4 neutropenia related hospitalizations occurred per cycle, with mean despite length of stay of 12. 6 days. In the subset of pegfilgras tim cycles in which neutropenia related hospitalization occurred, an average of 1. 0 neutropenia related hospitalization occurred per cycle, lasting a mean of 7. 0 days each. Among all filgrastim cycles, 39. 7% were associated with at least one neutropenia related ambu latory visit. the corresponding percentage among all pegfilgrastim cycles was 28. 0%. During the subset of cycles in which these neutropenia related ambulatory visits occurred, the mean number of neutropenia related visits was 5. 3 for filgrastim cycles and 1. 3 for pegfilgras tim cycles. All cause resource utilization showed similar trends as that indicated for neutropenia related results, and specific all cause healthcare utilization results can Inhibitors,Modulators,Libraries be seen in Table 4.

Per cycle costs were also examined by setting of care ambulatory care, ER, and inpatient hospitalizations. Mean neutropenia related per cycle costs for all cycles were greater for filgrastim than for pegfilgrastim, with the difference being driven by the greater costs of ambula tory care. The mean neutropenia related Inhibitors,Modulators,Libraries hospitalization cost per cycle was also numerically greater Inhibitors,Modulators,Libraries for filgrastim than for pegfilgrastim. For the subset of cycles in which neutropenia related hospitalizations oc curred, the mean neutropenia related hospitalization cost of 13,457 per filgrastim cycle appeared to be statistically insignificant from the 15,069 cost per pegfilgrastim cycle.

In the subset of cycles in which neutropenia related ambulatory visits oc curred, mean neutropenia related ambulatory care costs per cycle with filgrastim were also similar to those for peg filgrastim. The combined mean costs per cycle due to all cause for all Inhibitors,Modulators,Libraries cycles were fairly similar for the two G CSF mole cules, with 9,575 for filgrastim and 9,786 for pegfilgrastim. Compared to pegfilgrastim, there were lower ambulatory care costs for filgrastim and greater hospitalization costs for filgrastim. Discussion In this retrospective United States claims analysis, use of prophylactic pegfilgrastim was associated with a decreased risk of neutropenia related hospitalization and all cause hospitalization when compared to that seen with the Inhibitors,Modulators,Libraries use of prophylactic fil grastim. Patients who received filgrastim prophylaxis in this study had a mean 4.

8 days of prophylaxis, which is much shorter than the duration which has been demon strated to be non inferior to pegfilgrastim prophylaxis in clinical trials. These results are consistent with previous findings that hospitalization risk was more sig nificantly reduced by pegfilgrastim things prophylaxis than by filgrastim prophylaxis in clinical practice. Key findings regarding utilization included an increase in neutropenia related ambulatory visits and hospitalizations with filgrastim prophylaxis compared to pegfilgrastim prophylaxis.