Adverse Social Determinants Independently Predict Outcomes After Allogeneic HSCT.

Allogeneic hematopoietic stem cell transplantation (HSCT) is a potentially curative treatment for hematologic diseases but remains associated with substantial morbidity and nonrelapse mortality (NRM). The impact of adverse social factors on transplant outcomes in universal healthcare settings remains incompletely defined. We conducted a retrospective single-center cohort study including 286 adults undergoing first allogeneic HSCT between 2012 and 2022. Three adverse social determinants were assessed at baseline: communication barriers, financial hardship, and living alone. Outcomes included overall survival (OS), NRM, graft-versus-host disease (GVHD), and cause-specific mortality. Multivariable models adjusted for age, HCT-CI, disease status, conditioning intensity, and donor type. The presence of ≥1 adverse social determinant was independently associated with inferior OS (HR 2.39, 95% CI: 1.62 to 3.53; P < .001) and higher NRM (HR 2.68, 95% CI: 1.74 to 4.12; P < .001). A dose-response relationship was observed with increasing numbers of adverse factors. Patients with adverse social determinants had higher cumulative incidence of acute grade II to IV GVHD (43% vs 30%, P = .005) and moderate/severe chronic GVHD (P = .002), as well as more infection-related deaths (28.6% vs 17.6%, P = .047). The magnitude of the association was comparable to established prognostic factors. Adverse social determinants are independently associated with inferior survival, increased GVHD risk, and higher NRM after allogeneic HSCT. Even within a universal healthcare system, social disadvantage significantly influences post-transplant outcomes and supports systematic identification of social risk and targeted supportive interventions.