mura by Statistics Bureau, Ministry of Internal Affairs and Communications. 2010.
Merlo J, Chaix B, Yang M, Lynch J, Rastam L. A brief conceptual tutorial on multilevel analysis in social epidemiology: interpreting neighbourhood differences and the effect of neighbourhood characteristics on individual health. J Epidemiol Community Health. 2005;59(12):1022–8. PubMedCentralPubMedCrossRef
Yamamoto T, Kondo K, Fuchida S, Aida J, Nakade M, Hirata Y. Validity of self-reported oral health variables: Aichi Gerontological Evaluation Study (AGES) project. Health Sci Health Care. 2012;12:4–12.
- Individual- and community-level social gradients of edentulousness
for the JAGES group
- BioMed Central
Neu im Fachgebiet Zahnmedizin
Mail Icon II