National and interprovincial prescribing patterns of JAK-inhibitors in Canada: a repeated cross-sectional analysis

Janus Kinase (JAK) inhibitors have emerged as a novel category of medications to treat a variety of immune-mediated conditions. However, limited insight exists regarding the impact of safety concerns on their usage and prescribing practices. Therefore, the objective of this study was to describe the utilization of JAK-inhibitors in Canada, both nationally and within individual provinces. We used data from IQVIA's Compuscript database. We conducted a repeated cross-sectional study of all JAK-inhibitor units dispensed in retail pharmacies (tofacitinib, ruxolitinib, baricitinib, and upadacitinib) within the ten Canadian provinces from July 1, 2016, to June 30, 2022. Throughout Canada, outpatient pharmacies dispensed an estimated total of 26,126,409 JAK-inhibitor units between 2016 and 2022, averaging 9,431 units dispensed per 100,000 population. All provinces had increasing rates of JAK-inhibitor units dispensed over time, whereby between July 2021 to June 2022, New Brunswick exhibited the highest rates (27,696 units per 100,000), and Prince Edward Island demonstrated the lowest rates (10,065 units per 100,000). In this study, utilization of JAK-inhibitors increased in Canada over the study period, evident at both provincial and national levels. Variability in JAK-inhibitor utilization between provinces underscores the necessity for further investigations to ascertain appropriate usage practices. Key Points • From 2016 to 2022, an estimated total of 26,126,409 JAK-inhibitor units were dispensed in retail pharmacies across Canada, with an average rate of 9,431 units dispensed for every 100,000 people in the population. • Tofacitinib was the most dispensed JAK-inhibitor during the entire study period, making up 76% of all units dispensed. Ruxolitinib, upadacitinib, and baricitinib made up 16%, 7.9%, and 1.1% of the JAK-inhibitor units dispensed, respectively. • The variance in provincial adoption of JAK-inhibitors across Canada might be influenced by several factors, including drug coverage availability, disease prevalence, and physician prescribing patterns.