Comparing inequalities in oral and general health: findings of the Canadian Health Measures Survey.

OBJECTIVE The aim of this study was to measure and compare the magnitude of income-related inequalities for oral and general health outcomes in Canada. METHODS Data for this study were from the 2007/09 Canadian Health Measures Survey (CHMS). The sample size consisted of 3,413 Canadians aged 18-79 (1,601 men and 1,812 women). Oral health indicators were the total number of decayed and missing teeth. General health was measured as obesity and high blood pressure. Socio-economic status was measured as equivalized household income. We used the concentration index (CI) to quantify income-related inequalities in these outcomes. Values for the concentration index range from -1 to +1 with negative (or positive) concentration indices showing that the outcome is more concentrated among the less well off (or among the better off). All statistical analyses were weight-adjusted for the complex survey design and standardized for age. RESULTS The concentration indices for oral health outcomes (decayed teeth = -0.25, missing teeth = -0.15) were greater than for general health outcomes (obesity = -0.05, high blood pressure = -0.04). The concentration indices for oral health outcomes, in contrast to general health outcomes, were statistically significant. CONCLUSION There were income-related inequalities for oral health outcomes with the disease concentrated more among the poor. Inequalities in oral health were greater than inequalities in general health. The variation in the funding of oral health care and general health care is likely to explain the differences in the magnitude of income-related inequalities for oral and general health.