Evaluation of the accuracy, safety, utility and feasibility of using an urgency self-assessment application in self-referred patients in the emergency department: study protocol for a prospective, multicenter cohort trial

评估在急诊科自行就诊患者中使用紧急程度自我评估应用程序的准确性、安全性、实用性和可行性：一项前瞻性、多中心队列试验的研究方案