BACKGROUND: Upper extremity physical function is an essential health domain in the rehabilitation care for patients with upper limb amputation or absence. The PROMIS-9 UE Physical Function short form is a recently established instrument designed for individuals with upper limb amputation or absence. The instrument's responsiveness to changes after receiving a prosthesis has not been investigated. The current study aimed to evaluate the ability of the PROMIS-9 UE to detect changes in bimanual (two-handed) functional capacity after patients' receipt of a prosthesis. METHODOLOGY: A retrospective chart review was conducted on the longitudinal PROMIS-9 UE outcome measure scores completed between April 2016 and February 2024. Participants included individuals with an outcome collected before and after prosthesis receipt. RESULTS: The final sample size included 124 individuals (91 male, 33 female
43.4 ± 15.0 years old, 34.4 ± 103.0 months since amputation, and 62.9% injury etiology). Analyses found significant improvement across all patients in the PROMIS-9 UE scores from baseline to post prosthesis intervention (baseline: 25.3 ± 8.6, post: 29.5 ± 9.6
p <
0.001). The PROMIS-9 UE demonstrated a moderate responsiveness (Standardized Response Mean = 0.6) to prosthetic intervention. This was a directional change consistent with subjective patient reports of increased functionality. Furthermore, findings from the linear mixed model demonstrated significant responsiveness for the PROMIS-9 UE instrument to detect post-intervention changes after controlling for potential confounding effects (p <
0.001). CONCLUSIONS: These findings suggest the PROMIS-9 UE Physical Function instrument demonstrates moderate clinical utility in capturing patient progress following upper limb prosthesis intervention.