Lv T, et al. - In this systematic review and meta-analysis, researchers estimated the worldwide incidence and prevalence rates of autoimmune hepatitis (AIH) and reveal population difference. To pool the overall incidence and prevalence rates, a random-effects model was used. With subgroup analysis and meta-regression, the impact of population difference, gender, age, study period, study quality, diagnostic criteria, and study design was further analyzed. Data reported that the pooled worldwide annual incidence and prevalence of AIH were 1.37 and 17.44 per 100,000 persons, respectively. Subgroup analysis revealed that the pooled annual incidence for Asian, European, and American population was 1.31, 1.37, and 1.00 per 100,000 persons, respectively. It was noted that the pooled prevalence for Asian, European, and American population was 12.99, 19.44, and 22.80 per 100,000 persons, respectively. Furthermore, greater incidence and prevalence rates were noted in females compared to males, and a greater prevalence rate was observed in older individuals compared to young individuals. Overall, the authors concluded that AIH is a rare disease, with a comparable incidence worldwide and a higher prevalence in European and American than in the Asian population.