A study on the association between psychological capital and dyadic coping among lung cancer patients and their caregivers: an actor–partner interdependence model approach

Abstract

Background Lung cancer imposes heavy physical and psychological burdens on both patients and their caregivers. Increasing evidence suggests that dyadic coping—the joint process through which patient–caregiver pairs manage illness-related stress—plays a crucial role in emotional adjustment and relationship quality. Meanwhile, psychological capital (PsyCap), comprising optimism, hope, resilience, and self-efficacy, has been recognized as a key positive psychological resource that enhances adaptation to cancer-related challenges. However, research integrating these two constructs within the lung cancer context remains limited. Methods A cross-sectional study was conducted among 225 lung cancer patient–caregiver dyads recruited from hospitals in Chengdu between January and September 2025. Participants completed the Positive Psychological Capital Questionnaire (PPQ) and the Dyadic Coping Inventory (DCI). Pearson correlation analysis was used to examine bivariate associations, and the Actor–Partner Interdependence Model (APIM) was applied using AMOS 23.0 to explore actor and partner effects between PsyCap and dyadic coping. Results Significant positive correlations were found between patients’ and their caregivers’ PsyCap and dyadic coping (p < 0.01). APIM analysis revealed that both patients’ (β = 0.17, p = 0.013) and caregivers’ (β = 0.23, p < 0.001) PsyCap significantly predicted their own dyadic coping (actor effects). The caregiver’s partner effect on the patient’s coping was significant (β = 0.14, p = 0.037), while the reverse effect was not significant. The dyad conformed to a mixed interdependence pattern (k = 0.633, 95% CI [0.125, 1.169]). Conclusion Both patients’ and caregivers’ PsyCap were positively associated with dyadic coping. In the APIM, caregivers’ PsyCap showed a significant partner effect on patients’ dyadic coping, whereas the reverse partner path was not significant. Given the cross-sectional design, these findings should be interpreted as associations rather than causal effects. Longitudinal and intervention studies are needed to determine whether enhancing PsyCap can improve dyadic coping and related psychosocial outcomes in lung cancer dyads.