Introduction The clinical diagnostic scoring system for AA that combines history, symptoms, physical signs and laboratory indices, the Alvarado score, has sensitivity 82% and specificity 81%. The aim of this study was to determine the diagnostic accuracy of US for the diagnosis of AA.

Method A systematic search of literature from January 1994 to October 2014 was performed. The reference standard was pathology report on tissue obtained at surgery. Summary sensitivity, specificity and post-test probability of AA after positive and negative result of US with corresponding 95% confidence intervals (CI) were calculated. We used Review Manager and METADAS macro for SAS for statistical calculations.

Results Out of 3306 references identified through searches, 17 reports met the inclusion criteria, with 2841 participants. The sensitivity and specificity of US for diagnosis of AA were 69% (95% CI 59%–78%) and 81% (95% CI 73%–88%). At the median pretest probability of AA of 76.4%, the post-test probability for a positive and negative result of US was 92% (95% CI 88%–95%) and 55% (95% CI 46%–63%), respectively.

Conclusion US does not seem to have a role in the diagnostic pathway for diagnosis of AA in suspected patients. The summary sensitivity and specificity of US do not exceed that of physical examination. Patients that require additional diagnostic workup should be referred to more sensitive and specific diagnostic procedures, such as computed tomography.

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Disclosure of Interest None Declared