Effects of Social Support Source and Effectiveness on Stress Buffering After Stem Cell Transplant

Background: This study used the social support effectiveness framework to examine whether effective social support buffered the relationship between stressful life events and distress among hematopoietic stem cell transplant (HSCT) survivors and whether that buffering effect depended on the type of caregiver who provided it (partner versus non-partner caregivers). Methods: A total of 275 HSCT survivors completed measures of the effectiveness of their caregiver’s support—social support effectiveness (SSE)—distress, and stressful life events. Hierarchical linear regression was used to analyze a three-way interaction between stressful life events, caregiver SSE, and caregiver type on distress. Results: After controlling for covariates, the three-way interaction of stressful life events, caregiver SSE, and caregiver type was significant (b = − 0.21, SE = 0.00, p < 0.001). Among partnered survivors, more stressful life events were associated with greater distress (B = 0.03, SE = 0.01, p = 0.045) when caregiver SSE was low. There was no association between stressful life events and distress when caregiver SSE was average (B = 0.01, SE = 0.01, p = 0.50) or high (B = − 0.01, SE = 0.02, p = 0.61). Among non-partnered survivors, there was a positive association between stressful life events and distress regardless of caregiver SSE. Conclusions: Average or highly effective caregiver support buffered effects of stressful life events on distress among partnered survivors. There was no evidence that support at any level of effectiveness buffered stressful life events among non-partnered survivors. Findings highlight the importance of measuring social support effectiveness and source of support among HSCT survivors.