Russian registry of Surgical OutcomeS — RuSOS: study protocol

INTRODUCTION: Identification of risk factors that cause a high probability of an unfavorable outcome in the postoperative period is an urgent problem. The creation of national databases (registries) makes it possible to cover a certain patient population by identifying its risk predictors. Existing registries differ in the criteria for inclusion in the study, in the characteristics of the populations studied, and there is often no common view on the classification of postoperative outcomes. OBJECTIVE: Creation of a Russian national calculator for the risk of postoperative complications and mortality. MATERIALS AND METHODS: Two-level observational retrospective-prospective study. Setting: National multicenter study of surgical inpatients. Patients: Adult patients undergoing elective and emergency surgery. Types of interventions: obstetrics, gynecology, mammary gland, urology, endocrine surgery, maxillofacial surgery, orthopedics, traumatology, abdominal surgery, liver and biliary tract, thoracic surgery, vascular surgery, neurosurgery, cardiac surgery, other areas. RESULTS: The design was registered in the ClinicalTrials.gov database, the study was organized by the Federation of Anesthesiologists and Reanimatologists of Russia. Primary (30-day mortality, 30-day complications) and secondary (hospital mortality, hospital complications, length of stay in ICU, length of hospital stay, multiple organ failure (2 or more points on the SOFA scale), 90-day mortality, 90-day complications, post intensive care syndrome, readmission, 1-year mortality) outcomes; six primary and twelve secondary target points; criteria for inclusion, non-inclusion, exclusion. The required sample size and statistical analysis are described. The planned sample size to ensure the required power of the study is determined to be 60,800 observations for elective surgery and 20,000 observations for emergency surgery. The planned duration of the study is 2024–2028. CONCLUSIONS: The study has important scientific and medical-social significance; a Russian national calculator for the risk of postoperative complications and mortality will be developed. In the future, the developed calculator can become the basis for making medical decisions.