External Validation Study of San Francisco Syncope Rule Based on Standardized Reporting Guidelines for Emergency Department Syncope Risk Stratification Research

ABSTRACT

PURPOSE: We validated the performance of the San Francisco Syncope Rule (SFSR) for accurate identification of Korean emergency department (ED) syncope patients who will experience a short term serious outcome. METHODS: This retrospective study included patients over 16 years old who fulfilled the inclusion criteria according to the definition of syncope and visited the ED from January 2010 to June 2013. The authors excluded patients with alcohol or illicit drugs use seizure, stroke or transient ischemic attack, head trauma followed by loss of consciousness, or hypoglycemia. The patients were divided into two groups according to the SFSR for the purpose of performing a comparative analysis. The authors calculated sensitivity, specificity, positive predictive value, and negative predictive value of SFSR and analyzed other variables, except five predictor variables of SFSR. RESULTS: Of 1,235 visits screened, 409 were included. The average age of enrolled patients was 55.2+/-20.1 and male population accounted for 45.0%(n=184). A total of 93(27.7%) patients experienced serious outcomes; 41 of 287(14.3%) patients with a serious outcome were not identified as high risk according to the rule. The rule performed with a sensitivity of 55.9%, specificity of 77.8%, positive predictive value of 42.6%, and negative predictive value of 85.7%. CONCLUSION: In this retrospective validation study based on the standardized reporting guidelines for ED syncope risk stratification research, the SFSR performed with significantly lower sensitivity than previously reported. The results suggest that application of the original rule has limited generalizability and conduct of future studies will be needed in order to refine the SFSR.