Abstract
Objectives: One argument made in favour of drinking water fluoridation is that it is equitable in its impact on oral health. We examined the association between exposure to fluoridation and oral health inequities among Canadian children.
Participants, setting and intervention: We analyzed data from 1,017 children aged 6–11 from Cycle 1 of the Canadian Health Measures Survey, a cross-sectional, nationally representative survey that included a clinic oral health examination and a household interview. The outcome measure was a count of the number of decayed, missing (because of caries or periodontal disease) or filled teeth, either deciduous or permanent (dmftDMFT). Data were analyzed using linear (ordinary least squares) and multinomial logistic regression; we also computed the concentration index for education-related inequity in oral health. Water fluoridation status (the intervention) was assigned on the basis of the site location of data collection.
Outcomes: Fluoridation was associated with better oral health (fewer dmftDMFT), adjusting for socio-economic and behavioural variables, and the effect was particularly strong for more severe oral health problems (three or more dmftDMFT). The effect of fluoridation on dmftDMFT was observed across income and education categories but appeared especially pronounced in lower education and higher income adequacy households. dmftDMFT were found to be disproportionately concentrated in lower-education households, though this did not vary by fluoridation status.
Conclusions: The robust main effect of fluoridation on dmftDMFT and the beneficial effect across socio-economic groups support fluoridation as a beneficial and justifiable population health intervention. Fluoridation was equitable in the sense that its benefits were particularly apparent in those groups with the poorest oral health profiles, though the nature of the findings prompts consideration of the values underlying the judgement of health equity.
Key words: Canada, fluoridation, oral health, socio-economic factors
Résumé
Objectifs: L’un des arguments en faveur de la fluoration de l’eau potable est qu’il s’agit d’une mesure dont l’impact sur la santé buccodentaire est équitable. Nous avons examiné l’association entre l’exposition à la fluoration et les inégalités en santé buccodentaire chez les enfants canadiens.
Participants, lieu et intervention: Nous avons analysé les données de 1 017 enfants de 6 à 11 ans tirées du 1er cycle de l’Enquête canadienne sur les mesures de la santé, une enquête transversale représentative à l’échelle du pays qui comporte un examen clinique de la santé buccodentaire et un entretien avec le ménage. Notre mesure de résultat était le décompte des dents cariées, manquantes (en raison de caries ou de maladies parodontales) ou plombées, temporaires ou permanentes (dcmpDCMP). Les données ont été analysées par régression logistique linéaire (méthode ordinaire des moindres carrés) et multinomiale; nous avons aussi calculé l’indice de concentration pour les inégalités en santé buccodentaire liées à la scolarité. La fluoration ou non de l’eau (l’intervention) a été déterminée selon l’emplacement du site de collecte des données.
Résultats: La fluoration était associée à une meilleure santé buccodentaire (moins de dcmpDCMP), compte tenu de diverses variables socioéconomiques et comportementales, et cet effet était particulièrement fort pour les problèmes de santé buccodentaire les plus graves (trois dcmpDCMP ou plus). L’effet de la fluoration sur les dcmpDCMP a été observé dans toutes les catégories de revenu et de scolarité, mais semblait particulièrement prononcé au sein des ménages dont les niveaux de scolarité et de revenu étaient inférieurs. Les dcmpDCMP étaient démesurément concentrées dans les ménages à faible niveau de scolarité, mais ce résultat ne variait pas selon que leur eau était fluorée ou non.
Conclusion: L’effet principal de la fluoration sur les dcmpDCMP, et son effet bénéfique dans tous les groupes socioéconomiques, montrent qu’il s’agit d’une intervention en santé des populations à la fois bénéfique et justifiée. La fluoration était équitable au sens où ses avantages étaient particulièrement apparents dans les groupes dont le profil de santé buccodentaire était le pire, mais la nature des résultats devrait nous inciter à tenir compte des valeurs qui sous-tendent le verdict d’équité.
Mots clés: Canada, fluoration, santé buccodentaire, facteurs socioéconomiques
Footnotes
Acknowledgements: L. McLaren is supported by a Population Health Investigator Award from Alberta Innovates–Health Solutions. J.C.H. Emery is the Svare Professor in Health Economics at the University of Calgary.
Conflict of Interest: None to declare.
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