Abstract
BACKGROUND: Acute appendicitis is a common surgical emergency worldwide, with significant variations in prevalence, presentation and outcomes between high-income countries (HIC) and low- and middle-income countries (LMIC). Complicated appendicitis has significant implications for low- and lower-middle-income countries due to limited healthcare resources. While there is extensive evidence for HICs, the evidence for low- and lower-middle-income countries is lacking. This systematic review aimed to compare the prevalence of complicated appendicitis between low-income countries (LICs) and lower-middle-income countries (LoMICs). METHODS: A systematic review was conducted following PRISMA guidelines (PROSPERO CRD42024526007). Observational studies and randomized controlled trials published in PubMed, MEDLINE, Embase and Scopus (1990-2024) were retrieved. A grey literature search of Google Scholar and the Cochrane Library was also performed to identify existing reviews on the topic. The primary outcome investigated was the incidence of complicated appendicitis. RESULTS: Eighty-seven articles with 25 582 participants were included. Meta-analyses of outcomes comparing LICs to LoMICs identified an increased pooled proportion of complicated appendicitis (34% (95% CI 27%-41%) vs. 23% (95% CI 19%-27%) P < 0.001), increased post-operative morbidity (19% (95% CI 13%-27%) vs. 13% (95% CI 8%-20%): P < 0.01) and mortality (OR 2.36). CONCLUSION: Appendicitis remains a major burden in LICs and LoMICs with higher rates of morbidity and mortality. These findings highlight critical deficiencies in surgical access and delivery, underscoring the need for targeted interventions to improve outcomes in these settings.