Suboptimal Oral Health, Multimorbidity, and Access to Dental Care

Introduction: Emerging studies on the links between suboptimal oral health and multimorbidity (MM), or the co-existence of multiple chronic conditions, have raised controversy as to whether enhancing access to dental care may mitigate MM in those with suboptimal oral health. In this study, we aim to assess the extent of the association between suboptimal oral health and MM and whether access to dental care can modify this association. Methods: We conducted a cross-sectional analysis using data from the Canadian Longitudinal Study on Aging (CLSA) (N = 44,815, 45 to 84 y old). Edentulism, self-reported oral health (SROH), and other oral health problems (e.g., toothache, bleeding gums) were used as indicators of suboptimal oral health. MM was defined according to the Public Health Agency of Canada as having 2 or more of the following chronic conditions: cancer, cardiovascular diseases, chronic respiratory diseases, diabetes, and mental illnesses. For robustness, we also used a cutoff of having 3 or more of these chronic conditions. Variables for access to dental care included (1) dental visits within the past year, (2) availability of dental insurance, and (3) cost barriers to dental care. We constructed robust Poisson regression models to estimate the association between suboptimal oral health and MM and then assessed the effect measure modification by indicators of access to dental care on a multiplicative scale. We also calculated the relative excess risk due to interaction for prevalence ratio (PR) on an additive scale. Results: Indicators of suboptimal oral health were significantly associated with MM (edentulism PR 1.17, 95% confidence interval [CI] 1.08, 1.27; poor SROH PR 1.44, 95% CI 1.33, 1.54; other oral health problems PR 1.52, 95% CI 1.44, 1.78). The magnitude of this association was higher in individuals who reported fewer dental visits within the past year, lacked dental insurance, and avoided dental care due to costs. Conclusion: The association between suboptimal oral health and MM may be exacerbated by barriers to accessing dental care. Policies aiming to enhance access to dental care may help mitigate MM in middle-aged and older Canadians with suboptimal oral health. Knowledge Transfer Statement: This study offers insights into the connection among suboptimal oral health, multimorbidity, and access to dental care factors in middle-aged and older Canadians. The findings can be of value for clinicians and policy makers aiming to enhance medical-dental integration and improve accessibility to dental care and to patients seeking information about the connections between oral health and chronic conditions. Implementation has the potential to enhance individual well-being and drive systemic improvements in health care.