Introduction: Acute appendicitis is the more frequent surgical emergency in the world. Its diagnosis has been mostly clinical with some laboratory tests, however in the last 20 years have been introduced aids like the computed tomography (CT) with evidence in favour and against its routine use. Objectives: Estimate the incidence of negative appendectomy and perforated appendicitis, using the Computed Tomography vs clinical assessment, in the Hospital Universitario Mayor-Méderi, in the period of time between 2015 - 2016. Methods: Retrospective cohort study with revision of medical records of patients with appendectomy, the results were compared between those with CT and those with clinical assessment alone. The outcomes were the incidence of negative appendectomies and perforated appendicitis in the two cohorts. Results: The incidence of negative appendectomy was 10, 9% and the incidence of perforated appendicitis was 31, 2%. In patients with CT, the incidence of negative appendectomy was 8. 1% vs 12, 4% in those with clinical assessment (RR 0,652, CI95% 0,374-1,137, adjusted OR 0,371, CI95% 0,187-0,736). The incidence of perforated appendicitis was 39, 8% in patients with CT vs 26, 9% in patients with clinical assessment alone (RR 1, 48 CI95% 1, 16-1, 88, adjusted OR 0,994 CI95% 0,595-1,659). Conclusion: In patients in whom CT was used, a lower incidence of negative appendectomy was found without finding an increase in the incidence of perforated appendicitis once it was adjusted for confusing variables.
