Can we perform allogeneic hematopoietic cell transplantation (HCT) safely in patients with limited social supports and substantial psychosocial complexity?

Abstract Introduction Allogeneic HCT is a potentially curative therapy for hematologic disorders. Despite its clinical benefits, disparities in access to HCT persist, in part due to stringent requirements at most transplant centers for 24/7 availability of a dedicated primary caregiver post-HCT. Additionally, transplant may be delayed or denied in patients with significant psychosocial challenges (e.g. mental health conditions, financial instability, lack of transportation). While these criteria are intended to promote safe post-transplant care, they may warrant re-evaluation given significant improvements in HCT safety. This study aims to characterize clinical outcomes of allogeneic HCT recipients with limited social support and high psychosocial complexity. Methods We conducted a retrospective cohort study of adult patients who underwent allogeneic HCT at a single academic center between July 2017 and December 2022, after institutional HCT eligibility criteria regarding caregiver support and psychosocial complexity were liberalized. Demographic, disease-related and transplant-related data, along with clinical outcomes including overall survival (OS), cause of death (relapse vs non-relapse mortality), and incidence of acute and chronic graft-versus-host disease (GVHD) were extracted from the electronic medical record. Psychosocial data were abstracted from the pre-transplant psychosocial assessment. Social support variables included identification of a caregiver, concerns about caregiver availability, co-residence, and caregiver relationship to the patient. Psychosocial risk factors included financial, transportation and housing insecurity; limited English proficiency; and history of substance use disorder, criminal justice involvement, mental health concerns, and treatment nonadherence. Composite scores were created for social support (caregiver-related variables only) and psychosocial complexity (a broader measure encompassing caregiver and psychosocial factors). We used the median split method to identify patients with limited social support and high psychosocial complexity. The primary outcome was OS; secondary outcomes included cause of death and incidence of acute and chronic GVHD. We estimated 12-month OS using the Kaplan-Meier method and used Cox proportional hazards regression to assess associations of social support and psychosocial complexity with OS, adjusting for demographic, disease and transplant characteristics. Adjusted logistic regression was used to assess associations with GVHD. Results Among 506 allogeneic HCT recipients (median age 62, 37% female, 17% nonwhite), 37.1% had limited social support. Nearly all patients (99.4%) identified a caregiver, but 91 (18%) did not live with their caregiver, and 172 (34%) identified a non-spouse as their caregiver. 25.5%, 13.6%, 9.7%, 4.7%, and 4.4% of participants screened positive for financial, mental health, substance use, transportation, and housing concerns, respectively. 12-month OS was similar between patients with limited vs. high social supports (79.2% vs. 81.7%). In multivariable Cox regression models, social support was not significantly associated with 12-month OS (HR 0.89, p = 0.20). In unadjusted analyses, 12-month OS was also similar in patients with high vs. low psychosocial complexity (77.2% vs 83.3%). In multivariable models, psychosocial complexity was modestly associated with lower 12-month OS (HR 1.09, 95% CI 1.01-1.19 p = 0.04). Non-relapse mortality accounted for a greater proportion of deaths in the high psychosocial complexity group (58.7% vs 42.2%, p = 0.034). Rates of acute and chronic GVHD did not differ significantly by social support or psychosocial complexity. Conclusion Limited social support alone was not associated with worse clinical outcomes post-HCT. Importantly, outcomes of HCT recipients with limited social support and substantial psychosocial complexity are encouraging, despite a modest association between psychosocial complexity with OS. These findings support the safety of HCT in patients with limited social support and psychosocial complexity and underscore the importance of increasing transplant referrals and revisiting standard transplant practice to improve HCT access for our most vulnerable populations.