Association of the Oral Frailty Index-8 With the Diagnosis and Results of Oral Hypofunction Testing

Oral frailty is associated with physical frailty and the risk of requiring nursing care and death in older people. The Oral Frailty Index-8 (OFI-8) was developed for self-assessment of oral frailty, assuming that high-risk patients will visit a dentist for oral hypofunction tests. However, the screening utility of the OFI-8 for oral hypofunction and the relationship between them remain unclear.

In this study, we aimed to elucidate the relationship between the OFI-8 and the diagnosis and results of oral hypofunction tests through a cross-sectional survey of older outpatients visiting dental clinics.

Outpatients (n = 120) who underwent diagnostic tests for oral hypofunction were enrolled. The survey items encompassed age, sex, oral hypofunction test results and the OFI-8 score. The relationships between oral hypofunction diagnosis and the OFI-8 score and between the oral hypofunction test and OFI-8 scores were analysed.

Binomial logistic regression analysis showed that the higher the total OFI-8 score was, the more likely the diagnosis of oral hypofunction (odds ratio = 1.76) was. Receiver operating characteristic curve analysis identified a cut-off OFI-8 score of 3 for detecting oral hypofunction (area under the curve = 0.77). Multiple regression analysis showed that oral dryness, occlusal force, number of teeth, masticatory function, swallowing function and number of items with functional decline were significantly associated with high OFI-8 scores. Oral hygiene, tongue-lip motor function and tongue pressure were less sensitive to the OFI-8.

The OFI-8 is useful for screening oral hypofunction, exhibiting considerable potential effectiveness in detecting oral dryness, occlusal, masticatory and swallowing dysfunctions.