A Comparative Study of Alvarado Score with Abdominal Ultrasound for Preoperative Diagnosis of Acute Appendicitis

Background: Acute appendicitis is a common surgical emergency worldwide. Delayed diagnosis increases the risk of perforation and morbidity, while overdiagnosis results in unnecessary surgery. The Alvarado scoring system and abdominal ultrasonography (USG) are widely used to improve preoperative diagnostic accuracy. Aims and Objectives: To evaluate and compare the diagnostic performance of the Alvarado score and abdominal ultrasonography against histopathological examination as the gold standard in patients with suspected acute appendicitis. Methods: This prospective cross-sectional study was conducted at a tertiary care hospital in Uttarakhand, India, from April 2024 to November 2025. A total of 110 patients with suspected acute appendicitis were consecutively enrolled. All patients underwent clinical assessment, Alvarado scoring, laboratory investigations, and transabdominal ultrasonography. Diagnostic performance was assessed using histopathological findings. Statistical analysis was performed using SPSS version 20.0. Results: The mean patient age was 25.63 ± 11.45 years, with male predominance (55.45%). Histopathology confirmed acute appendicitis in 97 patients (88.18%), with a negative appendectomy rate of 11.82%. The Alvarado score demonstrated sensitivity, specificity, PPV, NPV, and accuracy of 83.51%, 92.31%, 98.78%, 42.86%, and 84.55%, respectively. Ultrasonography showed corresponding values of 81.44%, 84.62%, 97.53%, 37.93%, and 81.82%. Conclusion: Both diagnostic modalities demonstrated good diagnostic performance. The Alvarado score showed slightly higher specificity and overall accuracy than ultrasonography. Combining clinical scoring with targeted ultrasound assessment may improve diagnostic decision-making and reduce unnecessary appendectomies, particularly in resource-limited settings.