Despite the widespread success of chemotherapy in treating various forms of cancer, its use is limited by certain toxicities like neutropenia. Colony stimulating factors (CSF), when used prophylactically, are useful in preventing febrile neutropenia (FN), as well as reducing its duration and severity. The American Society of Clinical Oncology (ASCO) guidelines recommend CSF for prophylaxis in cancer patients, but also recommend chemotherapy dose reduction as a viable alternative. The goal of this research was to assess and compare the use of CSF and dose reduction among metastatic colorectal cancer patients and factors that influence their use. The study also tested the impact of a program initiative on CSF prescription patterns. For this retrospective observational study, data were obtained from the electronic health records of metastatic colorectal cancer patients who received care at a multi-center oncology practice network in two time periods. The outcomes of interest were CSF use, chemotherapy dose reduction and all-cause mortality. Logistic regression techniques were utilized in exploring the relationships between these outcomes and some variables namely age, gender, FN risk, line of therapy, duration of treatment, year of diagnosis and disease . In 2016, a site-wide program initiative was introduced in the oncology practice network, with an aim of improving appropriate use of CSFs and compliance to guidelines on CSF use. The study had a total of 3426 regimens, corresponding to 2968 unique patients. A total of 11% of the patients used CSF (N=387). CSF use was significantly lower in the postperiod, compared to the pre-period (p<0.0001). Compliance to guidelines was significantly higher in the post-period, compared to the pre-period (p<0.0001). Among subjects who had data on dose reduction (N=508), 58.7% received dose reduction distinctively. Factors that were significantly associated with CSF include age, FN risk, gender, line of therapy and duration of treatment. Factors associated with dose reduction include FN risk and duration of treatment, while factors associated with mortality include age, line of therapy, duration of treatment and gender. The study found no difference in mortality between CSF users and patients who received dose reduction (p=0.2030). Program initiatives have the potential to positively impact prescription patterns. Also, there was no benefit of CSF use over dose reduction in terms of mortality. These conclusions could help decrease CSF overutilization and result in enhanced clinical practice and cost savings, without compromising health outcomes