Association of oral health factors related to oral function with mortality in older Japanese.

ABSTRACT

OBJECTIVE: To examine the effects of oral health factors related to oral function and their combination on mortality in older people. BACKGROUND: Recent studies have reported that oral factors, including oral function, are associated with mortality. MATERIALS AND METHODS: The participants were 4765 community-dwelling individuals aged 75 and 80 years. The follow-up period for survival or death was 3.5 years, and the date of death was defined based on data managed by the insurer. A Cox proportional hazard model was applied to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for mortality as dependent variables for oral health factors, including the number of teeth, swallowing disability, oral dryness and oral hygiene and the combinations of oral health factors as independent variables. RESULTS: In univariate analyses, all four oral health factors were significantly associated with mortality. After adjusting for age, sex, smoking, body mass index and medical history, and analysing the oral health factors separately, swallowing difficulty had the highest HR for mortality (adjusted HR, 2.12; 95% CI, 1.35-3.33). In the analysis using combinations of oral health factors as the independent variable, the participants with swallowing disability, oral dryness and poor oral hygiene had the highest HR for mortality (adjusted HR, 8.35; 95% CI, 3.45-21.08). CONCLUSION: Oral health factors related to oral function appear to be associated with mortality risk and an accumulation of oral health factors increases mortality risk among older people.