Social support as a buffer to the psychological impact of stressful life events in women with breast cancer

BACKGROUND. Three theoretical models by which social support may influence the impact of stressful life events on cancer patients' psychological state were tested: 1) the additive model, in which social support and stressful life events each directly influence cancer patients' adjustment, irrespecti ve of the magnitude of the other; 2) the buffering hypothesis, in which str essful events occurring in the presence of social support should produce le ss distress than if they occur in its absence; and 3) both additive and buf fering models. METHODS. One hundred seventy-nine patients who had Stage II breast cancer ( median age, 56 yrs; 68%, disease free), treated a mean of 6.8 years since e ntry to Cancer and Leukemia Group B (CALGB) 8541, were interviewed by telep hone concerning their psychosocial adjustment. The following measures were used: Medical Outcome Study Social Support Survey (MOS-SSS), Life Experienc e Survey (LES) a measure of stressful life events within the past 12 months , European Organization for Research on the Treatment of Cancer (EORTC QLQ- C30) a measure of quality of life, Mental Health Inventory (MHI), and the S ystems of Belief Inventory (SBI) a measure of spiritual and religious invol vement. RESULTS. Hierarchical regression analyses revealed that less than excellent levels of social support (P < 0.01), greater negative impact of LES fatefu l life events (e.g., death of family member) (P < 0.05), personal illness o r injury (P < 0.05), and all other negative life events in the past year (< 4; P < 0.01) were significant predictors of greater MHI psychological dist ress, in addition to being divorced or separated (P < 0.001), and more rece ntly treated for cancer on CALGB 8541 (P < 0.05). The interaction of LES sc ores with MOS-SSS or SBI social support, used to test the buffering hypothe sis, did not significantly improve the prediction of MHI psyche logical dis tress. CONCLUSIONS. The results supported the additive model, with both stressful life events and social support independently and significantly affecting pa tients' emotional state. However, the level of social support needed to be very high to reduce the likelihood of severe psychological distress. (C) 20 01 American Cancer Society.