Self-perceived burden and quality of life in patients with radiation-induced brain injury after radiotherapy for nasopharyngeal carcinoma: a cross-sectional study on the mediating role of stigma and the moderating role of sleep quality

BACKGROUND: Although self-perceived burden (SPB), stigma and sleep quality are associated with quality of life (QoL) in patients with radiation-induced brain injury (RBI) after radiotherapy for nasopharyngeal carcinoma (NPC), little is known about the mechanism underlying the relationship among these variables. The aim of this study was to examine the relationship among SPB, stigma, and QoL, and further explore how sleep quality may moderate the effect of stigma. METHODS: This cross-sectional study investigated 150 NPC patients with RBI who were recruited from an affiliated hospital of the university in Guangzhou, China. The participants completed several questionnaires, including a socio-demographic characteristics questionnaire, the Chinese version of the Self-Perceived Burden Scale (SPBS), the Social Impact Scale (SIS), the World Health Organization Quality of Life Instrument Short Form (WHOQOL-BREF), and the Pittsburgh Sleep Quality Index (PSQI). The mediation analysis and moderated mediation analysis were conducted using PROCESS macro Model 4 and Model 58 in SPSS 28, respectively. RESULTS: The results of mediation analysis showed that stigma had a significant indirect effect between self-perceived burden and quality of life (effect = -0.152, 95% CI = -0.223 to -0.032), and the direct effect of self-perceived burden on quality of life was not statistically significant (effect = -0.083, 95% CI = -0.300 to 0.134). In the moderated mediation analysis, the indirect effect of self-perceived burden on quality of life as mediated by stigma was apparent only among patients with poorer sleep quality (higher PSQI scores; effect = -0.115, 95% CI = -0.246 to -0.021). CONCLUSIONS: The findings suggest that stigma may function as a mechanism through which self-perceived burden is associated with quality of life in NPC patients with RBI, especially when patients suffer low sleep quality. Healthcare providers should pay attention to sleep quality and consider developing a supportive care intervention to improve patients' quality of life by incorporating effective strategies to reduce self-perceived burden and stigma for this population.