Rationale and Design for the J-DISCOVER Study: DISCOVERing the Treatment Reality of Type 2 Diabetes in a Real-World Setting in Japan-A Protocol

Introduction: It is estimated that 642 million adults worldwide will have diabetes by 2040, with 80-90% of these having type 2 diabetes mellitus (T2DM). While many new antidiabetic agents have been introduced in recent years, approximately 40% of T2DM patients still fail to achieve the recommended target HbA1c of < 7.0%. Furthermore, many patients with T2DM in Japan are treated by practitioners other than diabetes specialists; therefore, the exact treatment patterns of T2DM in Japan are difficult to quantify. Aims: J-DISCOVER aims to address the lack of data on the management of T2DM by providing real-world data on disease management patterns and associated outcomes in a large number of Japanese T2DM patients who are initiating second-line therapy. Design and Setting: Part of the global DISCOVER study program, J-DISCOVER will follow 2000 T2DM patients recruited from 141 sites across Japan who are aged >= 20 years. Recruitment began in September 2014 and follow-up will end in December 2018. The primary objective is to describe the long-term disease management patterns and clinical evolution of patients with T2DM inadequately controlled with a first-line antidiabetic therapy who initiate a second-line antidiabetic treatment. We will assess the associations between treatment patterns, including the line of antidiabetic medication used, as well as clinical and patient-reported outcomes. The primary endpoint is the mean change in HbA1c between baseline and at 6, 12, 24, and 36 months in the overall population and for patients receiving each class of second-line antidiabetic treatment. Planned Outputs: A peer-reviewed publication reporting real-world results and implications for clinical practice. Conclusion: By enrolling and following a large number of patients with T2DM across Japan, J-DISCOVER is expected to provide important real-world clinical data for the development of future T2DM treatment guidelines.