Barriers to Allogenic Hematopoietic Stem Cell Transplantation in MDS: Exploring the Role of Age, Race and Insurance - an NIS Database Study from 2016-2020
Authors: Sanjeevi Aditya , Jose Domench Daniel Idoate , Vijay Rao Aniket , Eltaher Basant , Sharif Muhammad Hammad 
Published: December 2024

Background: Studies have shown that when adjusted for other comorbidities, allogeneic hematopoietic stem cell transplantation (HSCT) outcomes in patients with Myelodysplastic Syndrome (MDS) are similar in patients aged &gt;65 years and patients aged between 55-64 years. This study aims to determine whether age and insurance are barriers to allogeneic HSCT in patients with MDS bearing in mind that the median age of diagnosis of MDS is 70 years. We also seek to describe the characteristics of patients with MDS undergoing allogeneic HSCT.

Methods: Retrospective analysis of the National Inpatient Database from 2016 to 2020 was performed using ICD 10 codes to code for allogeneic HSCT, MDS and comorbidities. The Institutional review board (IRB) approval was not mandatory since the NIS contains deidentified data. We applied the discharge weight (DISCWT) provided in the database to generate the national estimates. Pearson Chi-square test for categorical variables and Student's t-tests/one-way ANOVA for continuous variables were applied to compare the baseline demographics and hospital characteristics between the groups. Subgroup analysis with multivariate logistic regression analysis after adjusting for comorbidities was carried out to determine the impact of age, race and insurance status on hospitalization outcomes.

Results: A total of 30,460 patients underwent allogeneic HSCT in the US from 2016 to 2020. Among these, 4980 (16.16%) had a diagnosis of MDS. MDS patients undergoing allogeneic HSCT were more likely to be older, with a median age of 62 (IQR 56-68, p&lt;0.001), in comparison to a median age of 49 years (IQR 25-62, p&lt;0.001). Among these patients with MDS, 3900 (80.66%) patients were white, 210 (4.34%) were black, 340 (7.03%) were Hispanic, and 385 (7.96%) belonged to other races. Patients with MDS who underwent allogeneic HSCT were significantly more likely (p&lt;0.001) to have comorbidities such as chronic lung disease (11.35% vs 8.55%), Diabetes Mellitus (15.66% vs 10.06%), Hypothyroidism (13.45% vs 8.09%), Hypertension (52.61% vs 45.28%) and Obesity (11.65% vs 9.89%). A larger percentage of patients with MDS undergoing allogeneic HSCT were likely to be covered by Medicare when compared to non-MDS patients (38.73% vs 17.10%, p&lt;0.001), while they were less likely to be covered by Medicaid (6.64% vs 18.22%) and private insurance 50.80% vs 56.96%). On subgroup analysis, we found that age did not affect in-hospital mortality (aOR - 0.99, 95% CI 0.98-1.009, p=0.6614) or risk of AKI (aOR - 1.00, 95% CI 0.004-1.006, p=0.9954). While in-hospital mortality was higher in patients with the primary payer as Medicaid (aOR 2.94, 95% CI 1.65-5.22 p=0.0084), the risk of AKI and Mechanical ventilation were significantly lower in patients in whom the primary payer was Medicaid or Private insurance. With regards race, in-hospital mortality for African Americans in comparison to white population revealed an aOR 1.60 (95% CI 0.88-2.90, p=0.1190) and for Hispanics aOR of 0.45 (95% CI 0.22-0.94, p=0.0336).

Conclusion: While the median age of diagnosis of MDS is around 70 years, the median age of patients with MDS undergoing allogeneic HSCT was 62 years. Despite studies showing similar outcomes in older patients with MDS undergoing allogeneic HSCT, it appears that age might still be a barrier to receiving allogeneic HSCT. Based on our study results, it appears that age does not affect outcomes in terms of in-hospital mortality. In addition, Hispanics had lesser odds of in-hospital mortality compared to whites. MDS patients were less likely to have private insurance as their primary payer for their allogeneic HSCT. Further studies are needed to determine the implications of this with regards to undergoing an allogeneic HSCT