Background
Appendicitis is the most common abdominal surgical emergency worldwide, and it can lead to serious complications, such as ileus, peritonitis, abscess, and even death, as well as significant costs to the healthcare system [
1,
2]. The incidence of appendicitis is approximately 233 per 100,000 population per year, with a lifetime incidence risk ranging from 6.7 to 8.6% [
3,
4]. Although Western countries have reported a decrease in its incidence in the mid-twentieth century, newly industrialized countries have shown an increasing trend in the twenty-first century [
4‐
6]. With the increasing accuracy of acute appendicitis, ultrasound and computed tomography (CT) were the most common modalities and promote the use of antibiotics. For patients without high-risk CT findings, management of antibiotics first is suggested, and surgery can be recommended if antibiotic treatment fails [
7].
In 2018, World Health Organization (WHO) disclosed estimates of the cause-specific years of life lost (YLL), years lived with disability (YLD), and disability-adjusted life years (DALYs) for appendicitis stratified by cause, age, and sex at the global, regional, and country levels from 2000 to 2016 [
8]. However, no study addressing these data has been published. Recently, a systematic review reported the global incidence using data from population-based studies, but only some regional and country-level data were presented, and the burden in most countries around the world was unavailable [
9]. The latest study reported the global incidence and mortality from appendicitis using data from the (Global Burden of Disease Study) [GBD], but the 21 GBD regions and 204 countries were not analyzed in this study; in addition, prevalence and YLDs were unavailable from this study [
10]. Some national and regional studies have evaluated the incidence, prevalence, mortality, years of life lost (YLL), and DALY, however, there is no comprehensive, detailed data for all countries [
4,
9,
11‐
14]. To date, the incidence, prevalence, and YLD and association with the sociodemographic index (SDI) in all countries have not been analyzed. Therefore, a comprehensive, comparable analysis of the appendicitis burden is warranted to aid policy makers and healthcare providers in developing successful strategies to reduce the burden of appendicitis.
In the present study, we report the prevalence, incidence, and YLD of appendicitis in the general population in 204 countries and territories at the global, regional, and national levels in terms of the number and age-standardized rates stratified by age, sex, and SDI from 1990 to 2019.
Discussion
In the present study, we present the prevalence, incidence, and YLD and age-standardized rates for appendicitis in 204 countries and territories from 1990 to 2019. In 2019, there were 672,203 prevalent cases, 17,698,765 incident cases, and 211,113 YLD cases globally. The age-standardized prevalence, incidence, and YLDs rates were all increased from 1990 to 2019. To our best knowledge, the present study is the first to estimate the associations of age-standardized rates with the SDI in 21 GBD regions and 204 countries. The YLD rate of appendicitis increased with increasing SDI in terms of region and country.
Acute appendicitis is an acute condition, and it can lead to serious complications1,2, and some complications can lead to live in disability perpetually. Therefore, timely treatment can prevent serious complications. If hospital intraduct policies of prevent acute appendicitis, it can get faster treatment.
Appendicitis is one of the most common causes of abdominal pain in children and young adults, and occurs when the lumen of the vermiform appendix becomes inflamed, typically because of an obstruction. The condition can lead to death as well as significant costs to the healthcare system [
27]. In the United States, the cost of hospitalization related to appendicitis may be as high as $3 billion a year [
28]. The incidence of appendicitis is 7.8% [
29] and a 2017 study showed it has increased in western countries in 1900 and declined until the middle of the 20th [
4,
30]. However, the latest data show that the incidence of appendicitis has been on the rise and no complete and comprehensive study addressing these data has been published. Therefore, a comprehensive and comparable analysis of the burden of appendicitis must be performed to help decision makers and healthcare providers develop successful strategies to reduce the burden of appendicitis. In the present study, we report the prevalence, incidence, and YLDs of appendicitis in the general population in 204 countries and territories at the global, regional, and national levels in terms of the number and age-standardized rates stratified by age, sex, and SDI from 1990 to 2019.
GBD 2013 reported that the number of incident cases of appendicitis was 16 million in 2013 [
31] and increased to 19 million in 2017 [
32], whereas the number of incident cases was 17.7 million in 2019. The age-standardized incidence rate was 225.2 per 100,000 population in 2013 and 251.72 per 100,100 population in 2017, with a decrease of 14.58% from 1990 to 2013 and an increase of 1.8% from 1990 to 2017 [
31,
32]. In GBD 2019, the age-standardized incidence rate increased from 190.7 per 100,000 population in 1990 to 229.9 per 100,000 population in 2019, and the age-standardized incidence rate showed an increase of 20.5%. Similar to the incidence, the age-standardized prevalence and YLDs rates also showed decreasing and increasing trends from 1990 to 2013 and from 1990 to 2017, respectively [
31,
32]. Compared with GBD study, both the age-standardized prevalence and YLD rates showed an approximately tenfold increase from 1990 to 2019. This suggests that the burden of appendicitis increased over time, particularly from 2013 to 2019. However, number of incident cases in GBD 2019 was lower than that in GBD 2017. The results of these two studies could not be directly compared with our results, though, because of the different data sources and methodologies applied. For instance, GBD 2013 employed DisMod-MR 2.0, but GBD 2017 and GBD 2019 used DisMod-MR 2.1, to pool the available data. Moreover, compared with GBD 2017, GBD 2019 added subnational location data, such as Italy and Poland, and added estimates for the new locations (Monaco, San Marino, Cook Islands, and Saint Kitts and Nevis) [
15].
Most appendicitis studies focused on only specific regions or countries. Few have comprehensively investigated appendicitis at the regional and national levels globally. Although a previous publication reviewed the evolution of the global incidence of appendicitis during the twentieth century, data from most countries are unavailable [
9]. In the present study, we found that the highest age-standardized rates were more common in less-developed regions, such as Andean Latin America, Central Latin America, and Central Sub-Saharan Africa. This result was somewhat consistent with a previous review, which reported that the incidence in Asia, South America, and the Middle East was much higher than that in Western countries, and the incidence had increased in newly industrialized countries in the Middle East, South America, Asia, and Africa [
4,
5,
9,
11,
12]. At the country level, the present study found less-developed and developing countries, namely Bangladesh, Bhutan, and Peru, had the highest age-standardized incidence, prevalence, and YLD rates, were further confirmed the above findings. The above results suggest that the burden of appendicitis in less-developed and developing countries, particularly in newly industrialized countries, is higher than that in developed countries. The differences between regions and countries may be due to differences in healthcare systems, socioeconomic statuses of the population, race, eating habits, and environmental exposures [
4,
5,
9,
11,
12]. Therefore, prevention measures, management strategies and policies to reduce the burden of appendicitis should be given priority in these areas by policy makers.
Notably, the data in GBD 2019 were estimated using DisMod-MR 2.1 because only a few countries or territories provide actual population-based national data on the burden of appendicitis. Therefore, these national-level estimates should be interpreted with caution. If possible, additional attention should be given to health data collection to acquire representative data from every country. Additional resources are recommended to reduce the burden of appendicitis in low- and middle-income countries; thus, increased global cooperation might be necessary. These resources will contribute to more accurate predictions of the global burden of appendicitis and provide a basis for policy making.
As shown in previous studies [
5,
12], although the burden was slightly higher in female individuals in our study, no statistically significant difference was found in the prevalence and incidence rates between male and female individuals. Hence, both female and male individuals should be given equal priority in prevention and treatment policies. However, some studies showed that the incidence of appendicitis was higher in male than in female individuals, likely because of geographic variations [
4,
9,
12]. In 2019, the age-standardized prevalence, incidence, and YLD rates peaked in the 15- to 19-year age groups in both male and female individuals. These results were similar to those of a previous study that reported that the highest incidence was in the 15- to 19-year age group in female individuals and the 10- to 14-year age group in male individuals. Other studies confirmed this result and agreed that adolescents aged between 10 and 19 years had the highest burden of appendicitis [
4,
9,
12,
33].
To our best knowledge, the associations of the burden of appendicitis with the development levels of regions and countries have not been compared in previous studies. The present study found that the SDI was an important factor in the appendicitis burden, and a generally positive association was observed between the regional- and national-level SDI and YLD because of appendicitis from 1990 to 2019. Thus, the burden of appendicitis was generally lower in countries with higher socioeconomic development levels; however, the burden of appendicitis was not limited to either more-developed or less-developed regions or countries, because low burdens of appendicitis were observed in regions and countries with different SDI. This phenomenon could be attributed to an early accurate diagnosis and effective interventions, such as appendectomy and antibiotics. Countries with high socioeconomic development levels have better diagnostic tools and treatment facilities than those with low socioeconomic development levels [
11,
12]. The burdens of appendicitis were higher than the expected levels in some regions, such as Andean Latin America, Central Sub-Saharan Africa, Central Latin America, and High-income Asia Pacific, and other countries such as Andean Latin America, the Caribbean, and South Asia. When considering prevention policies, the observed burden should be combined with the expected burden based on the SDI in each region and country/territory.
Detecting and controlling risk factors are important approaches in prevention strategies. The risk factors for appendicitis include geographic and socioeconomic factors, race, seasonal patterns (the risk is highest in the summer), air pollution, dietary fiber, luminal obstruction, gastrointestinal infection, and genetic factors [
9,
33‐
38]. High temperatures in the summer, an important risk factor, must be considered in the development of regional- and national-level prevention programs, as well as global warming. In GBD 2019, risk factors for appendicitis such low fruit consumption, low vegetable consumption, education level and LDI were also evaluated in appendicitis mortality estimation [
15]. Thus, policymakers should consider those risk factors in their policy making.
Some limitations should be noted. First, the data included in the present study were secondary data from GBD 2019. The accuracy and robustness of GBD 2019 mainly depend on the quality and quantity of the input data used in the DisMod-MR 2.1 model. Second, the effects of different diagnosis, prevention strategies, and management policies in different regions and countries were not assessed, and substantial variations may exist, even in different regions and countries with the same SDI. Finally, because of the lack of relevant data, the burden of appendicitis stratified by histology was not evaluated in the present study.
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