A six-year cohort of 3,559 community-dwelling older adults in Japan linked oral frailty in 2016 to official long-term-care onset in 2022 and examined whether social frailty in 2019 partly mediated the association.
Key findings
- Over six years, 6.1% developed long-term-care dependency. Oral frailty had adjusted OR 1.47 (95% CI 1.01–2.17); pre-oral frailty had OR 1.39 (0.96–2.02), crossing 1. Social frailty was estimated to mediate 7–19% of the association, while complete-case estimates attenuated.
Why this matters globally
The findings support considering oral function and social participation together in healthy-ageing assessment, while intervention trials are needed to determine whether modifying either reduces care dependency.
Thai researcher contribution
Isi Susanti, jointly affiliated with Chulalongkorn and Tohoku universities, contributed to the analysis. This is Thai-affiliated collaboration, but the population and care system are Japanese.
Limitations to consider
As an observational cohort, residual confounding remains. Mediation requires strong no-unmeasured-confounding and temporal assumptions. Odds ratios are not risk ratios, missing data affected estimates, and Japanese definitions and certification may not transfer directly to Thailand.