Hematopoietic Stem Cell Transplant Comorbidity Index (HCT-CI) Scores Correlates with Increased Readmissions and Days In Hospital In Patients Undergoing Myeloablative Hematopoietic Stem Cell Transplant

Hematopoietic Stem Cell Transplant Comorbidity Index (HCT-CI) Scores Correlates with Increased Readmissions and Days in Hospital in Patients Undergoing Myeloablative Hematopoietic Stem Cell Transplantation.

Ellen Szwed, Jack W. Hsu, Wei Hou, Randy A. Brown, Christopher R. Cogle, John W. Hiemenz, W Stratford May, Jan S. Moreb, Baldeep Wirk, John R. Wingard.

The hematopoietic stem cell transplant comorbidity index (HCT-CI) was developed to assess the impact of comorbidities in allogeneic stem cell transplant (AlloSCT) recipients. It has been shown to correlate with non-relapse mortality and overall survival in both the myeloablative, non-myeloablative (NMA), and reduced intensity (RIC) settings, regardless of graft source. However, the economic impact of allogeneic transplant in patients with comorbidities has not been assessed. We retrospectively analyzed 181 consecutive patients who underwent AlloSCT from an HLA identical sibling following either myleoablative (n= 109) or NMA/RIC (n=71) conditioning regimens between January 2001 and December 2008. The HCT-CI score was calculated according to the method of Sorror, et al. (Sorror ML, et al. Blood. 2005 106: 2912–2919). Median follow-up of the entire cohort was 2 years. As previously published, there was a statistically significant correlation between HCT-CI and both non-relapse mortality (HR = 1.147, p = 0.0170,) and overall survival (HR = 1.152, p=0.0001) at 2-years of 23% and 50% respectively. We found statistically significant correlations between the HCT-CI score and total number of hospital readmissions (mean = 1.92; r=0.192; p = 0.0098) and total days in hospital after initial discharge from hospital after stem cell infusion (mean = 22.4 days; r=0.156; p = 0.036). Interestingly, the correlation for number of hospital days did not become statistically significant until 180 days or greater after transplantation. There was no correlation between HCT-CI with graft source, relapse or graft-vs.-host disease. When we stratified the HCT-CI to either myeloablative (N=109) or NMA/RIC (N=71) conditioning regimens, the correlations between the HCT-CI and both non-relapse mortality and overall survival were still statistically significant. The differences in days of hospitalization remained statistically significant in the myeloablative setting, but not in the NMA/RIC setting. In conclusion, our analysis of AlloSCT recipients found a correlation between the HCT-CI and the number of readmissions and hospital length of stay for myeloablative but not NMA/RIC conditioning regimens, suggesting a higher HCT-CI score results in greater use of hospital resources and costs. The increase in resource utilization is greater after the immediate post-transplant period. Whether these conclusions also apply in other transplant settings will need to be investigated.

No relevant conflicts of interest to declare.