BackgroundSocial support plays an important role for health outcomes. Support for those living with chronic conditions may be particularly important for their health, and even for their survival. The role of support for the survival of cancer patients after receiving an allogeneic hematopoietic cell transplant (alloHCT) is understudied. To better understand the link between survival and support, as well as different sources and functions of support, we conducted two studies in alloHCT patients. First, we examined whether social support is related to survival (Study 1). Second, we examined who provides which support and which specific support-related functions and tasks are fulfilled by lay caregivers and healthcare professionals (Study 2).MethodsIn Study 1, we conducted a retrospective chart review of alloHCT patients (N = 173, 42.8% female, age: M = 49.88) and registered availability of a dedicated lay caregiver and survival. In Study 2, we prospectively followed patients after alloHCT (N = 28, 46.4% female, age: M = 53.97, 46.4% ethnic minority) from the same hospital, partly overlapping from Study 1, who shared their experiences of support from lay caregivers and healthcare providers in semi-structured in-depth interviews 3 to 6 months after their first hospital discharge.ResultsPatients with a dedicated caregiver had a higher probability of surviving to 100 days (86.7%) than patients without a caregiver (69.6%), OR = 2.84, p = 0.042. Study 2 demonstrated the importance of post-transplant support due to patients’ emotional needs and complex self-care regimen. The role of lay caregivers extended to many areas of patients’ daily lives, including support for attending doctor’s appointments, managing medications and financial tasks, physical distancing, and maintaining strict dietary requirements. Healthcare providers mainly fulfilled medical needs and provided informational support, while lay caregivers were the main source of emotional and practical support.ConclusionThe findings highlight the importance of studying support from lay caregivers as well as healthcare providers, to better understand how they work together to support patients’ adherence to recommended self-care and survival.