The architecture of quality of life after stroke: a network comparison of mild-to-moderate versus severe functional impairment

Abstract

Background Health-related quality of life (HRQoL) after stroke is multidimensional, yet conventional analyses often overlook the complex interactions among its domains and how these might differ by functional status. Objective This study aimed to model and compare the network architecture of HRQoL between stroke survivors with mild-to-moderate versus severe functional dependence. Methods In this multi-center cross-sectional study, 451 inpatients were assessed using the Stroke-Specific Quality of Life (SS-QOL) scale across 12 domains. Participants were stratified into a Mild–Moderate group (Barthel Index, BI > 40; n = 259) and a Severe group (BI ≤ 40; n = 192). Polychoric correlations were used to account for the ordinal nature of the SS-QOL items. Strength centrality and bridge expected influence (based on a priori communities: Physical, Psychological, Social, General) were calculated to identify hubs and bridges. Network stability was assessed via bootstrap analysis, and a Network Comparison Test (NCT) was performed to compare global strength and network structure between groups. Results Although network structure did not differ significantly between groups (p = 0.928), the severe dependence group showed significantly higher global strength (p = 0.021), suggesting a more densely connected HRQoL network. In the Mild–Moderate group, strength centrality was highest for Self-Care (S7; 1.209) and Social Roles (S8; 1.014). In the Severe group, strength centrality was highest for Upper Extremity Function (S10; 1.124) and Thinking (S9; 1.031). Bridge expected influence was highest for Thinking (S9; 0.694) in the mild–moderate group and for Language (S3; 0.722) and Thinking (S9; 0.701) in the severe group. Network stability was acceptable in both groups (CS-coefficients: 0.595 and 0.438 for strength centrality). Conclusion The fundamental architecture of post-stroke HRQoL differs across levels of functional dependence. These findings support a precision rehabilitation framework: one targeting the synergy between physical functions in milder cases, and another focused on supporting cognitive integrity and social adaptation in severe disability.