A systematic review and meta-regression for validation of the Alvarado score as a tool for predicting acute appendicitis

Abstract

Background: The Alvarado score (AS) has not been widely used for diagnosing acute appendicitis although it has shown to be a good predictor for diagnosing appendicitis. The aim was to perform a systematic review of the available literature and synthesize the evidence. Methods: A systematic review was performed as per the PRISMA guidelines using search engines like Ovid, PubMed, and Google Scholar with predefined, strict inclusion and exclusion criteria. The quality assessment of included studies was performed using the QUADAS 2 tool. Summary statistics were performed for all variables. A linear regression model was performed between dependent and independent variables using STATA software. Heterogeneity testing showed significant heterogeneity within the included studies; hence, a forest plot with pooled estimates could not be constructed, and therefore a meta-regression was performed. Results: Seventeen full-text articles met inclusion and exclusion criteria. Ten of which were identified as low-risk studies. Five studies were included in final data pooling with total patients being 2239 and mean age of 31.9 years. (1) Linear regression demonstrated an association between 'histological appendicitis' and 'AS 7-0' with patients receiving intervention, with a significant P value of less than 0.005. (2) Meta-regression demonstrated a positive coefficient (0.298), a positive Z score of 2.20 with a significant P value of 0.028 for patients with 'high AS' who received interventions that were significantly proven to be 'histologically appendicitis', indicating a cause-and-effect relationship. Conclusion: High AS (7 and above) is a significant predictor of acute appendicitis. The authors recommend further prospective randomized clinical trials to establish a cause-and-effect relationship.