Ibrutinib has proven to be very effective in newly diagnosed and relapsed chronic lymphocytic leukemia (CLL) patients. However, it can cause certain side effects that can lead to early discontinuation of treatment and worse outcomes for patients. The goal of this study is to determine the frequency of side effects in the “real-world” associated with ibrutinib compared to standard therapy using provincial administrative data. We further aim to assess the impact of ibrutinib dose interruptions and reductions on survival outcomes, as well as the impact and cost of the side effects of therapy on the public health care system. As a subproject, we aim to determine survival outcomes of patients based on predictive markers analyzed at diagnosis and at time of treatment. Results from our study will provide information to health care organizations regarding “real-world” risks of ibrutinib and the value of predictive markers to the health of CLL patients.