Risk factors for readmission after allogeneic hematopoietic stem cell transplantation and impact on overall survival.

Patients treated with allogeneic hematopoietic stem cell transplantation (HSCT) are presumed to be at high risk for hospital readmission. The objective of this study was to identify the incidence and associated risk factors for readmissions in allogeneic HSCT patients and to evaluate the effect of readmissions on overall survival. In this retrospective review, we included 1141 HSCT patients (503 patients receiving a myeloablative [MAC] HSCT and 638 a reduced-intensity conditioning [RIC] HSCT). We measured rates of readmission at 30 days after discharge from HSCT and by day +100 after HSCT. Reasons for readmission, risk factors for readmission, and effect on overall survival were assessed. In the MAC group, 130 of 459 (28.3%) patients were readmitted within 30 days of discharge and 195 of 456 (42.8%) patients by day 100. In the RIC group, 105 of 600 (17.5%) patients were readmitted within 30 days of discharge and 185 of 595 (31.1%) patients by day 100. There were significantly more readmissions in the MAC group at both the 30-day (P < .001) and day +100 time points (P < .001). The most frequent reason for readmission was infection (28.2% in MAC group, 27.3% in RIC group). The occurrence of infection during the index admission was the only risk factor significant in both groups at both time points in the multivariable regression analysis. Readmission was significantly associated with decreased overall survival in both groups and at both time points. MAC patients are readmitted significantly more than RIC patients. Infection is the most common cause of readmission after HSCT and the occurrence of infection during the index transplantation admission is a significant risk factor for readmission. Readmission within 30 days of discharge and by day +100 after transplantation was a significant risk factor for a lower 5-year overall survival rate in both groups.