Clinical Validity of the Oral Frailty Five‐Item Checklist ( OF ‐5) for the Diagnosis of Oral Hypofunction

OBJECTIVE: This study aimed to clinically validate the Oral Frailty Five-item Checklist (OF-5) by clarifying the relationship between its score and the diagnosis of oral dysfunction, as well as its association with seven sub-items. BACKGROUND: Assessing oral frailty is important for preventing frailty in older adults. The recently developed OF-5 is anticipated as a convenient screening tool; however, its relationship with oral hypofunction, assessed through quantitative testing in dental clinics, has not been sufficiently verified. MATERIALS & METHODS: The study included 421 outpatients aged 65 years or older who underwent their first oral hypofunction test at a university dental hospital. Data on age, sex, OF-5 score, and oral hypofunction test values (oral hygiene, oral dryness, occlusal force, tongue-lip motor function, tongue pressure, masticatory function, and swallowing function) were extracted from medical records and analyzed using multivariate analysis. RESULTS: The age of the participants was 80.9 ± 6.5 (mean ± standard deviation) years, and 254 (60.3%) were female. Logistic regression analysis showed that the OF-5 score was significantly associated with the diagnosis of oral hypofunction (odds ratio: 2.54), with a cutoff value of 2 points. Multiple regression analysis showed significant associations between the OF-5 and all test components except oral hygiene. CONCLUSION: The OF-5 is a useful screening test for oral hypofunction, involving masticatory, swallowing, and tongue dysfunction and oral dryness. However, there is also a need for dental examination to identify poor oral hygiene, which cannot be detected using the OF-5 test.