Work performed and main achievements
The project achieved significant progress across several work packages:
• Mapping the Data Landscape: Researchers conducted a systematic review identifying 573 diabetes databases across 58 countries, primarily in Europe, North America, and Asia. An online dashboard was launched to make these resources discoverable to the global research community.
• Fit-for-Purpose Assessment: The team developed a structured three-stage tool (defining the research question, data extraction, and assessment) to evaluate whether a database contains the necessary variables and follow-up time to answer specific clinical questions.
• Regulatory and HTA Standards: REDDIE reviewed 14 existing guidance frameworks and identified the Akehurst et al. framework as a foundation for developing diabetes-specific standards. Stakeholder workshops were held to refine these into normative statements for future regulatory use.
• Trial Emulation: The project emulated landmark trials (such as LEADER, EMPA-REG, and DEVOTE) using routine clinical data from registries in Denmark, Sweden, the UK, and Germany. These emulations used longitudinal targeted maximum likelihood estimation (TMLE) to ensure robust causal inference.
Specifically, we have already published analysis plans and are presently working on an analysis of the following models in RWD:
1. GLP-1 vs. DPP-4 (LEADER inspired population; carried out in DK, UK, SE)
2. SGLT-2 vs. DPP-4 (EMPA-REG inspired population; carried out in DK, UK, SE)
3. Insulin degludec vs. glargine (DEVOTE inspired population; carried out in DK)
4. DPP-4 vs. SU (TECOS inspired population; carried out in DK)
5. GLP-1 vs. DPP-4 as second-line therapy (LEAD2 inspired population; carried out in DK, GE)
6. GLP-1 receptor agonists vs. metformin as first-line therapy (LEAD1 inspired population, carried out in DK, GE, SE)
Advanced Analytics: WP5 compared various confounding-adjustment strategies and developed an augmented Propensity Score Matching (PSM) approach that automates parameter tuning to improve scalability and reproducibility. Additionally, an R library was developed to build Dynamic Bayesian Network (DBN) models for simulating complex longitudinal dependencies.