Frailty is associated with low physical activity and poor sleep quality in patients undergoing myeloablative allogeneic hematopoietic cell transplantation: a Fitbit® pilot study.

Introduction: Frailty, a multidimensional syndrome of reduced physiologic reserve, is associated with poorer outcomes following allogeneic hematopoietic cell transplantation (alloHCT), even among younger adults. This pilot study explores whether wearable sensor data reflecting physical activity and sleep are associated with pre-transplant frailty status in patients undergoing myeloablative alloHCT. Methods: Adults undergoing first myeloablative alloHCT at the University of Minnesota from June 2022 to January 2023 were enrolled and given Fitbit® Sense devices. Frailty was assessed pre-transplant using Fried Phenotype criteria. Activity and sleep data were collected from hospital admission to day +30 post-transplant. Descriptive and inferential statistics assessed differences across frailty phenotypes. Results: Nine patients were included: 2 not frail, 5 pre-frail, and 2 frail. Not frail patients demonstrated significantly higher daily steps and active minutes, and lower sedentary time compared to pre-frail and frail groups (all Conclusion: Pre-transplant frailty was associated with decreased physical activity and less restorative sleep during the peri-transplant period. These findings support further study of wearable data to guide personalized supportive care strategies in alloHCT recipients.