Background: Despite current improvement in supportive care, mortality after hematopoietic
stem cell transplantation remains high. Depending on the diagnosis, this procedure is indicated as
the frontline treatment Aim: Assess comorbidity index in predicting toxicity and mortality risk
among patient undergoing hematopoietic stem cell transplantation through: assess comorbidities of
patient's pre-hematopoietic stem cell transplantation, assess toxicity and mortality risk post
hematopoietic stem cell transplantation & assess the relation of pre-transplantation comorbidity
scores and post transplantation-related toxicity and mortality in patients undergoing hematopoietic
stem cell Transplantation. Study design: A descriptive retrospective design was utilized to conduct
this study. Subject: A purposive sample of (44) patients undergoing allogeneic hematopoietic stem
cell transplantation was recruited in this study. Setting: This study conducted at The Bone Marrow
Transplantation Unit in Nasser institute for research and treatment. Tools: Tool I. Patient structured
interview questionnaire, Tools II. The hematopoietic stem cell transplantation specific-comorbidity
index (HCT-CI) & Tools III Seattle Criteria for Organ Toxicity after Bone Marrow Transplantation.
Results: The study revealed that there was a positive Correlation between comorbidity, organ
toxicity and total mortality post bone marrow transplantation with p value 0.01. Conclusion:
Comorbidity index is an important tool to predict toxicity and mortality rate among patient
undergoing hematopoietic stem cell transplantation as there was a positive correlation between
patient's comorbidity (obesity, cerebrovascular disease, cardiac disease, infection, renal disease,
prior malignancy, hepatic disease and psychiatric disorder) and total toxicity and mortality post
bone marrow transplantation. Recommendations: Apply Comorbidity Index in predicting toxicity
and mortality risk among patient undergoing Hematopoietic Stem Cell Transplantation.