Sex-Specific Associations Between Oral Function Impairment and Clinical Outcomes in Hospitalized Older Adults: A Retrospective Observational Study

Abstract

Purpose: Oral functional impairment is a critical factor influencing clinical outcomes in hospitalized older adults. Notably, sex disparities in oral health on clinical outcomes remain an often underappreciated aspect.This study aims to investigate the association between oral function, assessed using the bedside oral examination (BOE), and in-hospital mortality, with an emphasis on sex-specific differences. Patients and Methods: A retrospective cohort study was conducted involving 1,141 patients aged 65 years and older who were admitted to a medical center in Taiwan between 2018 and 2023. The BOE was a standardized clinical tool that evaluated eight domains of oral health, including swallowing, lips, tongue, saliva, mucous membranes, gingiva, teeth or dentures, and oral odor. Patients were classified into normal, moderate, or severe oral impairment groups. Cox proportional hazards models and Kaplan–Meier survival analysis were used to examine mortality risk, with results stratified by sex. Results: Overall, greater oral functional impairment was associated with higher in-hospital mortality and poorer physical, nutritional, and psychological status. In the sex-stratified analysis, severe oral impairment remained an independent predictor of mortality in male patients (hazard ratio 1.77, 95% confidence interval 1.05 to 2.99, p = 0.032), but not in female patients. Survival differences were statistically significant among men based on oral function levels, as shown by Kaplan–Meier curves (log-rank p = 0.014), while no significant difference was found among women (log-rank p = 0.376). Conclusion: Severe oral functional impairment significantly predicts in-hospital mortality among older men, but not women. These findings underscore the importance of sex-specific approaches to risk assessment and intervention. Incorporating oral health screening into routine geriatric care, especially for men, may enhance early identification of high-risk patients and inform targeted strategies to improve clinical outcomes. Further research is warranted to understand the mechanisms underlying these sex differences.