Frailty and Energy Intake Deficiency Reduce the Efficiency of Activities of Daily Living in Patients with Musculoskeletal Disorders: A Retrospective Cohort Study

<b>Background/Objective:</b> This study aimed to investigate the relationship between rehabilitation effectiveness (RE) and pre-admission Clinical Frailty Scale (CFS) scores and energy intake. <b>Methods:</b> This retrospective observational study included 735 patients (81 ± 10 years; male: 27.5%) with musculoskeletal disorders discharged from convalescent rehabilitation wards between April 2018 and April 2024. The patients were classified into four groups based on their CFS scores (non-frail, CFS 1-3; frail, CFS ≥ 4) and rate of energy intake (energy-sufficient vs. energy-deficient). Group comparisons of RE were conducted, and the relationships between the CFS score, energy intake, and RE were analyzed. <b>Results:</b> The RE was significantly lower in the frail/energy-deficient group (53.6 [41.9-78.1]) than in the non-frail/energy-sufficient (78.5 [61.8-90.7]), non-frail/energy-deficient (70.6 [53.4-87.4]), and frail/energy-sufficient (59.9 [41.9-78.1]) groups. Additionally, the frail/energy-sufficient group had significantly lower RE scores than the non-frail/energy-sufficient and non-frail/energy-deficient groups. A multiple linear regression analysis revealed that age, male sex, CFS score, energy intake, handgrip strength, Functional Oral Intake Scale score, Mini Nutritional Assessment-Short Form score, B-type natriuretic peptide, and creatinine were significantly associated with the RE. <b>Conclusions:</b> Both frailty and inadequate energy intake reduce the rate of improvement in activities of daily living in patients with musculoskeletal diseases.