Background:Acute abdominal pain is a common symptom of emergency patients.The severity was always evaluated based on physicians' clinical experience.The aim of this study was to establish an early risk stratification method (ERSM) for addressing adults with acute abdominal pain,which would guide physicians to take appropriate and timely measures following the established health-care policies.Methods:In Cohort 1,the records of 490 patients with acute abdominal pain that developed within the past 72 h were enrolled in this study.Measurement data and numeration data were compared with analysis of variance and Chi-square test,respectively.Multiple regression analysis calculated odd ratio (OR) value.P and OR values showed the impacts of factors.ERSM was established by clinical experts and statistical experts according to Youden index.In Cohort 2,data from 305 patients with acute abdominal pain were enrolled to validate the accuracy of the ERSM.Then,ERSM was prospectively used in clinical practice.Results:The ERSM was established based on the scores of the patient's clinical characteristics:right lower abdominal pain + 3 × diffuse abdominal pain + 3 × cutting abdominal pain + 3 × pain frequency + 3 × pain duration + fever + 2 × vomiting + 5 × stop defecation + 3 × history of abdominal surgery + hypertension history + diabetes history + hyperlipidemia history + pulse + 2 × skin yellowing + 2 × sclera yellowing + 2 × double lung rale + 10 × unconsciousness + 2 × right lower abdominal tendemess+ 5 × diffuse abdominal tendemess+ 4 × peritoneal irritation + 4 × bowel sounds abnormal + l 0 × suspicious diagnosis + white blood cell count + hematocrit + glucose + 2 × blood urea nitrogen + 3 × creatine + 4 × serum albumin + alanine aminotransferase + total bilirubin + 3 × conjugated bilirubin + amylase.When the score was ＜18,the patient did not need hospitalization.A score of≥l 8 and ＜38 indicated that the patient should be under observation or hospitalized.A score of≥3 8 and ＜50 indicated the need for an emergent operation.A score of≥50 indicated the need for admission to the Intensive Care Unit.The area under the receiver operating characteristic curve of the ERSM in Cohorts 1 and 2 were 0.979 and 0.988,respectively.Conclusions:This ERSM was an accurate and reliable method for making an early determination of the severity of acute abdominal pain.There was the strong correlation between scores of ERSM and health-care decision-making.