A simplified appendicitis score in the diagnosis of acute appendicitis

Introduction: Scoring systems such as the Modified Alvarado Score (MAS) can help in the early diagnosis of acute appendicitis (AA) but is cumbersome to use and has not found widespread popularity. A more robust, user-friendly Simplified Appendicitis Score (SAS) was investigated. Methods: Patients presenting with suspected AA were prospectively enrolled. The performance of the SAS (using only 5 variables - migratory pain, right lower quadrant tenderness, rebound pain, fever >37.3 degrees Celsius and leucocytosis >12,000/uL) was analysed and compared to the MAS. Results: Out of 238 patients enrolled over four months, 95 (39.9%) patients underwent appendectomy, of which 81 patients had histologically proven AA. A MAS of >= 8 was 92.4% specific for ruling in AA, while a score of <5 was 91.4% sensitive in ruling out AA. A SAS of >= 6 was 91.7% specific for ruling in AA, while a score of <4 was 90.1% sensitive in ruling out AA. Conclusions: The performance of the MAS can be maintained by omitting the two subjective variables - "anorexia" and "nausea/vomiting", and increasing the leucocytosis cut-off level. A SAS using only 5 variables performed as well as the original MAS. (Hong Kong j.emerg.med. 2010;17:230-235)