The global burden of appendicitis in the elderly
Globally, the prevalence of appendicitis in the elderly increased from 14,359.02 cases (95% UI: 9,615.09, 20,548.31) in 1990 to 34,625.50 cases (95% UI: 23,391.02, 48,800.78) in 2021. Among them, the number of cases in males rose from 6,587.87 (95% UI: 4,479.82, 9,348.14) to 15,878.91 (95% UI: 10,760.33, 22,366.72), and in females, it increased from 7,771.15 (95% UI: 5,138.45, 11,236.73) to 18,746.58 (95% UI: 12,621.85, 26,449.34) (Table 1). From 1990 to 2021, the age-standardized prevalence rate (ASPR) of appendicitis in the elderly (both male and female) increased by an average of 0.23% (95% CI: 0.16%, 0.30%) annually, while the ASPR for males and females increased by an average of 0.12% (95% CI: 0.05%, 0.19%) and 0.31% (95% CI: 0.24%, 0.39%) per year, respectively. In 2021, the incidence of appendicitis in the elderly was 907,091.16 cases (95% UI:622,501.85,127,098.78), of which 416,524.93 cases (95% UI:286677.07,582,307.61) were in males and 490,566.23 cases (95% UI:335712.61, 689735.61) (Table 1). Moreover, in 2021, the age-standardized incidence rate (ASIR) of appendicitis among the elderly was 82.18 cases per 100,000 population (95% UI: 56.51, 115.06), with ASIRs of 80.34 cases per 100,000 population (95% UI: 55.70, 111.80) for males and 83.91 cases per 100,000 population (95% UI: 57.32, 118.07) for females (Table 2). From 1990 to 2021, the ASIR increased by an average of 0.17% annually (95% CI: 0.10%, 0.24%). Similarly, the ASIR in women showed an average annual increase of 0.27% (95% CI: 0.20%, 0.34%), while the ASIR trend in men remained stable at 0.04% (95% CI: −0.04%, 0.11%) (Table 2). In 2021, appendicitis in the elderly resulted in 263,031.58 DALYs (95% UI: 223,586.99, 310,300.35) and 13,789.29 deaths (95% UI: 11,565.48, 16,305.01). Among these, appendicitis in elderly males caused 134,413.18 DALYs (95% UI: 112,931.28, 160,217.10) and 6,937.52 deaths (95% UI: 5,791.95, 8,329.81), while appendicitis in elderly females led to 128,618.40 DALYs (95% UI: 96,367.74, 163,923.44) and 6,851.77 deaths (95% UI: 5,022.73, 8,751.14) (Table 1). In 2021, the age-standardized DALYs rate (ASDR) and mortality rate (ASMR) for appendicitis in the elderly were 24.36 cases per 100,000 population (95% UI: 20.68, 28.74) and 1.31 cases per 100,000 population (95% UI: 1.10, 1.55), respectively (Table 2). It is noteworthy that, from a gender perspective, the burden of ASDR and ASMR is more severe in males than in females, but the average annual decline in ASDR and ASMR is more significant in males, with EAPC=−2.58% (95% CI: −2.64%, −2.51%) and EAPC=−2.49% (95% CI: −2.57%, −2.41%), respectively (Table 2). Over the past 32 years, the ASDR and ASMR burden of appendicitis has shown a declining trend among the elderly, regardless of gender (Table 2).
Regional burden of appendicitis in the elderly
In terms of the SDI regions, in 2021, the Middle SDI region had the highest number of prevalent cases and incident cases of appendicitis among the elderly population, with 10,276.07 cases (95% UI: 6,788.62, 14,734.97) and 269,152.90 cases (95% UI: 180,746.48, 383,716.59) respectively. During 2021, the Low-middle SDI region recorded the highest number of DALYs and Deaths, with 93,849.86 cases (95UI: 71,528.86, 121,762.12) and 4,785.15 cases (95UI: 3,614.82, 6,223.79) respectively (Table 1). Additionally, the ASPR and ASIR were highest in High SDI regions, while the ASDR and ASMR exhibited the highest levels in Low SDI regions (Table 2). From 1990 to 2021, the ASPR and ASIR of geriatric appendicitis showed an upward trend in High-middle SDI regions and Middle SDI regions. Meanwhile, ASDR and ASMR showed a general decline in most regions, with the most significant decrease observed in the High-middle SDI region, where the EAPCs for ASDR and ASMR were − 3.61% (95% CI: −3.74%, −3.48%) and − 3.60% (95% CI: −3.72%, −3.48%) respectively (Table 2).
National burden of geriatric appendicitis
At the national level, the People’s Republic of China ranked first in the absolute number of prevalence and incidence in 2021, while the Republic of India ranked first in the absolute number of DALYs and deaths (Table S1). The Republic of Colombia exhibited the highest ASPR (5.64 per 105 population, 95% UI: 4.48, 7.01) and ASIR (149.40 per 105 population, 95% UI: 119.50, 185.97), while the Republic of Honduras demonstrated the highest ASDR (144.21 per 105 population, 95% UI: 67.41, 248.83) and ASMR (7.86 per 105 population, 95% UI: 3.65, 13.49) (Table S2 and Fig. 1A and D). The State of Qatar exhibited the fastest increase in ASPR (EAPC = 3.47%, 95% CI: 3.35%, 3.59%) and ASIR (3.40%, 95% CI: 3.28%, 3.52%), while the Republic of Paraguay showed the most rapid rise in ASDR (EAPC = 1.31%, 95% CI: 1.01%, 1.62%) and ASMR (EAPC = 1.40%, 95% CI: 1.09%, 1.71%) (Table S2). In contrast, Ukraine’s ASPR (EAPC = −2.53%, 95% CI: −2.86%, −2.20%) and ASIR (EAPC = −2.55%, 95% CI: −2.89%, −2.22%), Republic of Kazakhstan’s ASDR (EAPC = −5.33%, 95% CI: −5.91%, −4.75%), and Arab Republic of Egypt’s ASMR (EAPC = −5.36%, 95% CI: −6.08%, −4.63%) showed the most significant average annual declines (Table S2 and Fig. 1E and H).
Geographic distribution of ASR and EAPC for appendicitis in the elderly aged 60 years and above across 204 countries and regions in 2021. (A) The ASPR in 2021 and (E) the trend from 1990 to 2021. (B) The ASIR in 2021 and (F) the trend from 1990 to 2021. (C) The ASDR in 2021 and (G) the trend from 1990 to 2021. (D) The ASMR in 2021 and (H) the trend from 1990 to 2021. Abbreviations: EAPC, Estimated Average Percentage Change; ASR, Age-Standardized Rate; ASDR, Age-Standardized Disability-Adjusted Life Year Rate; ASIR, Age-Standardized Incidence Rate; ASMR, Age-Standardized Mortality Rate
Age-sex-time association analysis of geriatric appendicitis
The sex-time correlation analysis revealed that the detailed trends of ASPR, ASIR, ASDR, and ASMR for appendicitis in males and females aged over 60 years globally and across five SDI regions over the past 32 years are depicted in (Fig. 2A and Figure S1A-1 C). For the High SDI region, the trends of ASPR and ASIR in both males and females tended to stabilize during the period from 1990 to 2021. In other regions, the ASPR and ASIR initially showed a declining trend over time, followed by an increasing trend. The ASDR and ASMR for both males and females in the global and five SDI regions have gradually decreased over time.
A. Temporal trends in age-standardized prevalence rate of appendicitis among the elderly population aged 60 years and above globally and in 5SDI regions from 1990 to 2021 (both, male and female). Age-sex trends in the burden of appendicitis among the elderly aged 60 and above in 2021 (B. Prevalence Number and rate C. Incidence Number and rate D. DALYs Number and rate E. Deaths Number and rate). Abbreviations: SDI: Sociodemographic Index. DALYs: Disability-Adjusted Life Years
The age-sex association analysis revealed that among the global population aged over 60 in 2021, the number of prevalent cases, incident cases, DALYs cases, and death cases in both males and females decreased with increasing age. Similarly, the prevalence and incidence rates in both males and females decrease with age. It is noteworthy that the DALYs rates and mortality rates for both males and females increase with age (Fig. 2B and E).
The age-period analysis revealed that the trends of ASPR, ASIR, ASDR, and ASMR for appendicitis among different age groups over 60 years old in the global and five SDI regions were similar from 1990 to 2021. With increasing age, the burden of ASPR and ASIR for appendicitis decreases, while the burden of ASDR and ASMR increases (FigureS2A-2D).
Association between geriatric appendicitis and SDI
At both the global and 21 GBD regional levels, the ASPR (r = 0.6676, p < 0.001) and ASIR (r = 0.6416, p < 0.001) of appendicitis in the elderly showed a positive correlation with SDI, increasing as SDI rose. The difference is that ASDR (r=−0.7296, p < 0.001) and ASMR (r=−0.7412, p < 0.001) are negatively correlated with SDI, decreasing as SDI increases. We observed that the observed values of ASPR, ASIR, ASDR, and ASMR in South Asia, Andean, and Central Latin America were higher than the SDI-based expectations from 1990 to 2021 (Fig. 3A and D). Among 204 countries and regions, ASPR (r = 0.6732, p < 0.001) and ASIR (r = 0.6420, p < 0.001) also increased with the growth of SDI. Consistent with previous trends, ASDR (r=−0.7131, p < 0.001) and ASMR (r=−0.7065, p < 0.001) also decreased with the decline in SDI. Furthermore, we found that the burden of geriatric appendicitis in certain countries such as Republic of Cuba, Republic of Colombia, and Republic of Honduras was higher than the predicted values (Fig. 3E and H).
Analysis of the trends in the burden of appendicitis among the elderly aged 60 and above in 21 GBD regions and 204 countries from 1990 to 2021 in relation to SDI changes. (A. ASPR in 21 GBD regions; B. ASIR in 21 GBD regions; C. ASDR in 21 GBD regions; D. ASMR in 21 GBD regions; E. ASPR in 204 countries; F. ASIR in 204 countries; G. ASDR in 204 countries; H. ASMR in 204 countries). Abbreviations: GBD: Global Burden of Disease. SDI: Sociodemographic Index. ASPR: Age-Standardized Prevalence Rate. ASIR: Age-Standardized Incidence Rate. ASDR: Age-Standardized DALYs (Disability-Adjusted Life Years) Rate. ASMR: Age-Standardized Mortality Rate
Decomposition analysis of appendicitis in the elderly
Through decomposition analysis, evaluate the impact of aging, population growth, and epidemiological changes on the prevalence, incidence, DALYs, and deaths of elderly appendicitis from 1990 to 2021. Overall, the prevalence and incidence of appendicitis in the elderly have shown an increasing trend globally and across all five SDI levels. However, in terms of DALYs and Deaths, High SDI and High-middle SDI show a downward trend. Population growth is the primary driver of Prevalence, Incidence, DALYs, and Deaths. Population growth contributes 91.34% to the global ASPR and has the largest contribution to the ASPR of Low SDI, at 108.24%. Epidemiological changes are a negative driver of DALYs and Deaths (Figure 3A-3D)(Table 3-S6).
Frontier analysis of appendicitis in the elderly
In a frontier analysis of elderly appendicitis across 204 countries and regions from 1990 to 2021 based on ASDR and SDI, varying trends have emerged. For DALYs, as the SDI value increased from 0.0 to 1.0, the ASDR showed a downward trend, characterized by a gradual shift from light blue (1990) to dark blue (2021), indicating a general decline in ASDR(Fig. 4A). Shifting the focus to the cutting-edge analytical results of 2021, visualize the disparities between countries and regions. In the ASDR analysis, countries such as Somalia, Niger, and Papua New Guinea are closer to the ideal baseline set by the border, indicating the optimal outcomes considering their SDI. Interestingly, only a few countries such as Mexico, Paraguay, and the Central African Republic have ASDRs that are on an upward trend and far from the border, while the rest of the countries are on a downward trend (Fig. 4B). Frontier analysis reveals the potential capabilities of different countries and regions in alleviating the burden of appendicitis.
The frontier analysis explores the relationship between SDI and the ASDR of appendicitis among the elderly population aged 60 and above in 204 countries: (A) The color gradient from dark blue (1990) to light blue (2021) represents the change over the years; (B) Each dot represents a specific country or region in 2021, with borders depicted in black, and the countries and regions with the longest and shortest distances from the frontier are labeled. The direction of change in age-standardized DALYs from 1990 to 2021 is indicated by the color of the dots, with red dots representing a decrease and blue dots representing an increase. Regression and Concentration Curves of Socio-demographic Index Inequality in DALYs Burden Due to Elderly Appendicitis in 1990 and 2021. Abbreviations: SDI, Socio-demographic Index; ASDR, Age-Standardized Disability-Adjusted Life Year Rate; DALYs: Disability-Adjusted Life Years
Health inequality analysis of appendicitis in the elderly
Analysis of 204 countries and regions worldwide revealed significant absolute and relative inequalities in the burden of disability caused by appendicitis in the elderly, in relation to SDI. From the inequality slope index, it can be observed that the gap in DALYs rates between the highest and lowest SDI countries and regions decreased from − 57.80 (95% CI: −66.75, −48.85) in 1990 to −39.93 (95% CI: −45.23, −34.63) in 2021. The concentration index decreased from − 0.24 (95% CI: −0.28, −0.21) in 1990 to −0.30 (95% CI: −0.33, −0.26) in 2021. The results showed that the absolute value of SII for the burden of disability caused by appendicitis in the elderly population decreased, indicating that the absolute gap between the poorest and wealthiest countries is narrowing; however, the absolute value of CII increased, meaning that the rate of improvement in poorer countries lags behind the global average, leading to an increasing concentration of the DALYs burden of appendicitis in low SDI countries. (Figure 4C and D).
Age-period cohort of elderly appendicitis
Figure 5 illustrates the impact of age, period, and birth cohort from the APC model on the prevalence, incidence, DALYs rate, and mortality of appendicitis among the global elderly population. Analysis of the age effect pattern reveals that as age increases, the prevalence and incidence rates of appendicitis in the overall population (regardless of gender) exhibit a similar declining trend, with the fastest rate of decline observed in the 65–75 age group. In contrast, the mortality rate of the overall population (regardless of gender) increases with age. Similarly, when stratified by gender, the trends in prevalence, incidence, and mortality rates among males and females exhibit the same characteristics as the corresponding indicators in the overall population (regardless of gender). It is noteworthy that the DALYs rate in women initially increases and then decreases with age, exhibiting a ‘W’ shaped pattern. The DALYs rate for males and the overall population (regardless of gender) showed an overall upward trend (Table S7, Figure S4-5). The period effect analysis indicates that, taking the year 2004.5 as the reference year, the overall elderly population (regardless of gender) exhibited relatively lower prevalence and incidence risk of appendicitis, both at the overall population level (regardless of gender) and from the perspectives of males and females. When using May 2004 as the reference point, the relative risks of DALYs and mortality for males, females, and the overall population (regardless of gender) were higher before this date, and subsequently decreased (Table S8, Figure S4-5). The birth cohort effect analysis indicates that, compared to the population born in 1927, the elderly groups born before this year exhibited higher relative risks in the prevalence, incidence, DALYs, and mortality of appendicitis; whereas those born after 1927 showed lower relative risks in DALYs and mortality. It is noteworthy that, when using the 1927 birth cohort as a reference, the prevalence and relative risk of appendicitis in females and the overall population were higher than in males, regardless of whether they were born before or after 1927, and exhibited a distinct fluctuation pattern. In contrast, the prevalence and incidence trends of appendicitis in males born after 1927 remained relatively stable (Table S9, Figure S4-5).
Age-period-cohort analysis results of appendicitis-related prevalence, incidence, DALYs, and mortality among the global population aged 60 years and above (overall population, regardless of gender) from 1990 to 2021 (A. Age effect on prevalence B. Age effect on incidence C. Age effect on DALYs D. Age effect on mortality E. Period effect on prevalence F. Period effect on incidence G. Period effect on DALYs H. Period effect on mortality I. Cohort effect on prevalence J. Cohort effect on incidence K. Cohort effect on DALYs L. Cohort effect on mortality). Abbreviations: DALYs: Disability-Adjusted Life Years
Predictive analysis of appendicitis in the elderly by 2050
The global ASR of appendicitis in the elderly aged 60 and above is expected to decline gradually from 2021 to 2050, with differing trends observed between males and females (Fig. 6). The ASPR for global geriatric appendicitis will gradually decline from 3.13 (95%UI: 2.12, 4.41) in 2021 to 3.02 (95%UI: 1.28, 4.76) in 2050. The ASPR for males is projected to be on an upward trend, increasing from 3.05 (95% UI: 2.08, 4.28) in 2021 to 3.28 (95% UI: 1.26, 5.31) in 2050, while the decline for females is expected to be more pronounced, decreasing from 3.21 (95% UI: 2.16, 4.53) in 2021 to 2.84 (95% UI: 1.10, 4.57) in 2050 (Table S10). Similarly, the ASIR of global geriatric appendicitis also decreased from 82.18 (95%UI: 56.51, 115.06) in 2021 to 78.85 (95%UI: 38.26, 119.44), with the trends in both males and females being similar to ASPR (Table S11). Both ASDR and ASMR have shown a slow decline, maintaining a downward trend in both males and females. The ASDR is projected to decrease from 24.36 (95% UI: 20.68, 28.74) in 2021 to 12.46 (95% UI: 4.78, 20.13) in 2050, and the ASMR is expected to decline from 1.31 (95% UI: 1.10, 1.55) in 2021 to 0.61 (95% UI: 0.33, 0.90) in 2050 (Table S12-13). This indicates that the ASR of appendicitis in the elderly will decline in the future, but attention should still be paid to the prevalence and incidence rates in males.
Trends and predictions of the global burden of appendicitis among individuals aged 60 years and older from 1990 to 2050, by sex. Lines represent trends, and columns represent numbers. (A) ASPR and prevalent cases of appendicitis in the elderly (B) ASIR and incident cases of appendicitis in the elderly (C) ASDR and the number of DALYs associated with appendicitis in the elderly (D) ASMR and the number of deaths associated with appendicitis in the elderly. Abbreviations: ASPR, age-standardized prevalence rate; ASIR, age-standardized incidence rate; DALYs, disability-adjusted life years; ASDR, age-standardized DALYs rate; ASMR, age-standardized mortality rate
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