Mediating Effect of Upper Limb Use on the Relationship Between Upper Limb Performance and Activities of Daily Living: A Longitudinal Mediation Analysis

Introduction: Upper limb performance, frequency of upper limb use, and psychological factors are associated with activities of daily living (ADLs) after stroke. We performed a mediation analysis to investigate how the frequency of upper limb use and some psychological factors mediate the relationship between upper limb performance and ADLs. Methods: Twenty-two patients with stroke were included in this longitudinal study. We utilized the frequency of upper limb use outcome measures (amount of use and quality of motion of the motor activity log), psychological factors outcome measures (General Self-Efficacy Scale), upper limb performance outcome measures (Fugl-Meyer Assessment (FMA)), and ADLs outcome measure (Functional Independence Measure (FIM) motor subscale (M)). Mediation analysis with a bootstrap sampling procedure was used to assess the indirect effects. Results: Mediation analysis showed that the FMA, as measured by the FIM (M), had significant indirect effects on the amount of use (95% bootstrapped confidence interval (CI): 0.36-2.42) and quality of motion (95% bootstrapped CI: 0.06-1.88). The relationship between upper limb performance and ADLs was mediated by the frequency of upper limb use. Conclusion: Our findings suggest that improving the frequency of upper limb use may accelerate post-stroke recovery.