Analysis of quality of life in breast cancer survivors using structural equation modelling: the role of spirituality, social support and psychological well-being

Background: To explore and characterize the inter-relationship between psychological well-being, spirituality, social support, comorbidity, demographic and lifestyle factors and quality of life (QoL). Methods: This cross-sectional study was conducted with 305 breast cancer survivors in northern Iran in 2017. The demographic and socio-economic data and physical activity were measured with a standard questionnaire. The standard European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30 QoL scale, a system-of-belief inventory questionnaire, the social support scale, the short form of the Hospital Anxiety and Depression Scale and the fatigue severity scale (FSS) were used in data collection. In structural equation modelling analysis, we used the maximum likelihood procedure to estimate the direct and indirect effects of relevant factors on QoL. Results: The median age (quartile 1 [Q1], quartile 3 [Q3]) of patients was 50 y (43, 55). The psychological factors designated by anxiety, depression and FSS had a negative significant direct effect on QoL (beta=-0.62). Spirituality has a positive direct effect (beta=0.089) but a negligible indirect effect (beta=0.020) on QoL, while the direct association of social support was almost negligible. Conclusions: The findings emphasized the unifying structure of the determinants of QoL and the mediating negative association of psychological factors with QoL. Thus the supportive education efforts should focus on improving psychological well-being along with standard treatment in breast cancer survivors.