Comparing the Accuracy of Ohmann and Alvarado Scoring Systems in Detection of Acute Appendicitis; a Cross-Sectional Study.

Introduction Alvarado Scoring System (ASS) and Ohmann Scoring System (OSS) are two scoring systems for diagnosing acute appendicitis (AA). This study was designed to compare the diagnostic accuracy of the two mentioned scores in detection of acute abdominal cases at risk for AA. Methods In this prospective cross-sectional study, patients admitted to the emergency departments of two academic hospitals in Qom, Iran, with right lower quadrant (RLQ) abdominal pain suspected to AA were evaluated. All cases were scored using ASS and OSS, and screening performance characteristics of the two scores were calculated and reported considering the pathologic findings as a gold standard. Results 174 patients with a preliminary AA diagnosis and the mean age of 38.1 ± 10.63 years (11- 73) were included in this study (62.07% male). At the optimal cutoff point of ≥7 for the ASS, the sensitivity and the specificity were 46.43% (95% CI: 37.97%-55.07%), 97.05% (95% CI: 84.67%-92.93%), respectively. At the optimal cutoff point of ≥11 for the OSS, the sensitivity and the specificity were 74.29% (95% CI: 66.22%-81.29%), and 55.88% (95% CI: 37.89% - 72.82%), respectively. Conclusion Based on the finding of this study, the ASS ≥ 7 was more accurate than the OSS ≥ 11 for detection of AA. But it should be considered that the overall accuracy of Alvarado and Ohmann scores in this regard were fair (0.83) and poor (0.67), respectively.