Can N-terminal pro-B-type natriuretic peptide concentration on admission predict the functional independence measure at discharge in patients aged 75 years or older with postoperative proximal femur fracture?

[Purpose] To examine whether functional independence measure scores and effectiveness at discharge can be predicted using N-terminal pro-B-type natriuretic peptide concentrations at admission in postoperative patients aged ≥75 years with proximal femur fractures. [Participants and Methods] This study included 35 patients who were admitted for rehabilitation after proximal femur fracture surgery between April 1, 2020 and September 20, 2023 and were discharged by November 30, 2023. The primary outcomes were the functional independence measure scores and effectiveness at discharge. The explanatory variables analyzed using multiple regression included demographic data; N-terminal pro-B-type natriuretic peptide concentration, estimated glomerular filtration rate, and geriatric nutritional risk index at admission; functional ambulation categories before injury; and motor, cognitive, and total functional independence measure scores at admission. [Results] The motor functional independence measure score at admission and N-terminal pro-B-type natriuretic peptide concentration were significant explanatory variables for the motor functional independence measure score at discharge. The N-terminal pro-B-type natriuretic peptide concentration was a significant explanatory variable in total and motor functional independence effectiveness. [Conclusion] This study, which excluded cognitively impaired patients and focused on individuals aged ≥75 years, suggests that N-terminal pro-B-type natriuretic peptide concentration at admission affects the functional independence measure scores and effectiveness at discharge.