A novel, structured peer support intervention (STEPP) for patients undergoing hematopoietic stem cell transplantation: A pilot randomized clinical trial

Abstract Background: Peer support has been associated with improved patient-reported outcomes (PROs), including reduced psychological distress, among patients undergoing hematopoietic stem cell transplantation (HSCT). However, structured peer support interventions tailored for this population are limited, representing a gap in patient-centered psychosocial care. This study assessed the feasibility, acceptability, and preliminary effects of a brief, structured, scalable peer support intervention for reducing psychological distress and enhancing quality of life (QOL) post-HSCT. Patients and Methods: We conducted a pilot randomized clinical trial (RCT) to evaluate the Supporting Transplant Experiences with Peer Program (STEPP), a 5-session, telephone-based intervention delivered by an HSCT survivor that provides psychoeducation and evidence-based coping strategies, including approach-oriented coping strategies. Participants were randomized to STEPP or usual care. Feasibility was determined using a prioribenchmarks of ≥60% enrollment and ≥60% completion of at least 3 sessions. Acceptability was assessed at intervention completion using the Client Satisfaction Questionnaire (CSQ), with a≥3/4 mean score benchmark for acceptability, with higher scores indicating greater satisfaction. PRO measures of anxiety and depressive symptoms (HADS), post-traumatic stress symptoms (PCL-C), QOL (FACT-BMT), social support (SSEQ), and self-efficacy for managing cancer (CASE) were assessed pre-HSCT and at 30 and 60 days post-HSCT. Mixed effect models explored STEPP's preliminary effects on these PROs. Results: We enrolled 77% (90/117) of eligible patients (STEPP, n=45; usual care, n=45); however, 12 participants became ineligible after enrollment, primarily due to transplant postponement, leaving 78 active participants (STEPP, n=38; usual care, n=40; mean age 58.9 years (SD=12.3), 57.7% women). All STEPP participants completed at least 3 out of 5 sessions. The mean CSQ item response was 3.5. Compared to usual care, STEPP showed small to moderate effect size improvements in anxiety (d=0.36) by Day 30 and anxiety (d=0.57), depression (d=0.25), post-traumatic stress (d=0.27), QOL (d=0.47), social support (d=0.38), and self-efficacy (d=0.46) by Day 60 post-HSCT. Conclusions: The STEPP intervention exceeded feasibility and acceptability thresholds and showed promising signals for psychological distress, QOL, social support, and self-efficacy for managing cancer by 60 days post-HSCT. A fully powered multi-site efficacy RCT is needed to evaluate STEPP's effects on patient symptoms.