Acute appendicitis: diagnostic accuracy of Alvarado scoring system

To evaluate the usefulness of the Alvarado scoring system in reducing the percentage of negative appendectomy in our unit.

A cross-sectional study was conducted, comprising 110 patients, admitted to Surgical Unit I, Civil Hospital, Karachi, in 2011 with a preliminary diagnosis of acute appendicitis. Patients of both sexes and all age groups except younger than 10 years were included in the study and their Alvarado scores calculated, on the basis of which patients were divided into two groups: Group A (Alvarado score <6) and Group B (Alvarado score ≥6). The signs, symptoms, laboratory values, surgical interventions, and pathology reports of each patient were evaluated. Diagnosis was confirmed by histopathological examination. Sensitivity, specificity, and positive and negative predictive values were calculated.

Out of 110 cases (79 males, 31 females), 31 belonged to Group A (28.2%) and 79 belonged to Group B (71.8%). Surgical procedures were performed in 98.2% of cases, along with conservative treatment. Final diagnosis by histopathology was confirmed in 77 cases (71.3%). The overall negative appendectomy rate was 28.7% (males: 28.2%, females: 30%). Sensitivity and specificity of the Alvarado scoring system were found to be 93.5% and 80.6% respectively. Positive and negative predictive values were 92.3% and 83.3%, respectively, and accuracy was 89.8%.

Alvarado score can be used effectively in our setup to reduce the incidence of negative appendectomies. However, its role in females was not satisfactory and needs to be supplemented by other means.