Clinical Research Details Clinical Research A Validation Study for the AAST Grading for Acute Cholecystitis and Comparison with Other Systems Study Description The purpose of this multi-institutional study is to assess predictive power of available grading scales for acute cholecystitis with respect to patient outcomes when measured across multiple institutions. Performance of the American Association for the Surgery of Trauma (AAST) grading system will be compared to the performance of other grading systems. Inter-rater reliability will be assessed in an attempt to optimize the scoring system. Optimization of the operative component of the score will be done by assessing performance of a recently validated operative score and considering it for inclusion in the AAST system. In addition, researchers plan to develop an improved grading scale for acute cholecystitis that will predict outcomes across the range of disease severity and will be applicable regardless of the treatment strategy chosen. Yale University will be the coordinating center for this multi-institutional trial, with 30 participating centers nationwide. Retrospective review of medical records will be performed to obtain study data while maintaining patient confidentiality. Adult patients, greater than 18 years of age, presenting to UF Health Jacksonville with a primary diagnosis of acute cholecystitis will be included. Data collection will be extensive for clinical and imaging findings so correlation of clinical and imaging findings with operative findings and patient outcomes may be performed. Investigators Marie L. Crandall, M.D., M.P.H., FACS Surgery Ruchir Puri, M.B.B.S. (M.D.), M.S., FACS Surgery