Oral health-related quality of life and total mortality: A prospective cohort study of Japanese dentists

[Objectives] To date, few studies of oral health-related quality of life (OHQOL) and mortality have been conducted, while data in the literature suggest that health-related quality of life is a predictor of mortality. We investigated whether OHQOL is predictive of total mortality in males and females. [Methods] We analyzed data in the Longitudinal Evaluation of Multi-phasic, Odontological, and Nutritional Associations in Dentists (LEMONADE) cohort study. A total of 10,114 Japanese dentists (mean age ± standard deviation, 52.4 ± 12.1 years) were included in the analysis. From 2001 through 2006, they completed the baseline questionnaire on lifestyle and health factors, including the number of teeth lost and the General Oral Health Assessment Index (GOHAI), to measure OHQOL. GOHAI scores lower than the Japanese norm were classified as having a poor OHQOL. Using Cox proportional hazard models, hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated after adjusting for age and other potential confounding factors. [Results] The mean follow-up period was 7.7 years. Males with poor OHQOL at baseline showed an increased total mortality risk. The multivariable HRs for males and females with GOHAI scores lower than the Japanese norm were 1.43 (95% CI, 1.16-1.76) and 1.26 (95% CI, 0.56-2.84), respectively, for total mortality referring to the higher GOHAI scorers. The risk for total mortality in male was little changed even after further adjustment for the number of teeth lost (HR, 1.40; 95% CI, 1.13-1.73). [Conclusion] Our findings suggest that OHQOL is independently associated with total mortality in males.