A Pilot Randomized Clinical Trial of a Peer Support Intervention for Hematopoietic Stem Cell Transplantation

Peer support has been associated with improved patient-reported outcomes (PROs), including reduced psychological distress, among patients undergoing hematopoietic stem cell transplantation. Structured interventions tailored for this population are limited. This study assessed the feasibility, acceptability, and preliminary effects of a scalable peer support intervention for reducing psychological distress and enhancing quality of life (QOL) post-HSCT. We conducted a pilot randomized clinical trial evaluating the Supporting Transplant Experiences with Peer Program (STEPP), a five-session, telephone-based intervention delivered by an HSCT survivor offering psychoeducation and coping strategies. Participants were recruited 1-2 weeks pre-HSCT admission and randomized to STEPP or usual care. Feasibility was defined as ≥60% enrollment and ≥60% completing ≥3 sessions. Acceptability was assessed using the Client Satisfaction Questionnaire (CSQ; ≥3/4 mean benchmark). PRO measures of anxiety, depression (HADS), post-traumatic stress (PCL-C), QOL (FACT-BMT), social support (SSEQ), and self-efficacy (CASE) were assessed pre-HSCT and at 30 and 60 days post-HSCT. Mixed-effects models explored STEPP's preliminary effects. We enrolled 77% (90/117) of eligible patients (STEPP n=45; usual care n=45). Twelve became ineligible due to HSCT cancellation or postponement. Among 78 active participants (mean age 58.9 years (SD=12.3); 57.7% women), all STEPP participants completed ≥3 sessions, and the mean CSQ score was 3.5. STEPP showed small-to-moderate improvements in Day 30 anxiety (d=-0.36) and Day 60 anxiety (d=-0.58), depression (d=-0.25), post-traumatic stress (d=-0.28), QOL (d=0.48), social support (d=0.36), and self-efficacy (d=0.46). STEPP exceeds feasibility and acceptability thresholds, showing promising psychosocial benefits warranting a fully powered multi-site efficacy trial. This study was preregistered on ClinicalTrials.gov (NCT06010017).