OBJECTIVES: Evidence related to healthcare resource utilization (HCRU) for cytopenic adverse events among the multiple myeloma (MM) population is limited. This study calculated prevalence and length of stay (LOS) estimates for cytopenia-related hospitalizations among United States (US) patients with MM to better understand resource burden.

METHODS: The 2019 Healthcare Cost and Utilization Project Nationwide Inpatient Sample was analyzed to assess hospitalizations and LOS based on International Classification of Diseases 10^th version-clinical modification diagnostic codes. Adult hospitalizations were included if they had an active MM code (any diagnosis code position) and a cytopenia code for anemia, thrombocytopenia, and/or neutropenia (in a primary or secondary diagnosis code position). Results were weighted to obtain national estimates and reported overall and by cytopenia type.

RESULTS: Out of approximately 35 million inpatient admissions in 2019, 103,675 (0.29%) had an MM diagnostic code and 13,240 (13%) of those had a cytopenia code. Patients hospitalized for MM and a cytopenia were predominately White (63.6%) and male (56.2%) and had a mean age of 66.9 years. Most (10,620 [80%]) cytopenia-related MM hospitalizations had a neutropenia code recorded, followed by anemia (2265 [17.1%]), and thrombocytopenia (355 [2.7%]). Approximately 48% of neutropenia-related hospitalizations also listed a fever or infection code, suggesting febrile neutropenia; other frequent coinciding codes were for kidney-related diseases and protein/nutrient deficiencies. Mean hospitalization LOS varied by cytopenia type ranging from an anemia-related hospitalization of 4.7 days to 10.0 days for a hospitalization with a neutropenia plus fever or infection code.

CONCLUSIONS: Results suggest that a meaningful number of hospitalizations were related to the experience of cytopenias, especially neutropenia, among US adults with active MM. Management of neutropenia/febrile neutropenia may be key to reducing hospitalizations and LOS in MM patients. Further exploration into potential drivers of HCRU, such as MM treatment type, in this population are warranted.