Oral Frailty Index-8 in the risk assessment of new-onset oral frailty and functional disability among community-dwelling older adults

Oral frailty is associated with the loss of oral function and increased care needs. We have previously developed an Oral Frailty Index (OFI-8) to identify older adults at risk of oral frailty. Herein, we aimed to examine whether OFI-8 scores are indicative of oral frailty or functional disability risk in community-dwelling older adults. A total of 2,011 individuals (51% women; mean age, 73.0 ± 5.5 years) participated in the 2012 baseline survey (last follow-up wave 2018). Oral frailty was assessed at each time point, based on tooth status, oral function, and other subjective measures. Functional disability was defined as long-term care certification granted during 2012–2019. The OFI-8 items were assessed at baseline. The prevalence and incidence rates of oral frailty at baseline and 6 years were 16% and 24%, respectively. The area under the receiver operating characteristic curve of OFI-8 was 0.88 with 95% confidence interval of 0.86–0.90 for oral frailty. The OFI-8 score of ≥4 points maximized the sum of sensitivity and specificity values. The corresponding positive rate, sensitivity, specificity, positive, and negative predictive values were 30%, 80%, 80%, 43%, and 95%, respectively, for baseline oral frailty. A 1-point increase in the OFI-8 score corresponded to a 1.3-fold increase in the risk of new-onset oral frailty and 1.1-fold increase in the risk of disability. OFI-8 may help identify individuals at risk of oral frailty and functional disability. It may also increase the awareness of oral care and facilitate its uptake.