The Use of Granulocyte Colony–Stimulating Factors in a Canadian Outpatient Setting

Background: Data on real-life utilization of granulocyte colony– stimulating factors (g-csfs) in Canada are limited. The objective of the present study was to describe the reasons for, and the patterns of, g-csf use in selected outpatient oncology clinics in Ontario and Quebec. Methods: In a retrospective longitudinal cohort study, a review of medical records from 9 Canadian oncology clinics identified patients being prescribed filgrastim (fil) and pegfilgrastim (peg). Patient characteristics, reasons for g-csf use, and treatment patterns were descriptively analyzed. Results: Medical records of 395 patients initiating g-csf therapy between January 2008 and January 2009 were included. Of this population, 80% were women, and breast cancer was the predominant diagnosis (59%). The most commonly prescribed g-csf was fil (56% in Ontario and 98% in Quebec). The most frequent reason for g-csf use was primary prophylaxis (42% for both fil and peg), followed by secondary prophylaxis (37% fil, 41% peg). Those proportions varied by tumour type and chemotherapy regimen. Delayed g-csf administration (more than 1 day after the end of chemotherapy) was frequently observed for fil, but rarely reported for peg, and that finding was consistent across tumours and concurrent chemotherapy regimens. Conclusions: The use of g-csf varies with the malignancy type and the provincial health care setting. The most commonly prescribed g-csf agent was fil, and most first g-csf prescriptions were for primary prophylaxis. Delays were frequently observed for patients receiving fil, but were rarely reported for those receiving peg.