The Cost-effectiveness of Interventions to Promote Medication Adherence in Type 2 Diabetes

The goal of this project is to develop and validate a simulation model of diabetes prevention, care and treatment to evaluate clinical outcomes, costs, and cost-effectiveness of strategies for diabetes prevention and care. We propose an innovative approach to project the influence of long-term adherence with treatment and retention in care. Diabetes and its complications are amongst the leading causes of death in the U.S. and the growing economic burden, estimated to be $322 billion in 2012, is a major public health concern. The "cascade of diabetes care" reflects the continuum from diabetes diagnosis to linkage to care to medication adherence and retention; this cascade is a powerful illustration of the fact that of the estimated 28.4 million people living with diabetes only 20% receive treatment and achieve their targets, defined in terms of glucose, blood pressure, and lipid levels and smoking status (Figure, Ali et al., Ann Intern Med 2014). Poor adherence is the principal cause of development of complications of diabetes and their associated individual, societal and economic costs. This challenge highlights the critical impact of adherence toward achieving long-term glucose, lipid, and blood pressure control. Engagement in care is associated with better control of risk factors, which slows progression to clinical events. This emphasizes the need for economic evaluation of interventions and treatment strategies that consider important investments in mechanisms to promote engagement in care and adherence and their underlying behavioral mechanisms. Mathematical simulation models provide the necessary evidence to inform economic evaluation in comparative effectiveness research. They serve as a framework to synthesize the evidence from different sources for evidence-based medicine and allow considering all alternatives to make an informed decision. Especially important for diabetes as a chronic disease with long-term complications, simulation models enable adopting a sufficiently long time horizon to see the difference in cost and effectiveness between alternative treatments. Simulation models have long been used to inform guidelines and national policy in HIV disease, cardiovascular disease, and cancer, among others. The particular focus and novelty of the proposed research is the consideration of adherence, loss to follow up, and retention in the model formulation to project and compare the long-term cost-effectiveness of diabetes prevention and intervention programs. The main objective of the proposed research is to address the gaps in the continuum of care. Cohort data to populate the model will be based on published sources and will use health services data from the CDTR core for sensitivity analyses where published data is not available.