Inequalities in indigenous oral health: findings from Australia, New Zealand, and Canada

Abstract

The objective was to compare absolute differences in the prevalence of Indigenous-related inequalities in dental disease experience and self-rated oral health in Australia, Canada, and New Zealand. Data were sourced from national oral health surveys in Australia (2004 to 2006), Canada (2007 to 2009), and New Zealand (2009). Participants were aged ≥18 y. The authors measured age- and sex-adjusted inequalities by estimating absolute prevalence differences and their corresponding 95% confidence intervals (95% CIs). Clinical measures included the prevalence of untreated decayed teeth, missing teeth, and filled teeth; self-reported measures included the prevalence of "fair" or "poor" self-rated oral health. The overall pattern of Indigenous disadvantage was similar across all countries. The summary estimates for the adjusted prevalence differences were as follows: 16.5 (95% CI: 11.1 to 21.9) for decayed teeth (all countries combined), 18.2 (95% CI: 12.5 to 24.0) for missing teeth, 0.8 (95% CI: -1.9 to 3.5) for filled teeth, and 17.5 (95% CI: 11.3 to 23.6) for fair/poor self-rated oral health. The I(2) estimates were small for each outcome: 0.0% for decayed, missing, and filled teeth and 11.6% for fair/poor self-rated oral health. Irrespective of country, when compared with their non-Indigenous counterparts, Indigenous persons had more untreated dental caries and missing teeth, fewer teeth that had been restored (with the exception of Canada), and a higher proportion reporting fair/poor self-rated oral health. There were no discernible differences among the 3 countries.