Predictors and Impact Of 30-Day Readmissions On Patient Outcomes and Healthcare Costs After Allogeneic Hematopoietic Cell Transplantation
Authors: Kanate Abraham Sebastian , Rauenzahn Sherri , Leadmon Sonia , Truong Quoc V. , Cumpston Aaron , Goff Londia , Evans Kim , Zhang Jianjun , Wen Sijin , Craig Michael , Hamadani Mehdi 
Published: October 2019

Abstract
Readmission within 30 days of hospital discharge has recently become an important topic of discussion and a measure of quality of care. Factors influencing 30-day readmissions and its impact on patient related outcomes are diverse. Allogeneic hematopoietic cell transplantation (allo-HCT) presents a unique medical setting that may be associated with higher readmission rates. We analyzed factors affecting 30-day readmissions, its impact on patient related outcomes and health care costs in allo-HCT patients.
The study group included 91 consecutive patients with hematological malignancies who underwent related (n=44) or unrelated donor (n=47), peripheral blood allo-HCT after conditioning with fludarabine and busulfan +/- thymoglobulin. Subjects were divided into 2 groups; readmission (R-gp), n=35 if they were readmitted within 30 days of hospital discharge after the index hospitalization for a planned allo-HCT, or to no readmission (NR-gp), n=56. The baseline characteristics did not differ between the 2 groups (Table 1). Overall 38% (n=35) required readmission with a median time to readmission of 14 days (range, 1-29). Causes for readmission included documented infections (n=12), cardio-pulmonary complications (n=10), fever (n=6), gastrointestinal disorders (n=4), and graft-versus-host disease (n=3). Median length of stay was 3 days (range, 1-34). In multivariate analysis only documented infection during the index admission predicted 30-day readmission, OR 5.24; 95% CI 1.42-19.32; p=0.01. Caregiver type (spouse vs. others); and number of caregivers (1 vs. >1) did not influence readmission. With a median follow up of 1 year for surviving patients, the estimated overall survival (OS) was 58% and 67% in the R-gp and NR-gp respectively, OR 1.07, 95% CI 0.55-2.06, p=0.85. The 1-yr non-relapse mortality (NRM) in R-gp and NR-gp was 74% and 84% respectively, OR 1.13, 95% CI 0.42-3.03, p=0.80. The median post-transplant hospital charges (inpatient + outpatient) in the R-gp and NR-gp were 85,115.45 USD (mean 93,925.26, range 32,014.86-242,519.35) and 45,083.09 USD (mean 69,142.6, range 10,714.78-485,456.08), p=0.0002.
In conclusion, except for infections during the index admission, no other baseline demographic, social, disease or treatment related factors influenced 30-day readmissions after allo-HCT. 30-day readmission status did not adversely affect OS or NRM, but it significantly increased the 100-day hospital charges. Acknowledging the limitation of our study included its retrospective nature and small sample size, we conclude that 30-day readmission status does not portend poor post transplant outcomes. However, it is associated with higher health care costs.Table 1Baseline Patient CharacteristicsReadmission (n=35)Not Readmitted (n=56)P-ValueMedian age (range)56 (17-72)54 (22-68)0.23Male (%)21 (60)34 (61)0.99Malignancy type, n (%)0.93ALL/AML/MDS23 (65.7)39 (70)CLL/CML2 (5.7)3 (5)Hodgkin/NHL/Others10 (28.6)14 (25)Disease risk, n (%)0.18Low16 (45.7)24 (43)Intermediate3 (8.6)13 (23)High16 (45.7)19 (34)Disease status, n (%)0.49Chemosensitive23 (66)41 (73)Resistant12 (34)15 (27)Prior number of therapy, median (range)2 (1-6)2 (0-6)0.65Prior radiation therapy, n (%)2 (6)8 (14)0.31Prior autologous transplantation, n (%)2 (6)6 (11)0.71KPS, median (range)80 (60-100)85 (70-100)0.44HCT-CI, median (range)2 (0-7)1 (0-5)0.31Patients receiving ATG, n (%)23 (66)31 (55)0.38Donor type, n (%)Unrelated19 (54)28 (50)0.83Related16 (46)28 (50)HLA mismatch, n (%) §0.99Allele level1 (2)3 (5)Antigen level1 (2)1 (2)Infused CD34 cell dose, median (range) ¶6.5 (2.7-12.8)6.5 (1.8-15.1)0.98Infused CD3 cell dose, median (range) Ŧ31.3 (9.6-58.5)32.4 (11.5-94.5)0.48GVHD prophylaxis, n (%)0.83MTX + calcineurine inhibitor22 (63)33 (59)MMF + calcineurine inhibitor13 (37)23 (41)*High resolution HLA typing at the allele level for A, B, C and DRB-1 for all patients.¶Cell dose x 106/kg patient body weightŦCell dose x 107/kg patient body weight

Disclosures:
No relevant conflicts of interest to declare.