The Alvarado Score for Appendicitis – Not as Sensitive as Previously Indicated – A Retrospective Review

Isaac Payne, DO, Daniel Freno, MD, Jon Simmons, MD, Sidney B, MPH, MD. University of South Alabama Medical Center

Introduction: The current literature suggests the Alvarado score is a highly sensitive and specific clinical score for evaluation of patients suspected of acute appendicitis. We hypothesize that although an Alvarado score > 7 may positively predict appendicitis, CT scan is still a more sensitive tool for predicting the diagnosis of appendicitis.

Methods: We retrospectively evaluated all patients from 2011 to 2015 who underwent appendectomy for suspected appendicitis at our institution. A total of 107 patents were included in the study, 96(90%) had a confirmed diagnosis of appendicitis on pathology.  We then compared CT findings and Alvarado scores with the patients final pathologic diagnosis.  Sensitivities for the two groups were compared as well as predictive values.

Results: For an Alvarado score of > 7 , the sensitivity was 54% and specificity 64% with a PPV of 91%. While CT scan had a sensitivity of 83% and a specificity of 45% with a PPV of 93%. Of the 4 patients with negative pathology and Alvarado score of ­>7 , 3 had CT scans positive for acute appendicitis and the remaining patient had a hemorrhagic ovarian cyst on laparoscopy.

Conclusions: We conclude that in patients with Alvarado score <7 the diagnosis of appendicitis cannot be excluded and thus warrant further diagnostic work up. CT scan is far more sensitive for acute appendicitis than ALVARADO score and is a reasonable next step in evaluating the patient with a low Alvarado score.  Furthermore, in patients with an Alvarado score of > 7 there is no benefit in obtaining radiographic confirmation as a high percentage of these patients will have acute appendicitis and appendectomy considered.