2. Annabella Boardman, BA

Peer support interventions are associated with improved patient-reported outcomes in diverse cancer populations, however structured peer support programs tailored to the needs of patients undergoing hematopoietic stem cell transplantation (HSCT) are lacking. This single-arm, proof-of-concept trial aimed to refine the Supporting Transplant Experiences with Peer Program (STEPP), a structured, five-session, manualized, phone-delivered peer support intervention focused on providing informational, emotional, and practical support for patients undergoing HSCT, with qualitative feedback from participants through semi-structured interviews. Adult patients with hematologic malignancies scheduled to undergo allogeneic or autologous HSCT were eligible to participate in the study approximately two weeks prior to their HSCT hospitalization. Participants received the STEPP intervention and participated in semi-structured qualitative exit interviews to provide feedback on the content of STEPP and to identify facilitators and barriers to engagement. Interviews were analyzed by two coders using framework guided rapid analysis. 25 of 37 eligible patients enrolled in the study and 20 completed all intervention sessions and exit interviews. Participants highlighted that discussions with peer mentor interventionists about the transplant journey was the most valuable aspect of STEPP. Positive experiences during the first intervention session facilitated patient engagement with the program. Barriers to engagement included logistical challenges in connecting with interventionists while experiencing physical symptoms during inpatient hospitalization and being paired with an interventionist who had a different cancer diagnosis and/or type of transplant. Patients undergoing HSCT reported positive experiences with STEPP prior to and during transplant hospitalization. Patients’ descriptions of barriers and facilitators to engagement with the STEPP intervention underscore the importance of patient input and programmatic structure in peer support interventions for this population. Insights from this proof-of-concept trial will be incorporated into future trials of STEPP to improve outcomes in HSCT recipients.