Purpose: Growth factors and antimicrobials can reduce complications of chemotherapy-induced myelosuppression. Their prophylactic use in elderly patients is important given the associated comorbidity in this age group. There is a developing trend by payers to include supportive care agents in chemotherapy care bundles, which could affect clinical practice. We examined whether the febrile neutropenia (FN) risk categories can be used to describe utilization in the Centers for Medicare & Medicaid fee-for-service system in older adults.
Methods: We conducted a retrospective cohort study using the Medicare 20% sample data to describe growth factor and antimicrobial use patterns in patients receiving chemotherapy for breast cancer, lung cancer, and non-Hodgkin lymphoma (NHL).
Results: The highest percentage of patients receiving granulocyte colony-stimulating factor (GCSF) within the first 5 days of a chemotherapy cycle were on high-FN-risk regimens, particularly for cycle 1 (73.7%, breast cancer; 61.5%, NHL) and cycle 2 (75.9%, breast cancer; 77.5%, NHL). Chemotherapy regimens for lung cancer are less myelotoxic, and growth factor use was more likely with latter cycles. Antibiotic use was lower at 15% within a cycle and appeared to be in response to complications.
Conclusion: Practitioners use GCSF and antibiotics for elderly patients treated with potentially toxic chemotherapy, while comorbidity burden plays a role for patients treated with less myelotoxic regimens. The complexity of these choices in clinical practice should be considered in the proposed reimbursement changes being piloted by Medicare and private insurance companies seeking treatment cost reductions, as altered use could affect safety and efficacy.
Keywords: Antimicrobials; Chemotherapy; Febrile neutropenia; Granulocyte colony-stimulating factor.