Socioeconomic Inequalities and Oral Health in Canada and United States

Objectives: To describe population-representative estimates of socioeconomic inequalities in oral health among adults in Canada and the US over the last 30 years. Methods: We analyzed data from nationally representative surveys in Canada and the US; Nutrition Canada National Survey (1970-1972), Canadian Health Measures Survey (2007-2009), The First National Health and Nutrition Examination Survey (1971-1974) and National Health and Nutrition Examination Survey (2007-2008). Oral health outcomes examined comparably across all four surveys were prevalence of edentulism, proportion of individuals having at least one untreated decayed tooth and proportion of individuals having at least one filled tooth. Sociodemographic indicators included in our analysis were nativity (based on place of birth), education (high school and less or greater than high school) and income (low, medium or high). We adjusted income for inflation and we recoded social categories based on information available from the four surveys to make the comparison on a common scale. Data were age adjusted and survey weights were used to account for the complex survey design in making population inferences. Results: In general, oral health outcomes have improved for adults in both Canada and the US. In the 1970s, compared to the US, Canada had a higher prevalence of edentulism and dental decay and lower prevalence of filled teeth. This was also combined with a more pronounced social inequality gradient among nativity, education and income groups. Over time, both countries demonstrated an improvement in the prevalence of edentulism, dental decay and filled teeth with a decline in absolute socioeconomic inequalities. In the recent period, Canada and the US demonstrate similar disparity gradient pattern. Conclusion: Although socioeconomic inequalities in adults' oral health have improved in both Canada and the US, this improvement was more pronounced in Canada.