Does the contribution of modifiable risk factors on oral health inequities differ by experience of negative life events among Indigenous Australian adults?

OBJECTIVE: Although the prevalence of poor self-rated oral health and experience of negative life events among Indigenous adults is high, the contribution of modifiable risk factors is unknown. We aimed to estimate the contribution of modifiable risk factors in poor self-rated oral health among Indigenous Australian adults with high and low experience of negative life events using decomposition analysis. METHODS: The study utilised a cross-sectional design, with data from a large convenience study of Indigenous adults in South Australia. Participants were stratified based on a median split of negative life events in the last 12 months. The outcome was the proportion of fair/poor self-rated oral health (SROH). Independent variables included experience of racism, sex, age, geographic location, car ownership, and time since last dental visit. RESULTS: Of the 1011 participants, the proportion with fair poor self-rated oral health was 33.5% (95% CI 30.5 to 36.4) and the proportion who had experienced 3+ negative life events in the past 12 months was 47.3% (95% CI 43.7 to 50.9). More than half the contribution in fair/poor self-rated oral health among Indigenous adults with a higher magnitude of negative life events was from experience of racism (55.3%, p<0.001), followed by residential location (19.9%), sex (9.7%) and car ownership (9.8%). CONCLUSIONS: The contributions of modifiable risk factors in poor self-rated oral health among Indigenous adults with different exposures to negative life events differed substantially. Targets to reduce racism will decrease oral health inequities for both groups, however Indigenous adults who have experienced substantial negative life events require additional focus on provision of culturally safe dental care.