Does self-efficacy mediate the effect of oral health literacy on self-rated oral health in an Indigenous population?

Objectives: Mediation analyses are critical to understanding why behavioral interventions work. Health literacy is a known mediator between socio-economic factors, health behavior and oral health outcomes in various populations, explaining gradients in oral health status and outcomes. We explore whether self-efficacy (SE) mediates the association between oral health literacy (OHL) and self-rated oral health (SROH) in an Indigenous population. Methods: Cross-sectional data collected from 278 rural-dwelling Indigenous Australians evaluated OHL, SE, SROH, socio-demographic and behavioral characteristics. OHL was measured using a validated OHL scale (HeLD-14), SE was measured using a validated SE scale and SROH was measured using a global, one-item statement. Theoretically-driven multivariable models, adjusted for age, sex, income, education, and dental service use estimated the prevalence ratios (PR) and 95 percent confidence intervals for poor SROH. Results: The overall prevalence of poor SROH was 78.8 percent. The prevalence of low OHL was 46.0 percent, while the prevalence of low SE was 56.8 percent. Analysis showed a significant main effect of SE (PR = 2.5, 95 percent CI 1.3–4.6). SE attenuated the effects of OHL on poor SROH (from PR = 2.4 to PR = 2.0), supporting its associated role in the Indigenous population under study. Sobel and bootstrap testing confirmed the significance of the mediating effect (z = 2.2, SE 0.30, P < 0.05) and 95 percent CI (0.11–0.07) (P < 0.05) respectively. Conclusions: Given that SE is a construct amenable to change, our results suggest that interventions that aim to improve SE may have positive impacts on SROH among this vulnerable population.