A Composite Physical Performance Score for Predicting Discharge Functional Independence Measure motor score in Subacute Orthopedic Rehabilitation: A Retrospective Study.

Abstract

Objective To examine whether admission comfortable walking speed, Timed Up and Go test, and Berg Balance Scale add predictive value for discharge Functional Independence Measure motor score, and whether a composite score outperforms individual measures in older adults undergoing subacute orthopedic rehabilitation. Design Single-center retrospective cohort study of 158 patients aged ≥65 years admitted to a Japanese subacute rehabilitation ward. Linear regression compared a base model including common clinical factors with models adding walking speed, Timed Up and Go test, Berg Balance Scale, or an equal-weight composite score. Internal predictive performance was assessed using repeated 10-fold cross-validation. Results All three performance measures improved prediction beyond the base model. The composite score showed the best overall performance and the best cross-validated performance. The composite score remained independently associated with discharge Functional Independence Measure motor score (β=4.48, 95% confidence interval: 2.35-6.61), and adjusted mean score increased progressively across low, mid, and high score groups. Conclusions Admission mobility and balance measures provide incremental value for predicting discharge Functional Independence Measure motor score, and a simple composite score integrating single indicators may offer a practical, clinically interpretable approach for early prediction of discharge Functional Independence Measure motor score.