Diagnostic accuracy of the rapid arterial occlusion evaluation and the Cincinnati prehospital stroke scale for the prediction of large vessel occlusion stroke: a systematic review

Introduction: Stroke, particularly due to large vessel occlusion (LVO), is a significant cause of disability and mortality worldwide. Early identification in prehospital settings is crucial for implementing interventions such as mechanical thrombectomy. In this context, the Cincinnati Prehospital Stroke Scale (CPSS) and the Rapid Arterial oCclusion Evaluation (RACE) are useful as clinical tools to enhance the detection stroke. Evaluating their diagnostic accuracy may optimize their application in emergency services. Materials and Methods: A systematic review was conducted following PRISMA 2020 guidelines with the aim of evaluating the diagnostic accuracy of the RACE and CPSS scales in identifying ischemic stroke in prehospital and hospital settings. Systematic searches were conducted in PubMed, Scopus, and Web of Science, covering the period from January 1, 2020, to April 30, 2025. The search was supplemented by a manual review of the reference lists of included articles to identify potentially relevant additional studies. A total of 17 studies were included, for the evaluation of sensitivity, specificity, likelihood ratios (LR+ and LR–), methodological quality (assessed using QUADAS-2), and applicability of the CPSS, RACE, and their variants (CPSS-2, d-CPSS, and RACE-4). Results: The CPSS scale was evaluated in 13 studies, with sensitivity ranging between 57-95% and specificity between 54.3-94%. Its LR+ ranged from 1.96 to 9.83, being higher in hospital settings or in patients with high clinical suspicion. The RACE scale was evaluated in 9 studies, with sensitivity between 56-100% and specificity between 60-91%, with LR+ values up to 8.33. Scales like RACE and CPSS showed good LR– values (some close to 0.1), making them useful for ruling out stroke in emergency settings. However, CPSS-2 showed an LR– of 0.63, which reduces its utility as an exclusion test. Conclusion: Both CPSS and RACE are useful tools for early detection of LVO-related stroke, especially in prehospital environments. RACE tends to offer greater diagnostic accuracy due to its more detailed assessment of neurological deficits, while CPSS stands out for its simplicity and rapid applicability. An implementation tailored to the local healthcare system is recommended, along with more prospective studies with external validation to strengthen the available evidence.