Against the backdrop of China's rapidly aging population, elderly patients with geriatric comorbidities (defined as≥2 coexisting chronic diseases) and acute kidney injury in geriatric comorbidities (AKI-GC) face high risks and marked functional disabilities. Characterizing the disability profiles of this population provides an evidence base for personalized rehabilitation.

To evaluate and compare multidimensional functional disability in geriatric comorbidities and AKI-GC.

In this study, through a cross-sectional survey, 114 elderly patients with multimorbidity admitted to the Department of Nephrology, China Rehabilitation Research Center, from February to September 2025 were included (32 cases in AKI-GC group and 82 cases in non-AKI-GC group). A multidimensional assessment system was used to evaluate functional disability.

The results showed elderly patients with multimorbidity exhibited various degrees of functional disability, including a disability rate as high as 75.4% (86/114), anxiety 14.0% (16/114), depression 43.9% (50/114), sleep disorders 62.3% (71/114), malnutrition and its risk 57.0% (65/114), high risk of pressure ulcers 8.8% (10/114), frailty 40.6% (46/114), high fall risk 54.4% (62/114), and constipation 38.6% (44/114). Compared with the non-AKI-GC group, the AKI-GC group had significantly lower Activities of Daily Living (ADL) scores and a higher incidence of functional impairment, delirium, anxiety, depression, malnutrition and risk of malnutrition, high risk of pressure ulcers, frailty, and high risk of falls (P<0.05). The AKI-GC group presented higher Age-adjusted Charlson Comorbidity Index (ACCI), higher rates of abnormal sensory perception and communication, higher scores on the Geriatric Delirium Rating Scale, Self-rating Anxiety Scale (SAS), FRAIL scale, and Morse Fall Risk Assessment. Conversely, ADL scores, proportion of 5-time sit-to-stand≥16.7 s, Mini-mental State Examination (MMSE) scores, Mini Nutritional Assessment Short-Form (MNA-SF) scores, and Braden Pressure Ulcer Risk scores were significantly lower in the AKI-GC group (P<0.05).

Elderly patients with comorbidities have multidimensional functional disabilities, including disability, physical impairment, and psychological impairment. The onset of AKI exacerbates this process, impairing their nutrition, cognition, and emotional state. It is recommended that an interdisciplinary intervention system be established, focusing on nutritional support and rehabilitation interventions for psychological and physical functional disabilities, so as to improve clinical prognosis.