The Global Incidence of Appendicitis: A Systematic Review of Population-based Studies.

OBJECTIVE: We compared the incidence of appendicitis or appendectomy across the world and evaluated temporal trends.

SUMMARY BACKGROUND DATA: Population-based studies reported the incidence of appendicitis.

METHODS: We searched MEDLINE and EMBASE databases for population-based studies reporting the incidence of appendicitis or appendectomy. Time trends were explored using Poisson regression and reported as annual percent change (APC) with 95% confidence intervals (CI). APC were stratified by time periods and pooled using random effects models. Incidence since 2000 was pooled for regions in the Western world.

RESULTS: The search retrieved 10,247 citations with 120 studies reporting on the incidence of appendicitis or appendectomy. During the 21st century the pooled incidence of appendicitis or appendectomy (in per 100,000 person-years) was 100 (95% CI: 91, 110) in Northern America, and the estimated number of cases in 2015 was 378,614. The pooled incidence ranged from 105 in Eastern Europe to 151 in Western Europe. In Western countries, the incidence of appendectomy steadily decreased since 1990 (APC after 1989=-1.54; 95% CI: -2.22, -0.86), whereas the incidence of appendicitis stabilized (APC=-0.36; 95% CI: -0.97, 0.26) for both perforated (APC=0.95; 95% CI: -0.25, 2.17) and nonperforated appendicitis (APC=0.44; 95% CI: -0.84, 1.73). In the 21st century, the incidence of appendicitis or appendectomy is high in newly industrialized countries in Asia (South Korea pooled: 206), the Middle East (Turkey pooled: 160), and Southern America (Chile: 202).

CONCLUSIONS: Appendicitis is a global disease. The incidence of appendicitis is stable in most Western countries. Data from newly industrialized countries is sparse, but suggests that appendicitis is rising rapidly.