RESUMO
BACKGROUND: Clinical scoring systems have been used to reduce negative appendectomy rate for several decades. However, the use of these systems has been questioned due to differences in their diagnostic accuracies. The aim of this prospective study was to develop a new clinical scoring system using a combination of all previously described variables for the diagnosis of acute appendicitis (AA). METHODS: Consecutive patients who underwent emergency appendectomy for AA between December 2016 and April 2017 were prospectively included in the study. During admission, a prepared questionnaire including variables obtained from the previously used clinical scoring systems was administered. Histopathological analysis was regarded as the main outcome. Patients with no histopathological evidence of AA were defined as negative appendectomy. All variables were analyzed separately to assess their association with AA. A receiver operating characteristic curve with area under curve analysis was performed to obtain the cut-off values for numerical variables. RESULTS: There were 200 patients with a mean age of 30.8±12.8 years with a negative appendectomy rate of 5.5%. There was no significant association between the variables and the detection of histologically proven AA except increased white blood cell count >11.05/mm3 and proportion of the polymorphonuclear leukocytes >71.2% (p=0.003 and p=0.015, respectively). CONCLUSION: The present study shows that the development and/or use of scoring systems does not significantly improve the diagnostic accuracy of AA.