Abstract
BACKGROUND: Oral health decline in later life is linked to poor nutrition, lower quality of life, and higher morbidity. Frailty, operationalized by the Frailty Index (FI), summarizes cumulative health deficits. Whether frailty predicts subsequent deterioration in oral health remains uncertain. METHODS: We analyzed data from the English Longitudinal Study of Ageing (ELSA). Participants aged ≥ 50 years who rated their oral health as “good” at wave 8 and had follow-up at wave 9 were included (n = 5,526). Oral-health decline was defined as a transition from “good” at baseline to “not good” at follow-up. FI was examined continuously and by quartiles. Cox proportional hazards models with progressive adjustment estimated hazard ratios (HRs) and 95% CIs. Linear trend across FI quartiles, restricted cubic splines, and prespecified subgroup/interaction analyses were conducted. RESULTS: Higher frailty predicted faster oral-health deterioration. In the fully adjusted model, each 1-point increase in FI was associated with a 3% higher hazard (HR = 1.03, 95% CI: 1.02–1.04; P < 0.001). Compared with the lowest FI quartile, HRs were 1.33 (95% CI: 1.00–1.77), 1.58 (1.16–2.14), and 2.26 (2.02–3.70) for quartiles 2–4, respectively (P-trend < 0.001). Spline analyses supported an approximately linear dose–response. Associations were broadly consistent across subgroups defined by age, sex, smoking, drinking, marital status, hypertension, diabetes, COPD, cancer, and depression, with no material effect modification. CONCLUSION: In a national cohort of older adults in England, greater frailty was independently associated with higher risk of oral-health decline over two years. Integrating oral-health assessment and prevention into frailty screening and management may help mitigate deterioration.