(PS2-4) Cultural Difference in the Associations of Social Support with Quality of Life and Depression in Head and Neck Cancer Patients in the United States and China

Abstract Text:

Background: Social support is positively associated with mental health outcomes across different cultures. Previous literatures suggest cancer patients in the United States (U.S.) report higher social support than patients in China. However, the understanding of how the effect of social support on quality of life (QOL) and mental health among cancer patients differs by country remains limited. The purpose of this study was to examine 1) the differences in social support before starting radiotherapy (RT) for head and neck (H&N) cancer patients in China and the U.S. and 2) how country moderates the associations between pre-RT social support and 1-year post-RT QOL and depression.

Methods: A secondary analysis of a randomized controlled trial on head and neck cancer patients undergoing radiotherapy in the US (n = 126) and China (n = 153) was conducted. Participants completed the Medical Outcomes Study Social Support Scale (MOS-SSS), the Functional Assessment of Cancer Therapy-General (FACT-G), and the Center for Epidemiological Studies–Depression (CES-D) at enrollment (pre-RT) and 1-year post-RT. Simple moderation analyses were conducted using the PROCESS macro for SPSS with sex, income, pre-RT cancer symptom severity and xerostomia symptom severity, as well as pre-RT CES-D and FACT-G as covariates.

Results: U.S. participants reported greater pre-RT social support compared to patients in China (p < .001, Cohen’s d= .630). Further, U.S. participants reported higher pre-RT CES-D (p < .005, Cohen’s d=.72) and lower FACT-G (p < .001, Cohen’s d = .38) while reporting higher 1-year post-RT FACT-G (p < .001, Cohen’s d = .26). However, after adjusting for the relevant clinical and demographic characteristics, only the post-RT FACT-G between the two countries remained significant (p = .002). Country moderated the association between pre-RT social support and 1-year post-RT FACT-G (p=.005), such that social support was negatively associated with QOL for patients in China (beta = -.193, p= .019), but not for patients in the U.S. (beta = .165, p=.118). There were no significant main effects or interaction effect of country and MOS-SSS on post-RT CES-D (p’s > .50).

Conclusion: There were cultural differences on how pre-RT social support affects QOL, such that social support appeared detrimental for subsequent QOL for patients in China but not for those in the U.S. Understanding how culturally specific factors before cancer treatment are associated with post-treatment QOL could be beneficial in providing tailored support to cancer patients.