Validation of Utstein-Based score to predict return of spontaneous circulation (UB-ROSC) in patients with out-of-hospital cardiac arrest

Background Prediction of probability of return of spontaneous circulation (ROSC) during out-of-hospital cardiac arrest (OHCA) is one of the biggest challenge in resuscitation science. The Utstein Based-ROSC (UB-ROSC) score has been developed to predict ROSC in OHCA’s victims. Aim of the study was to validate UB-ROSC score using two large Utstein-based OHCA registries: the SWiss REgistry of Cardiac Arrest (SWISSRECA) and the Lombardia Cardiac Arrest Registry (Lombardia CARe), northern Italy. Methods Consecutive OHCA of any etiology occurring between January 1st, 2019 and December 31st and registered in 2 large national registries were included in a prospectively designed validation study. For model validation, a model area under the ROC curve (AUC ROC) for discrimination, using 10-fold cross-validation was computed. The score was plotted against the survival to hospital admission. Results 14,715 patients were included in the study. A sustained ROSC was obtained in 3,151 patients (21%). Overall, UB-ROSC model showed a good discrimination (AUC 0.72, 95% CI 0.71-0.73). Shape of risk predicted by the model was almost linear and the model resulted well calibrated. In the low likelihood subgroup of UB-ROSC, only 9% of patients achieved a ROSC. This proportion raised to 35% for UB-ROSC score between −18 and 12 (OR 5.3, 95% CI 2.9-9.4, P<0.001). Finally, in 85% of patients with UB-ROSC values of more than or equal to 13 a ROSC was obtained (OR 52.1, 95%CI 15.6-173.0, P <0.001). Conclusions UB-ROSC score may represent a reliable tool to predict ROSC probability. Its application may help the decision-making process providing a realistic stratification of probability of ROSC achievement. Clinical perspectives What is new? What are the clinical implications? ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement The Lombardia CARe is a research project of the Fondazione IRCCS Policlinico San Matteo and partially supported by Fondazione Banca del Monte di Lombardia. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The Lombardia CARe registry was approved by the Ethical Committee of the Fondazione IRCSS Policlinico San Matteo (proc. 111 20140028219) and by all others who were territorially involved. SWISSRECA is approved by the national Ethical committee (Swissethics-ID-2016-01844) and IVR-IAS is responsible for its maintenance. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes The dataset is available on request.