Social Economic Status Is Associated with a Lower Non-Relapse Mortality Rate and an Increased Overall Survival after Allogeneic Hematopoietic Stem Cell Transplantation

Introduction: Studies suggest that among cancer patients undergoing hematopoietic stem cell transplantation (HSCT), low socioeconomic status (SES) is associated with worse outcomes and higher mortality. Assessment of SES in these studies has generally been limited to a single dimension such as household income. We examined outcome after HSCT as a function of financial resources at the household and community level, and explored whether their association with survival reflected educational disparities.

Method: 383 patients underwent allogeneic HSCT (57% male; 82% White; mean age 50 y; 66% leukemia, 21% lymphoma). Pre-transplant, a social worker documented patients’ financial resources and educational background. Via census data, we derived median household income and high-school graduation rates at the census-block level. HSCT outcomes over six years were obtained from medical records.

Results: Controlling for demographics (age, gender, race, marital status) and medical factors (disease, pre-transplant chemotherapy, remission status, cell dose, donor-recipient CMV status, donor sex), greater pre-transplant financial resources were associated with longer survival (HR 1.55; p=0.007), as was higher median neighborhood income (HR 1.52; p=0.02). When entered simultaneously, higher financial resources (HR 1.45; p=0.03) and neighborhood income (HR 1.54, p=0.06) continued to predict longer survival. Adding educational attainment did not change the magnitude of these associations (financial resources HR 1.60; neighborhood income HR 1.90). Also, greater pre-transplant financial resources were associated with lower non-relapse mortality (NRM) than lower resources (HR 0.45; p=0.03).  

Conclusions: Greater financial resources are associated with lower non-relapse mortality and higher 2-year overall survival post-HSCT. This association is independent of educational attainment, suggesting that it reflects the influence of resources as opposed to knowledge or health literacy.