Travel burden associated with granulocyte colony-stimulating factor administration in a Medicare aged population: a geospatial analysis

Abstract

Objective: Prophylaxis with granulocyte colony-stimulating factors (G-CSFs) is recommended for patients receiving myelosuppressive chemotherapy regimens with a high risk of febrile neutropenia (FN). G-CSFs should be administered starting the day after chemotherapy, necessitating return trips to the oncology clinic at the end of each cycle. We examined the travel burden related to prophylactic G-CSF injections after chemotherapy in the US.

Methods: We used 2012–2014 Medicare claims data to identify a national cohort of beneficiaries age 65+ with non-myeloid cancers who received both chemotherapy and prophylactic G-CSFs. Patient travel origin was based on residence ZIP code. Oncologist practice locations and hospital addresses were obtained from the Medicare Physician Compare and Hospital Compare websites and geocoded using the Google Maps Application Programming Interface (API). Driving distance and time to the care site from each patient ZIP code tabulation area (ZCTA) were calculated using Open Street Maps road networks. Geographic and socio-economic characteristics of each ZCTA from the US Census Bureau’s American Community Survey were used to stratify and analyze travel estimates.

Results: The mean one-way driving distance to the G-CSF provider was 23.8 (SD 30.1) miles and the mean one-way driving time was 33.3 (SD 37.8) minutes. When stratified by population density, the mean one-way travel time varied from 12.1 (SD 10.1) minutes in Very Dense Urban areas to 76.7 (SD 72.1) minutes in Super Rural areas. About 48% of patients had one-way travel times of <20 minutes, but 19% of patients traveled ≥50 minutes one way for G-CSF prophylaxis. Patients in areas with above average concentrations of aged, poor or disabled residents were more likely to experience longer travel.

Conclusions: Administration of G-CSF therapy after chemotherapy can present a significant travel burden for cancer patients. Technological improvements in the form and methods of drug delivery for G-CSFs might significantly reduce this travel burden.

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

J.M.S. has disclosed that he received consulting fees from Amgen Inc. related to this study. C.S.H. has disclosed that he received a grant to his institution from Prima Health Analytics for this study; he has also received grants from the National Institutes of Health and Bristol-Myers Squibb and provided consulting services to Evogen Inc. and Catheter Connections. M.B. and C.B. have disclosed that they are employees of Amgen Inc. and own stock and/or stock options in Amgen Inc.

CMRO peer reviewers on this manuscript have received an honorarium from CMRO for their review work, but have no relevant financial or other relationships to disclose.

Acknowledgements

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