Association Between Kihon Checklist Oral-Function Score and All-Cause Mortality in Community-Dwelling Older Adults.

BACKGROUND: We examined whether the Kihon Checklist (KCL) oral-function score (0-3), based on three self-reported symptoms (chewing difficulty, dysphagia, and xerostomia), was associated with all-cause mortality in community-dwelling older adults. METHODS: This cohort study included 52,789 adults aged ≥ 65 years who underwent municipal health checkups in Okayama City, Japan (fiscal year 2006-2007) with mortality follow-ups during December 2016. The KCL oral-function score (range 0-3) was the sum of the positive responses to the three oral-function items. Cox proportional hazards models were used to estimate adjusted hazard ratios (aHR). Secondary analysis examined the association of each symptom using separate and mutually adjusted models. RESULTS: Higher KCL oral-function scores were positively associated with increased all-cause mortality. In the fully adjusted model (n = 49,665), the aHRs (95% confidence interval [CI]) for scores 1, 2, and 3 were 1.09 (1.04-1.13), 1.26 (1.20-1.32), and 1.49 (1.38-1.60), respectively. Chewing difficulty (aHR 1.19 [95% CI 1.14-1.23]) and dysphagia (aHR 1.18 [95% CI 1.14-1.23]) were each independently associated with mortality, whereas xerostomia was not (aHR 1.02 [95% CI 0.98-1.06]). CONCLUSIONS: Higher KCL oral-function scores showed a positive association with all-cause mortality. Chewing difficulty and dysphagia were independently associated with mortality, whereas xerostomia was not. Symptom-based oral-function screening may help identify older adults at an elevated mortality risk.