Global burden and trends of appendicitis among adolescents and young adults: A systematic analysis for the Global Burden of Disease study 2021 and predictions to 2040.

Appendicitis is a prevalent abdominal disease with significant global distribution. This study aimed to assess the prevalence and burden of appendicitis by examining trends in incidence, mortality, and disability-adjusted life years (DALYs) from 1990 to 2021 among adolescents and young adults (AYAs). Data on appendicitis from the Global Burden of Disease database (1990-2021) were utilized. Point estimates with a 95% uncertainty interval (UI) were calculated to evaluate incidence rates, death rates, and DALY rates for individuals aged 15 to 39 years. Estimated annual percentage changes (EAPCs) were used to evaluate trends in age-standardized rates with a 95% confidence interval (CI). Future projections were generated using the Bayesian age-period-cohort model. In 2021, the global incidence of appendicitis among AYAs exceeded 10 million cases, with the highest incidence rate observed in the 20 to 24 age group. Incidence rates were higher among females. Between 1990 and 2021, the global incidence rate decreased from 391.46 (95% UI: 290.72-520.72) to 368.43 (95% UI: 279.00-488.48) per 100,000 population, with an EAPC of -0.27 (95% CI: -0.34--0.20). Death rates and DALY rates also showed declines, with EAPCs of -3.01 (95% CI: -3.23--2.78) and -2.59 (95% CI: -2.78--2.40), respectively. At the national level, India reported the highest number of cases in 2021 (2972,773.19; 95% UI: 2334,072.00-3778,073.13). The burden of appendicitis among AYAs decreased in most countries and territories, with the Republic of Armenia showing the most notable reduction in death rates from 1990 to 2021. Regional analyses indicated that high-middle socio-demographic Index (SDI) regions had the highest incidence rates in 2021, while most SDI regions experienced declining trends in death and DALY rates over the study period. Projections using the Bayesian age-period-cohort prediction model suggest that the incidence and DALY rates of appendicitis among AYAs will continue to decrease from 2021 to 2040. Appendicitis remains a substantial public health burden among AYAs due to its high incidence. Despite significant global declines in deaths and DALYs, the absolute numbers of deaths and DALYs remain substantial, particularly in low-middle and low SDI regions. Effective and targeted medical and health policies are essential to reduce the burden of appendicitis in AYAs.