Comparative inequalities in child dental caries across four countries : Examination of international birth cohorts and implications for oral health policy

Child dental caries (i.e., cavities) are a major preventable health problem in most high-income countries. The aim of this study was to compare the extent of inequalities in child dental caries across four high-income countries alongside their child oral health policies. Coordinated analyses of data were conducted across four prospective population-based birth cohorts (Australia, n = 4085, born 2004; Quebec, Canada, n = 1253, born 1997; Rotterdam, the Netherlands, n = 6690, born 2002; Southeast Sweden, n = 7445, born 1997), which enabled a high degree of harmonization. Risk ratios (adjusted) and slope indexes of inequality were estimated to quantify social gradients in child dental caries according to maternal education and household income. Children in the least advantaged quintile for income were at greater risk of caries, compared to the most advantaged quintile: Australia: AdjRR = 1.18, 95%CI = 1.04-1.34; Quebec: AdjRR = 1.69, 95%CI = 1.36-2.10; Rotterdam: AdjRR = 1.67, 95%CI = 1.36-2.04; Southeast Sweden: AdjRR = 1.37, 95%CI = 1.10-1.71). There was a higher risk of caries for children of mothers with the lowest level of education, compared to the highest: Australia: AdjRR = 1.18, 95%CI= 1.01-1.38; Southeast Sweden: AdjRR = 2.31, 95%CI = 1.81-2.96; Rotterdam: AdjRR = 1.98, 95%CI = 1.71-2.30; Quebec: AdjRR = 1.16, 95%CI = 0.98-1.37. The extent of inequalities varied in line with jurisdictional policies for provision of child oral health services and preventive public health measures. Clear gradients of social inequalities in child dental caries are evident in high-income countries. Policy related mechanisms may contribute to the differences in the extent of these inequalities. Lesser gradients in settings with combinations of universal dental coverage and/or fluoridation suggest these provisions may ameliorate inequalities through additional benefits for socio-economically disadvantaged groups of children.
Funding Agencies|Canadian Institutes of Health Research [MOP-123079, HDF70335, OCO-79897, MOP-89886, MSH-95353, ROG-110537]; Australian Government Department of Social Services; Australian Bureau of Statistics (ABS); Australian Institute of Family Studies (AIFS); Erasmus Medical Center, Rotterdam; Erasmus University Rotterdam; Netherlands Organisation for Health Research and Development (ZonMw) [907.00303, 916.10159]; Netherlands Organisation for Scientific Research (NWO); Ministry of Health, Welfare and Sport; Ministry of Youth and Families; lInstitut de la statistique du Quebec; Fondation Lucie et Andre Chagnon; Ministere de lEducation et de lEnseignement superieur; Ministere de la Santeet des Services sociaux; Ministere de la Famille; GRIP Research Unit on Childrens Psychosocial Maladjustment; QUALITY Cohort Collaborative Group; le Centre hospitalier universitaire SainteJustine; Institut de recherche Robert-Sauveen santeet en securiteau travail; lInstitut de recherche en santepublique de lUniversite de Montreal; Centre de recherche du Centre hospitalier de lUniversite de Montreal (CRCHUM); Fonds de recherche du Quebec Sante (FRQS); Fonds de recherche du Quebec Socie te et culture (FRQSC); Social Sciences and Humanities Research Council (SSHRC); County Council of Ostergotland; Swedish Research Council [K200572X-11242-11A, K2008-69X-20826-01-4]; Swedish Child Diabetes Foundation (Barndiabetesfonden); Juvenile Diabetes Research Foundation; Wallenberg Foundation [K 98-99D12813-01A]; Medical Research Council of Southeast Sweden (FORSS); Swedish Council for Working Life and Social Research [FAS20041775]; Ostgota Brandstodsbolag; Australian National Health and Medical Research Council (NHMRC) Practitioner Fellowship [1155290]; NHMRC Career Development Fellowship [1111160]; Victorian Governments Operational Infrastructure Program