A Simple Feeding Efficiency Test as a Screening Tool for Oral Function in Older Adults: A Cross-Sectional Study

Background Aspiration pneumonia is a major public health concern among older adults in aging societies. Although various oral function tests are available, most assess only a single aspect of oral function and require specialized equipment. Therefore, a simple and comprehensive screening indicator applicable in routine clinical practice is needed. This study aimed to evaluate the potential usefulness of a newly developed feeding efficiency (FE) test as a screening indicator of oral function in older adults. Methods This cross-sectional study included older adults aged ≥65 years who visited a dental clinic and provided informed consent. Data collected included age, sex, oral hygiene status (Oral Hygiene Index-Debris Index (OHI-DI)), salivary flow rate, maximum tongue pressure, oral diadochokinesis (ODK) (/pa/, /ta/, /ka/), number of remaining teeth, and functional tooth units of natural teeth and artificial teeth on implant-supported or fixed pontics (nif-FTU). FE was assessed using a sausage-based feeding task and was defined as the amount of food ingested (g) divided by the number of chewing cycles required to complete swallowing, reflecting FE during habitual eating. Associations between FE, oral function measures, and salivary bacterial counts were analyzed. Results A total of 43 participants (16 males and 27 females; mean age 73.7 years) were included. FE values ranged from 5.6 to 67.7 (mean±SD: 24.4±14.8). Participants with nif-FTU ≥6 demonstrated significantly higher FE values than those with nif-FTU <6 (<i>p</i>=0.023). No significant associations were observed between salivary bacterial counts and tongue pressure, ODK, or nif-FTU. In contrast, salivary bacterial counts were significantly higher in participants with FE <15 (<i>p</i>=0.045). Conclusions The FE test may capture aspects of overall oral function during the feeding process that are not fully reflected by conventional oral function measures. Low FE values were associated with increased salivary bacterial counts, suggesting potential relevance to aspiration pneumonia risk. The FE test may have potential as a simple and practical screening indicator for oral functional decline in older adults; however, further studies involving frailer populations and longitudinal designs are warranted to validate its clinical applicability.