title: Pegfilgrastim prophylaxis is associated with a lower risk of hospitalization of cancer patients than filgrastim prophylaxis: a retrospective United States claims analysis of granulocyte colony-stimulating factors (G-CSF).
abstract: BACKGROUND
  Myelosuppressive chemotherapy can lead to dose-limiting febrile neutropenia. Prophylactic use of recombinant human G-CSF such as daily filgrastim and once-per-cycle pegfilgrastim may reduce the incidence of febrile neutropenia. This comparative study examined the effect of pegfilgrastim versus daily filgrastim on the risk of hospitalization.
  
  
  METHODS
  This retrospective United States claims analysis utilized 2004-2009 data for filgrastim- and pegfilgrastim-treated patients receiving chemotherapy for non-Hodgkin's lymphoma (NHL) or breast, lung, ovarian, or colorectal cancers. Cycles in which pegfilgrastim or filgrastim was administered within 5 days from initiation of chemotherapy (considered to represent prophylaxis) were pooled for analysis. Neutropenia-related hospitalization and other healthcare encounters were defined with a "narrow" criterion for claims with an ICD-9 code for neutropenia and with a "broad" criterion for claims with an ICD-9 code for neutropenia, fever, or infection. Odds ratios (OR) for hospitalization and 95% confidence intervals (CI) were estimated by generalized estimating equation (GEE) models and adjusted for patient, tumor, and treatment characteristics. Per-cycle healthcare utilization and costs were examined for cycles with pegfilgrastim or filgrastim prophylaxis.
  
  
  RESULTS
  We identified 3,535 patients receiving G-CSF prophylaxis, representing 12,056 chemotherapy cycles (11,683 pegfilgrastim, 373 filgrastim). The mean duration of filgrastim prophylaxis in the sample was 4.8 days. The mean duration of pegfilgrastim prophylaxis in the sample was 1.0 day, consistent with the recommended dosage of pegfilgrastim - a single injection once per chemotherapy cycle. Cycles with prophylactic pegfilgrastim were associated with a decreased risk of neutropenia-related hospitalization (narrow definition: OR = 0.43, 95% CI: 0.16-1.13; broad definition: OR = 0.38, 95% CI: 0.24-0.59) and all-cause hospitalization (OR = 0.50, 95% CI: 0.35-0.72) versus cycles with prophylactic filgrastim. For neutropenia-related utilization by setting of care, there were more ambulatory visits and hospitalizations per cycle associated with filgrastim prophylaxis than with pegfilgrastim prophylaxis. Mean per-cycle neutropenia-related costs were also higher with prophylactic filgrastim than with prophylactic pegfilgrastim.
  
  
  CONCLUSIONS
  In this comparative effectiveness study, pegfilgrastim prophylaxis was associated with a reduced risk of neutropenia-related or all-cause hospitalization relative to filgrastim prophylaxis.
authors.affiliation: Department of Medicine, Division of Hematology-Oncology, Jonsson Comprehensive Cancer Center, University of California, Los Angeles, CA, USA. ANaeim@mednet.ucla.edu
authors.forename: Arash
authors.initials: A
authors.lastname: Naeim
authors.forename: Henry J
authors.initials: HJ
authors.lastname: Henk
authors.forename: Laura
authors.initials: L
authors.lastname: Becker
authors.forename: Victoria
authors.initials: V
authors.lastname: Chia
authors.forename: Sejal
authors.initials: S
authors.lastname: Badre
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Li
authors.forename: Robert
authors.initials: R
authors.lastname: Deeter
mesh_terms: D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000009:adverse effects*; D003362:Cost-Benefit Analysis; D004334:Drug Administration Schedule; D016527:Drug Costs; D005260:Female; D000069585:Filgrastim; D016179:Granulocyte Colony-Stimulating Factor / Q000008:administration & dosage* / Q000191:economics; D017721:Hospital Costs; D006760:Hospitalization / Q000191:economics; D006801:Humans; D007356:Insurance, Pharmaceutical Services; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000188:drug therapy* / Q000191:economics; D009503:Neutropenia / Q000139:chemically induced / Q000191:economics / Q000517:prevention & control*; D016017:Odds Ratio; D011092:Polyethylene Glycols; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000191:economics; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D014481:United States
chemical_list: D000970:Antineoplastic Agents; D011994:Recombinant Proteins; D016179:Granulocyte Colony-Stimulating Factor; C455861:pegfilgrastim; D011092:Polyethylene Glycols; D000069585:Filgrastim