Alvarado or RIPASA score for diagnosis of acute appendicitis? A meta-analysis of randomized trials

Backround: The electronic diagnostic tools of acute appendicitis present serious disadvantages, thus some clinical scores have been formed in order to reach the diagnosis easily and safely. Alvarado and RIPASA scores are the most commonly used and the purpose of this meta-analysis is to compare the diagnostic accuracy of these two scoring systems. Method: We searched MEDLINE (1966-2017), Scopus (2004-2017), ClinicalTrials. gov (2008-2017), Google Scholar (2004-2017) and Cochrane Central Register of Controlled Trials CENTRAL (1999-2017) databases. We selected all observational cohort studies that reported diagnostic parameters of Alvarado and RIPASA diagnostic scores on patients with clinical status of acute appendicitis. Statistical meta-analysis was performed with Meta Disc 1.4 software. Results: Twelve studies were included in our meta-analysis which enrolled 2161 patients. The sensitivity of RIPASA score was 94% (95% CI, 92%-95%) and the specificity was 55% (95% CI, 51%-55%). In addition, the area under the Roc Curve (AUC) was 0.9431 and the diagnostic Odds Ratio was 24.66 (95% CI, 8.06 to 75.43). The sensitivity of Alvarado score was 69% (95% CI, 67%-71%) and the specificity was 77% (95% CI, 74%-80%). Moreover, the AUC was 0.7944 and the diagnostic Odds Ratio was 7.99 (95% CI, 4.75 to 13.43). Conclusion: RIPASA scoring system is more sensitive than Alvarado one, but the low specificity forms the need of a supplementary mean to provide the accurate diagnosis. Nevertheless, the wide and safe use of both tests is recommended in health systems that lack electronic diagnostic tests, such us developing countries or rural hospitals.