Investigation of the Relationship Between Physical Activity, Hope, Symptom Burden, and Health-Related Quality of Life in Lung Cancer via a Moderated Mediation Model.

[OBJECTIVE] To test a moderated mediation model linking physical activity (PA) to health-related quality of life (HRQoL) via symptom burden, with hope as a moderator, in lung cancer patients.

[METHODS] A cross-sectional study of 203 adults with stage III-IV lung cancer (205 enrolled, 2 excluded due to incomplete data) from a Chinese hospital analyzed PA (IPAQ-LF), symptom burden (MDASI-C), hope (HHI), and HRQoL (SF-8). Covariates were identified via univariable screening (p < 0.05). Spearman correlations, hierarchical regression, and PROCESS (Model 7; 5000 bootstraps) tested the moderated mediation model, with simple-slope probing at hope ± 1 SD.

[RESULTS] PA correlated with higher HRQoL (ρ = 0.53) and lower symptom burden (ρ = -0.48), while symptom burden negatively predicted HRQoL (ρ = -0.71) and hope positively predicted HRQoL (ρ = 0.59) and lower symptom burden (ρ = -0.56). Hierarchical models explained 57.7% of HRQoL variance, with PA (0.132), symptom burden (0.231), and hope (0.046) as key predictors. The PA-by-hope interaction was significant (B = 0.018, p = 0.008), with stronger PA effects on reduced symptom burden at low hope (B = -0.270, p < 0.001). The moderated mediation index was -0.017 (95% CI -0.032 to -0.003).

[CONCLUSIONS] PA improves HRQoL via reduced symptom burden, with this effect stronger at lower hope levels. Enhancing hope in interventions may maximize HRQoL benefits.