6553 Background: Patients hospitalized for hematopoietic cell transplantation (HCT) may have prolonged length of stay (PLOS). The longitudinal effect of PLOS in this population on quality of life (QOL) and psychological distress is unknown. Methods: We conducted secondary analyses of data from three prospective studies of patients undergoing HCT (2011-2022) at three academic centers. We defined PLOS as ≥30 days for allogeneic and ≥21 days for autologous HCT from date of admission. We collected patient-reported outcomes (PROs) for QOL, anxiety, depression, and posttraumatic stress disorder (PTSD) symptoms at baseline, 2 weeks, 3 and 6 months post-HCT. We used multivariate logistic regression to assess the effect of change in PROs from baseline to week 2 on PLOS adjusting for age, transplant type, donor, and diagnosis. We then fit linear mixed effects models to characterize the trajectory of PROs by PLOS over time. Results: 593 patients (mean age 56 years) were included, the majority of whom were male (57%), white (82%), and underwent allogeneic HCT (52%). The most common diagnosis was acute leukemia (28%). Patients with PLOS (26%) were younger (57 [range 18-78 yrs], 53 [19-75 yrs], p = 0.002), had acute leukemia (26%, 34%, p = 0.001), received myeloablative conditioning (21%, 41%, p &lt; 0.001), and underwent allogeneic HCT (50%, 60%, p &lt; 0.001). At baseline, patients with PLOS had lower QOL (108, 102, p = 0.001) and more depression symptoms (4.4, 5.3, p = 0.02). There was no difference in baseline anxiety or PTSD symptoms. An increase in depression symptoms from baseline to week 2 was associated with greater odds of PLOS (adjusted OR = 1.08, p = 0.04). The table depicts longitudinal differences in PROs by PLOS. Compared to those without PLOS, patients with PLOS reported lower QOL (time*PLOS interaction, ∆ = -6.6, SE = 2.1, p = 0.001) and greater increase in depression symptoms (time*PLOS interaction, ∆ = 1.9, SE = 0.6, p &lt; 0.001) at week 2. Lower QOL in those with PLOS persisted through 6 months (Table). PLOS was associated with more re-admissions (0.8, 1.1, p = 0.02) and mortality (9%, 19%, p = 0.001) within 1 year of HCT. No difference was seen in rate of relapse and severe acute or chronic graft- versus-host disease. Conclusions: Patients with PLOS experienced worse QOL and increased psychological distress. Increase in depression symptoms from admission to week 2 may be an early indicator of PLOS and supports mental health screening during the index HCT hospitalization. Patients with PLOS may benefit from enhanced supportive care during and after HCT.[Table: see text]

Trajectories of patient-reported outcomes after prolonged stays for hematopoietic cell transplant.