Evaluating the real-world impact of Internet-delivered Cognitive Behavioural Therapy (iCBT) through the lens of the RE-AIM framework: a retrospective cohort study in Ontario

Mental health (MH) disorders are common, affecting up to one in five Canadians each year, and causing substantial disability and economic burden. Yet many do not receive sufficient MH services to meet their needs. Given these growing demands, in 2020, Ontario launched Internet-delivered Cognitive Behavioural Therapy (iCBT), a short series of online modules that were shown to be effective tor treating anxiety and depression when investigated in randomized controlled trials. However, the real-world impact of iCBT when implemented in routine care is unknown. To address this gap, in my dissertation, I will: (1) describe the characteristics of individuals receiving iCBT in routine care; (2) examine patient outcomes, including depression and anxiety symptom reductions and health service use (e.g., visits to doctors, emergency departments, and hospitalizations) before and after the intervention; and (3) quantify health-system costs. In doing so, my study will assess whether iCBT reaches those in need of MH services and how it impacts both patient- and health-system outcomes. With the COVID-19 pandemic reinforcing the urgency for developing virtual MH supports, this research will inform the wide-scale implementation of iCBT to ensure that this promising intervention improves the delivery of MH services in the province and beyond.