CONCEPT is a coordinated research initiative made up of five projects within the framework of RICAPPS – Research Network on Chronicity, Primary Care and Health Promotion. The general objective of CONCEPT is the study of the effectiveness and efficiency of chronic care in the Spanish National Health System: a multi-cohort study with real-world data. Specifically, how care is provided for patients with diabetes CONCEPT-DIABETES, for long-term survivors of breast cancer CONCEPT-SURBCAN, for patients with heart failure CONCEPT-Heart Failure, and for those with acute ischemic stroke CONCEPT- STROKE. CONCEPT projects will address research questions related to the effectiveness and efficiency (ie adequacy, quality or health outcomes and costs) with which chronic care is provided in the context of the Spanish healthcare system. CONCEPT comprises five sub-projects, four of which will analyze the care provided to four high-prevalence chronic diseases and a fifth CONCEPT-COST, focused on the economic analyzes of all other projects. CONCEPT projects are based on the actual exposure of patients when they come into contact with different healthcare providers and the consequences of that exposure, using Real World Data (RWD) as a research substrate.