Diagnostic accuracy of ultrasonography and scoring systems: The effects on the negative appendectomy rate and gender

Despite the development of clinical, laboratory, and imaging methods, the diagnosis of acute appendicitis is not always easy, and negative appendectomy rates are still high. This study aims to reveal the effects of different scoring systems on the diagnostic accuracy of acute appendicitis and negative appendectomy rates, alone or when evaluated together with ultrasonography.

In this study, 202 consecutive patients who underwent emergency appendectomy for acute appendicitis were included. Clinical scores of all patients were preoperatively calculated using Ohmann, Raja Isteri Pengiran Anak Saleha Appendicitis (RIPASA), Lintula, Eskelinen, and Alvarado scoring systems. Abdominal ultrasonography (USG) was performed randomly in all cases. The sensitivity and specificity of scoring systems were calculated according to the threshold values. The area under the curve (AUC) was calculated using ROC analysis. In the regression model, histological diagnosis of appendicitis was used as the dependent variable, while scoring systems and USG were preferred as independent variables.

The negative appendectomy rate was 15.8%. In the diagnosis of acute appendicitis, Ohmann was the most predictive for both genders (DOR=24.2, 95% CI 6.98-84.44). Similarly, the lowest negative appendectomy rates were obtained with the Ohmann score as 6.9% in females and 3.4% in males. When the scores were combined with USG, the rate of diagnostic accuracy for acute appendicitis was not increased. However, when Ohmann and USG were combined, negative appendectomy rates were further reduced for women from 6.9% to 4%.

In addition to being a good diagnostic predictor of acute appendicitis in male and female patients, Ohmann score provides the best negative appendectomy rates. The combination of USG and scoring systems does not increase the diagnostic accuracy of acute appendicitis. However, negative appendectomy rates are significantly reduced when the USG and Ohmann scale are used together in females, while this reduction is minimal in men.