Factors associated with cognitive frailty among community-dwelling older adults with olfactory impairment: a cross-sectional study in China

Background To explore the influencing factors of cognitive frailty among community-dwelling older adults with olfactory impairment. Methods Convenience sampling was adopted to recruit 419 older adults with olfactory impairment from three communities in Changchun City between March 2025 and March 2026. Data were collected using a general information questionnaire, Fried Frailty Phenotype Scale, Chinese version of the Montreal Cognitive Assessment, Family APGAR Index, Short Form Mini Nutritional Assessment, SARC-CalF, Short Geriatric Depression Scale, Oral Frailty Index-8, and Pittsburgh Sleep Quality Index. Multivariable Logistic regression analysis was applied to identify the influencing factors of cognitive frailty in community-dwelling older adults with olfactory impairment. Results Among 419 older adults with olfactory impairment, 102 had both physical frailty and mild cognitive impairment and were classified as having cognitive frailty (24.34%), while 116 had physical frailty alone, 61 had mild cognitive impairment alone, and 140 had neither condition. Significant between-group differences were found in age, hand grip strength, sex, marital status, sarcopenia screening result, nutritional status, oral frailty, and sleep quality ( p < 0.05). In the primary multivariable logistic regression model, higher hand grip strength was associated with lower odds of cognitive frailty, whereas unmarried status, risk of sarcopenia, risk of malnutrition, and high risk of oral frailty were associated with higher odds of cognitive frailty ( p < 0.05). Sensitivity analyses showed generally consistent associations for the other explanatory variables; however, hand grip strength was no longer significantly associated with CF after additional adjustment for age and sex. No evidence of multicollinearity was observed among variables retained in the primary model (VIF range: 1.078–1.132). The primary model demonstrated an AUC of 0.75 (95% CI: 0.69–0.80), with an optimal cut-off value of 0.195, sensitivity of 0.755, and specificity of 0.615. Conclusion The prevalence of cognitive frailty was relatively high among community-dwelling older adults with olfactory impairment, and several factors were associated with cognitive frailty. Therefore, community administrators should prioritize the screening and assessment of cognitive frailty among older adults with OI, particularly those with factors associated with higher odds of cognitive frailty. These findings may help identify high-risk individuals and inform the development of targeted health management strategies.