Objective Tools for Assessing the Probability of Acute Appendicitis in Domestic Practice

RELEVANCE In order to objectify the diagnosis of acute appendicitis, a number of scales have been developed, the foreign practice of using which implies performing computed tomography in the case of obtaining intermediate point values corresponding to the average probability of acute appendicitis. This tactical solution, which is still difficult to implement in domestic conditions, limits the use of diagnostic scales and serves as a reason to search for other ways of using them. AIM OF THE STUDY To evaluate the external validity of the AIRS, Ripasa, AAS and Alvarado scales on the available clinical material and upon obtaining satisfactory results, to determine the applicability of these classifiers in matters of making specific tactical decisions. MATERIAL AND METHODS The work is based on the analysis of medical records of 293 patients hospitalized with suspected acute appendicitis at the St. Petersburg State Healthcare Institution “Elizavetinskaya Hospital” in the period from 2019 to 2022. Using information on postoperative diagnoses, the values of the AIRS, Ripasa, AAS and Alvarado scores were retrospectively calculated for each of the patients examined, followed by a comparison of the results obtained and the outcomes of hospitalization by conducting a regression analysis. RESULTS The AIRS, Ripasa, AAS, and Alvarado scales for assessing the probability of acute appendicitis, as applied to the analyzed group of patients, demonstrated external validity due to the preservation of referral threshold values, good description of the studied binary variance (AUC greater than 0.8), and sufficiently high adjusted correlation coefficients (from 0.57 and higher). The final diagnostic accuracy for all analyzed classifiers did not differ statistically significantly and was at acceptable levels of 78.8%, 76.7%, 76.7%, and 75.7% for the AIRS, Ripasa, AAS, and Alvarado scales, respectively (p=0.115). The hypothetical choice of the upper limit of low risk as the threshold value after which all patients are subject to diagnostic laparoscopy may lead to a statistically significant decrease in the number of inpatient observations of patients with acute appendicitis without increasing the frequency of diagnostic laparoscopies in healthy patients. CONCLUSION The use of the AIRS, Ripasa, AAS and Alvarado assessment scales is advisable both from the standpoint of diagnosing acute appendicitis and for making tactical decisions, provided that patients with intermediate scale values are shifted towards active surgical actions.