Demographic characteristics and cost of treatment among oncology patients in a publicly funded system, the Ontario Trillium Drug Program: a retrospective cohort study

BACKGROUND: The aim of this study was to characterize the demographic characteristics and investigate the cost of a publicly funded system, the Ontario Trillium Drug Program (TDP), for an oncology patient population. METHODS: We ascertained all TDP claims between April 1997 and December 2016 from the Ontario Drug Benefit database to assess use and cost. Each drug was classified as a cancer treatment drug, cancer supportive therapy drug or noncancer drug. We also identified a cohort of patients with cancer with least 1 TDP claim, for whom we examined demographic and claims-related characteristics. RESULTS: Over the study period, 50 975 293 TDP claims totalling $4.8 billion were made. Although the proportion of cancer claims among all TDP claims remained constant between 1997 and 2016, the total annual cost of cancer treatment drugs increased nearly 40-fold. Imatinib and lenalidomide together accounted for nearly half of the cost of all cancer treatment drugs. We identified a cohort of 49 892 patients with cancer, of whom 18 631 (37.3%) were enrolled in the TDP before their cancer diagnosis and 31 261 (62.7%) were enrolled after their diagnosis. The former were more likely than the latter to be in lower income quintiles and to have more chronic conditions. Significant differences were also found in the distribution of cancer diagnoses between the 2 groups. INTERPRETATION: In the TDP, use increased over time and differed across cancer diagnoses and drugs. These results have public health and policy implications as antineoplastic drug costs continue to rise and place a burden on patients.