The Mediating Effect of Trunk Impairment on Quality of Life in Subacute Stroke Survivors

Objective: This study aimed to clarify the determinants (e.g., age, sex, education level, stroke type, and disease severity) of trunk impairment and quality of life (QoL) among stroke survivors and to examine whether trunk performance mediates the relationship between the National Institutes of Health Stroke Scale (NIHSS) and QoL. Method: A quantitative, correlational design was employed and conducted between August 2023 and March 2025. Participants were stroke survivors recruited from the rehabilitation wards of three hospitals in Taiwan. The questionnaire included four measures: demographic data (including stroke type), the NIHSS (disease severity), the Trunk Impairment Scale (trunk performance), and the Stroke Impact Scale (QoL). Structural equation modeling with partial least squares (PLS-SEM) was used to examine the relationships among the variables. Model fit was assessed using the normed fit index (> 0.90) and the standardized root-mean-square residual (< 0.08). Results: A total of 160 stroke survivors participated, with a mean age of 63.04 years (SD = 13.29). Age (β = −0.145, p = 0.020) and disease severity (β = −0.60, p < 0.001) were significantly and negatively associated with trunk performance. Disease severity was also significantly and negatively associated with QoL (β = −0.196, p < 0.001). Trunk performance partially mediated the relationship between disease severity and QoL (β = 0.647, p < 0.001). Ischemic stroke type was significantly and positively associated with QoL (β = 0.194, p = 0.049). Collectively, disease severity, trunk performance, and ischemic stroke type explained 64.0% of the variance in QoL (Q2 = 0.358, f2 = 0.807), indicating strong predictive power. Conclusion: Stroke survivors with greater disease severity, poorer trunk performance, and hemorrhagic stroke experience lower QoL. Older individuals are more likely to exhibit trunk impairment. Notably, greater disease severity may lead to poorer trunk performance, which in turn contributes to reduced QoL. Rehabilitation interventions should focus on strengthening trunk control and stability in stroke survivors.