RADAR-Septic Shock is a population-based observational study in Catalonia (Spain) that will identify all hospital discharges with septic shock between 2018 and 2023 using an audited population-based registry. The project will quantify incidence, describe patient characteristics and resource use, and compare risk-adjusted in-hospital mortality across hospitals to support quality improvement. Cases are defined by ICD-10 codes for septic shock (R65.21) and post-procedural septic shock (T81.12XA). In preliminary cohort counts, \>31,000 episodes were identified across 2018-2023; in 2023 the incidence was \~78 per 100,000 inhabitants with an overall in-hospital mortality of \~33%, higher in hospital-acquired than community-acquired episodes