Risks and consequences of travel burden on prophylactic granulocyte colony-stimulating factor administration and incidence of febrile neutropenia in an aged Medicare population

Abstract

Objective: Granulocyte colony-stimulating factors (G-CSFs) decrease the incidence of febrile neutropenia (FN) in patients receiving myelosuppressive chemotherapy. This study examines the impact patient travel burden has on administration of prophylactic G-CSFs and the subsequent impact on FN incidence.

Methods: Medicare claims data were used to identify a cohort of beneficiaries age 65+ with non-myeloid cancers at high risk for FN between January 2012 and December 2014. Driving distance and time were calculated from patient residence ZIP code to the location of G-CSF and/or chemotherapy administration. Regression models were used to estimate the odds of G-CSF prophylaxis relative to patient driving distance and time, and odds of FN incidence relative to timing of G-CSF administration (optimal [days 2–4 after chemotherapy], sub-optimal [same day], or none).

Results: The 52,389 study patients had a mean age of 73.5 years, and were 82% female and 89% white race; 49% had female breast cancer, 12% lung cancer, 15% ovarian cancer, and 24% non-Hodgkin’s lymphoma. Of these high FN risk patients, 69% had at least one prophylactic G-CSF administration within at least one chemotherapy cycle. The percentage of patients receiving prophylactic G-CSFs in the first cycle was 56%. Median travel time was slightly longer for patients who did not receive G-CSFs and patients receiving short-acting vs long-acting G-CSFs. The odds of receiving no G-CSFs were 26–52% higher (depending on cancer type) for patients with a >80-min one-way travel time, compared to patients traveling <20-min. Concurrently, the odds of FN (using a “narrow” definition) were 18–93% higher for patients who did not receive G-CSFs in the first cycle of chemotherapy.

Conclusions: Travel burden, linked to clinic visits for G-CSF administration following myelosuppressive chemotherapy, is associated with sub-optimal use of G-CSF prophylaxis, which may result in a higher incidence of FN.

Keywords:

• Febrile neutropenia
• Granulocyte colony-stimulating factor
• Medicare
• Oncologists
• Travel
• Geographic mapping
• Vulnerable populations

Transparency

Declaration of funding

This study was sponsored by Amgen, Inc. The study sponsor played a role in study design, interpretation of data, and writing of this manuscript.

Declaration of financial/other relationships

JMS received consulting fees from Amgen, Inc. related to this study. CH received a grant to his institution from Prima Health Analytics for this study. CH has also received grants from the National Institutes of Health/National Institute of Nursing Research, Bristol-Myers Squibb, and provided consulting services to Evogen Inc. and Catheter Connections. MB and CB are employees of Amgen, Inc. MB owns stock and/or stock options in Amgen Inc. CMRO peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Acknowledgments

The authors wish to thank Eric Shaefer, The Pennsylvania State University College of Medicine, and Sam Brotherton, Cairn Labs, LLC, who provided data programming support for this study.