Factors Associated with Receipt of Allogeneic Hematopoietic Cell Transplant and NMDP Donor Search in Older Adults with Acute Myeloid Leukemia.

BACKGROUND

Treatments for older adults with acute myeloid leukemia (AML) are often underutilized, with older adults often receiving no active treatment. Little is also currently known about patient, physician, and hospital factors that may play a role in the treatment older adults receive. The objective of this study was to identify the association of patient, hospital, and physician factors with treatment pathways among adults age 65 to 75 years diagnosed with AML. Treatment pathways included (1) chemotherapy with allogeneic hematopoietic cell transplantation (alloHCT); (2) chemotherapy with an NMDP search (chemo with search); (3) chemotherapy without an NMDP search (chemo without search); and (4) no chemotherapy or alloHCT (no therapy).

METHODS

This retrospective cohort study linked Centers for Medicare and Medicaid (CMS) Medicare claims, NMDP donor search, and publicly available CMS and National Provider Identifier (NPI) physician and hospital datasets. Patients age 65 to 75 years diagnosed with AML between 2010 and 2017 who were enrolled in fee-for-service (Parts A and B) Medicare for at least 1 year after diagnosis or until death were included. AlloHCT and chemotherapy were identified using diagnosis and procedure codes; no therapy was identified if there were no alloHCT or chemotherapy codes. Multivariable hierarchical logistic regression was used to identify patient, hospital, and physician factors associated with treatment receipt, with hospital as a random effect.

RESULTS

A total of 4394 patients met eligibility criteria: 599 (13.6%) received alloHCT, 655 (14.9%) received chemo with search, 2762 (62.9%) received chemo without search, and 378 (8.6%) received no therapy. Receipt of alloHCT was associated with year of diagnosis, sex, race, education, and age when compared with chemo with search. Compared with those who received chemo without search, receipt of alloHCT was associated with year of diagnosis, race, education, region, Elixhauser comorbidity index (ECI), and age. Receipt of alloHCT when compared with receipt of no therapy was associated with year of diagnosis, education, ECI, age, medical school affiliation, years since medical school graduation, and specialty. Among those receiving chemotherapy alone, factors associated with search included year of diagnosis, sex, education, ECI, and age.

CONCLUSION

This population-based analysis assessed the association of patient, hospital, and physician characteristics at the time of AML diagnosis with receipt of alloHCT and donor search in the first year after diagnosis for adults aged 65 to 75 with Medicare coverage. Results highlight that older age, higher comorbidities, and lower education are key barriers to receiving alloHCT and donor search. Physician- and hospital-level factors, such as lack of medical school affiliation and non-hematologist specialty, can further limit access, as seen by the association with receipt of alloHCT when compared with those who received no therapy but not chemotherapy with or without a donor search. Additional research and interventions are needed to improve access to treatment, focusing on age-related, geographic, and referral barriers. They could include educational outreach for older adults and standardized referral guidelines to support timely transplant evaluation.