Divergent trajectories of inflammatory bowel disease in East, South, South-East and Central Asia: A comprehensive GBD 2021 analysis

Abstract

Background

Inflammatory bowel disease (IBD) is no longer confined to Western populations; its burden is rising across Asia, a region with marked demographic, economic, and health-system heterogeneity. Quantifying contemporary trends and their drivers is essential for region-tailored policy. We aimed to provide the first continent-wide, methodologically harmonized assessment of temporal trends, demographic–epidemiologic determinants, and projections of IBD burden in Asia.

Methods

We extracted country-specific incidence, prevalence, mortality, and disability-adjusted life-years (DALYs) for 1990–2021 from the Global Burden of Disease 2021 for 43 Asian countries/territories. Age-standardized rates (ASRs) were summarized using estimated annual percentage change (EAPC). An additive Das-Gupta decomposition apportioned absolute changes in cases and DALYs to population growth, population ageing, and epidemiologic change. Bayesian age–period–cohort models projected burden to 2040.

Results

From 1990 to 2021, prevalent IBD cases more than doubled (0.54 million→1.34 million) and incident cases nearly tripled. Age-standardized prevalence (ASPR) and incidence (ASIR) rose by 25 % (EAPC 0.98 %) and 34 % (EAPC 1.17 %), respectively. In contrast, the age-standardized death rate declined from 0.50 to 0.30 per 100 000 (EAPC –1.97 %), and the DALY rate fell by 32 % (16.1 → 11.0 per 100 000; EAPC –1.30 %). Decomposition attributed 56 % of additional prevalent cases to population growth, 20 % to ageing, and 24 % to rising age-specific rates. East Asia showed the fastest proportional rise in ASIR yet the steepest DALY decline; Central Asia maintained the highest per-capita disability load; and Southeast Asia remained a low-burden plateau. Projections indicate continued prevalence growth in South and Central Asia, epidemiologic stabilization in East Asia, and sustained low burden in Southeast Asia by 2040.

Conclusions

Asia is experiencing a dual dynamic of expanding IBD caseload alongside improving survival and disability outcomes, with pronounced sub-regional heterogeneity. Demography remains the principal driver of case growth, but genuine increases in age-specific incidence signal ongoing propagation of risk. Strengthening surveillance, expanding equitable access to advanced therapies, and implementing region-specific, longitudinal care pathways are imperative to avert disproportionate future disability and economic loss.

1. Introduction

Inflammatory bowel disease (IBD)—encompassing Crohn's disease and ulcerative colitis—has transitioned from a predominantly Western disorder to a global chronic condition undergoing rapid geographic redistribution [1]. Asia, home to more than half of the world's population and marked by pronounced socio-economic, demographic, and environmental heterogeneity, is now traversing the early and intermediate phases of this epidemiological shift [2]. Accelerated industrialisation, urbanisation, westernisation of diet, antibiotic exposure, and improved sanitation have altered the intestinal exposome, plausibly unmasking IBD susceptibility in genetically diverse populations [[3], [4], [5], [6]]. Concomitantly, population ageing and expanding diagnostic capacity are poised to amplify the future clinical and economic footprint of IBD across the region [7,8].

Despite escalating signals from higher-income settings (e.g. Japan, South Korea, urban China) [9], the true scale, trajectory, and internal diversity of the IBD burden across much of Asia remain poorly delineated. Fragmented hospital-based series, under-resourced surveillance in low- and middle-income countries, inconsistent case definitions, and differential access to endoscopy and biologic therapy impede valid inter-country comparison and strategic planning [10]. Critically, few studies have: (1) synthesised incidence, prevalence, mortality, and disability-adjusted life years (DALYs) using a uniform methodological platform across all Asian sub-regions; (2) decomposed temporal changes into demographic (population growth and ageing) versus epidemiological (risk and case-fatality) components; and (3) generated probabilistic forecasts to anticipate health-system demand. These evidence gaps constrain rational allocation of finite resources for early diagnosis, advanced therapeutics, and long-term multidisciplinary care [11].

Leveraging the Global Burden of Disease (GBD) 2021 framework [12]—an internally consistent, Bayesian, and comparably standardised estimation system—we provide the first continent-wide, country-resolved assessment of IBD burden spanning 43 Asian countries and territories over three decades (1990–2021), coupled with demographic-epidemiological decomposition and Bayesian projections to 2040. By integrating incidence, prevalence, mortality, and DALYs within a single analytical architecture, we characterise stage of epidemic maturation across sub-regions (Central, East, South, and South-East Asia), quantify sex- and age-specific profiles, isolate the relative contributions of population ageing versus changing disease dynamics, and delineate plausible future caseload envelopes under uncertainty [13]. This comprehensive approach delivers policy-relevant intelligence to: (1) prioritise capacity building where rapid expansion is projected (e.g. South Asia), (2) consolidate chronic care infrastructure where plateaus are emerging (e.g. South-East Asia), and (3) sustain disability and mortality gains in settings with declining burdens (e.g. East Asia). Ultimately, our work fills a critical evidentiary void by supplying harmonized, forward-looking metrics needed to inform strategic planning, equitable resource distribution, and evaluation of interventions aimed at mitigating the burgeoning impact of IBD across Asia.

2. Methods

2.1. Data sources

This study was based on data from the Global Burden of Disease Study 2021 (GBD 2021), a comprehensive initiative led by the Institute for Health Metrics and Evaluation (IHME), which provides systematically comparable estimates of disease burden across countries, years, and demographic groups [14]. We extracted country-specific data related to IBD, including both ulcerative colitis and Crohn's disease, for 43 Asian countries and territories: Lebanon, Bhutan, the Philippines, Armenia, India, Uzbekistan, Azerbaijan, Sri Lanka, Thailand, Nepal, Bahrain, United Arab Emirates, Pakistan, Israel, Cambodia, Timor-Leste, Singapore, Iran (Islamic Republic of), Qatar, Cyprus, Oman, Georgia, Kazakhstan, Viet Nam, Yemen, Lao People's Democratic Republic, Kyrgyzstan, Malaysia, Afghanistan, Indonesia, Iraq, China, Saudi Arabia, Maldives, Kuwait, Türkiye, Syrian Arab Republic, Tajikistan, Jordan, Myanmar, Turkmenistan, Democratic People's Republic of Korea, and Bangladesh.

We extracted annual estimates from 1990 to 2021 for four key indicators of IBD burden: incidence, prevalence, mortality, and disability-adjusted life years (DALYs). For each metric, both the crude counts and age-standardized rates (ASRs, per 100 000 population) were obtained to enable cross-country and temporal comparisons. Age standardization was performed using the GBD world standard population. All data were retrieved from the publicly accessible GBD Results Tool (https://vizhub.healthdata.org/gbd-results/), ensuring consistency in definitions and estimation methodology across countries and years.

To evaluate temporal trends in the age-standardized rates (ASRs) of IBD incidence, mortality, DALYs, and prevalence from 1990 to 2021, we calculated the Estimated Annual Percentage Change (EAPC) for each indicator [15]. EAPCs were derived from a linear regression model fitted to the natural logarithm of the ASR values over time. The 95 % confidence interval (CI) of the EAPC was computed to assess the statistical significance of the trend. An ASR was considered to have an increasing trend if both the EAPC and the lower bound of its 95 % CI were greater than zero, and a decreasing trend if both the EAPC and the upper bound of its 95 % CI were less than zero; otherwise, the trend was classified as stable. This approach provided a consistent and interpretable measure of the direction and magnitude of disease burden trends across diverse Asian settings [16].

2.2. Decomposition of change in absolute burden

To clarify the forces driving the rise in incident cases, prevalent cases, deaths, and DALYs, we conducted an additive decomposition based on the framework proposed by Das Gupta [17]. For every country, we compared the 1990 and 2021 counts and apportioned the net difference into three mutually exclusive components. The first component reflects population growth—the additional burden that would have arisen solely from a larger population if age structure and age-specific IBD rates had remained unchanged. The second captures population ageing, that is, shifts in the age distribution that move more people into groups at higher baseline risk, independent of changes in overall population size or disease rates. The third component represents epidemiologic change—the portion of the difference attributable to gains or losses in age-specific IBD rates themselves, after adjusting for both population growth and ageing. Country-specific results were then aggregated to sub-regional and continental totals using population-weighted averages.

Uncertainty intervals for each component were derived by repeatedly sampling (1000 draws) from the posterior distributions of the age-specific rates supplied by the GBD study and re-running the decomposition on each draw. All calculations were performed in R (package DemoDecomp).

2.3. Projection of future trends

To project future trends in IBD burden, we employed a Bayesian age-period-cohort (BAPC) model, incorporating integrated nested Laplace approximations (INLA) [18]. The BAPC model is designed to account for temporal changes in disease patterns driven by age structure, calendar period effects, and birth cohort influences [19,20]. The modeling was performed using the R package BAPC, following established methodologies validated in previous global burden studies. Projections were made beyond 2021 to support long-term public health planning.

2.4. Statistical tools

All statistical analyses and data visualizations were conducted using R software (Version 4.2.2; R Foundation for Statistical Computing, Vienna, Austria). The Health Equity Assessment Toolkit (HEAT) developed by the World Health Organization was additionally utilized to explore equity-related patterns in the data [21].

2.5. Ethics statement

This research was based exclusively on publicly available, anonymized secondary data and was therefore exempt from institutional ethics review.

3. Results

3.1. Regional trends in the burden of inflammatory bowel disease in Asia

Between 1990 and 2021, the burden of IBD in Asia increased substantially in terms of prevalence and incidence, while mortality and disability-adjusted life years (DALYs) generally declined across regions (Fig. 1).

Fig. 1.

Trends in inflammatory bowel disease (IBD) burden across Central Asia, East Asia, South Asia, Southeast Asia, Asia (overall), and the global aggregate, 1990–2021. showing age-standardized prevalence, incidence, mortality, and DALY rates per 100 000.

3.2. Prevalence

In 2021, the total number of prevalent IBD cases in Asia reached approximately 1.34 million (95 % uncertainty interval [UI]: 1.14–1.62 million), up from 541 174.3 (458 133.4–655 497.6) in 1990. The age-standardized prevalence rate (ASPR) increased from 20.9 to 26.1 per 100 000 population, with a corresponding EAPC of 0.98 (95 % CI: 0.83 to 1.14). East Asia exhibited the most pronounced increase in ASPR, rising from 5.6 to 9.1 per 100 000 (EAPC: 2.49; 95 % CI: 1.87 to 3.11), while Central Asia maintained relatively stable rates with an EAPC of 0.04 (95 % CI: −0.02 to 0.11). South Asia also demonstrated a notable increase (EAPC: 0.73; 95 % CI: 0.63 to 0.83). In contrast, the global ASPR slightly declined (EAPC: −0.13; 95 % CI: −0.25 to 0), despite increases in case numbers(Table 1).

Table 1.

Burden of inflammatory bowel disease (IBD) in Asia and subregions, 1990 and 2021. The table reports counts (“Number”) and age-standardized rates (ASR, per 100 000) for prevalence (ASPR), incidence (ASIR), mortality (ASMR), and disability-adjusted life years (DALY rate), alongside the estimated annual percentage change (EAPC, 1990–2021) with 95 % confidence intervals.

	location	Number 1990	ASR 1990	Number 2021	ASR 2021	EAPC_95 %CI
Prevalence	Asia	541174.3 (458133.4–655497.6)	20.9 (17.9–25.1)	1343768.5 (1141496–1622068.6)	26.1 (22.3–31.5)	0.98 (0.83–1.14)
	Central Asia	25296.8 (21390.4–30480.2)	46.2 (39–55.9)	44278 (37278.8–53731.9)	45.6 (38.6–55)	0.04 (−0.02 to 0.11)
	East Asia	64806.6 (54671.1–78247)	5.6 (4.8–6.7)	172201.1 (145042.9–206864.1)	9.1 (7.7–10.9)	2.49 (1.87–3.11)
	Global	2170243.3 (1892401.8–2522561.3)	48 (41.9–55.8)	3830119.3 (3312834–4511554.5)	44.9 (38.8–52.9)	−0.13 (−0.25 to 0)
	South Asia	301260.8 (253265.9–365312)	38.9 (33–46.9)	802535.7 (676699.5–975730.6)	46.2 (39.2–55.7)	0.73 (0.63–0.83)
	Southeast Asia	20947.4 (17481.2–25166.5)	5.6 (4.7–6.6)	42506.4 (35567.2–51597.2)	5.7 (4.8–6.9)	0.17 (0.12–0.21)
Incidence	Asia	64440.6 (55365.4–77599.2)	2.4 (2.1–2.9)	164462.9 (142134.9–197627.7)	3.2 (2.8–3.9)	1.17 (1.05–1.3)
	Central Asia	2523.7 (2178.1–3067)	4.4 (3.8–5.3)	5017.7 (4317.5–6101.3)	5.2 (4.5–6.2)	0.5 (0.47–0.53)
	East Asia	8632.7 (7283.5–10588.2)	0.7 (0.6–0.9)	25532.2 (22107.4–30529.7)	1.4 (1.2–1.7)	2.88 (2.37–3.4)
	Global	199235.9 (174583.8–232676.2)	4.2 (3.7–4.9)	375139.7 (327686.2–436925.1)	4.4 (3.9–5.2)	0.29 (0.2–0.38)
	South Asia	40231 (34456–48839.8)	5 (4.3–6)	106215.5 (91604.6–128246.9)	6 (5.2–7.2)	0.66 (0.58–0.74)
	Southeast Asia	2268.2 (1922.3–2797.8)	0.6 (0.5–0.7)	5035.2 (4271.3–6181.2)	0.7 (0.6–0.8)	0.51 (0.47–0.55)
Deaths	Asia	9104.5 (6551.3–10955.3)	0.5 (0.4–0.6)	13659.5 (11405–16943.4)	0.3 (0.3–0.4)	−1.97 (−2.1 to −1.83)
	Central Asia	199.3 (182–217.7)	0.4 (0.3–0.4)	258.8 (222.3–301.3)	0.3 (0.3–0.4)	−1.03 (−1.26 to −0.8)
	East Asia	4592.1 (3149.1–5757.7)	0.7 (0.5–0.9)	5967.1 (4700.2–7910.3)	0.3 (0.3–0.4)	−3.01 (−3.35 to −2.66)
	Global	21417.7 (18422.8–23612.6)	0.6 (0.5–0.7)	42422.7 (37536.9–46502.1)	0.5 (0.5–0.6)	−0.31 (−0.48 to −0.14)
	South Asia	2744.7 (1904.9–3527.7)	0.5 (0.3–0.6)	4717.6 (3511.3–6287.9)	0.3 (0.3–0.5)	−1.21 (−1.31 to −1.1)
	Southeast Asia	769.8 (423.4–1079.9)	0.3 (0.2–0.5)	1235.8 (887.9–1469.6)	0.2 (0.2–0.3)	−1.61 (−1.75 to −1.48)
Disability-adjusted life years	Asia	394911.4 (311773.7–470652.4)	16.1 (12.5–19)	541310.6 (444053.9–660283)	11 (9.1–13.3)	−1.3 (−1.36 to −1.25)
	Central Asia	13065.6 (10958.4–15114.5)	21.4 (18.4–24.7)	17039.2 (14248.8–20607.1)	17.9 (15–21.6)	−0.83 (−0.97 to −0.68)
	East Asia	167496.3 (120085.3–212704.4)	18.3 (12.8–23)	143568.6 (116156.1–180090.7)	7.8 (6.3–9.6)	−2.89 (−3.16 to −2.62)
	Global	948860.8 (808100.6–1096717)	21.5 (18.5–24.8)	1510783.8 (1308507.8–1750363.2)	18.1 (15.7–20.9)	−0.52 (−0.6 to −0.43)
	South Asia	146278.7 (114030–186335.1)	19.5 (15–24.3)	269363.4 (211770.3–341920.9)	16.1 (12.7–20.4)	−0.64 (−0.7 to −0.58)
	Southeast Asia	28473.2 (17974.4–36114.3)	8.8 (5.3–11.8)	40665.3 (30950.1–47973.5)	6.1 (4.6–7.2)	−1.42 (−1.53 to −1.31)

3.3. Incidence

The number of new IBD cases in Asia increased from 64 440.6 (55 365.4–77,599.2) in 1990 to 164 462.9 (142 134.9–197 627.7) in 2021, with an increase in the age-standardized incidence rate (ASIR) from 2.4 to 3.2 per 100 000 population. The corresponding EAPC was 1.17 (95 % CI: 1.05 to 1.3), indicating a consistent upward trend. East Asia experienced the fastest rise in ASIR (EAPC: 2.88; 95 % CI: 2.37 to 3.4), doubling its rate from 0.7 to 1.4 per 100 000. Other subregions such as South Asia and Southeast Asia showed more modest but significant increases (EAPCs of 0.66 and 0.51, respectively). Globally, ASIR increased slightly (EAPC: 0.29; 95 % CI: 0.2 to 0.38) (Table 1).

3.4. Mortality

IBD-related mortality in Asia rose in absolute terms—from 9104.5 (6551.3–10,955.3) deaths in 1990 to 13 659.5 (11 405–16,943.4) in 2021—yet the age-standardized death rate (ASDR) decreased from 0.5 to 0.3 per 100 000, reflecting a significant decline (EAPC: −1.97; 95 % CI: −2.1 to −1.83). The largest reductions were observed in East Asia (EAPC: −3.01; 95 % CI: −3.35 to −2.66), while Southeast and South Asia also showed decreasing trends (EAPCs: −1.61 and −1.21, respectively). The global ASDR declined slightly (EAPC: −0.31; 95 % CI: −0.48 to −0.14) (Table 1).

3.5. Disability-adjusted life years (DALYs)

The total DALYs attributable to IBD in Asia increased from 394 911.4 (311 773.7–470 652.4) to 541 310.6 (444 053.9–660 283), while the age-standardized DALY rate declined from 16.1 to 11.0 per 100 000 (EAPC: −1.3; 95 % CI: −1.36 to −1.25). East Asia experienced the steepest decline in DALY rate (EAPC: −2.89; 95 % CI: −3.16 to −2.62), followed by Southeast Asia (EAPC: −1.42; 95 % CI: −1.53 to −1.31). Central and South Asia also exhibited moderate reductions (EAPCs: −0.83 and −0.64, respectively). At the global level, the age-standardized DALY rate declined modestly (EAPC: −0.52; 95 % CI: −0.6 to −0.43), despite an overall increase in DALY numbers (Table 1).

3.6. Clinical implications

Incidence and prevalence are still climbing—especially in South and East Asia (South Asia prevalence 38.9 → 46.2 per 100 000)—reflecting urbanisation, westernised diets, microbiome shifts, and better diagnostics. Larger survivor cohorts are increasing demand for endoscopy, biologics, and coordinated care, even as mortality and DALY rates fall. Central and South Asia retain the heaviest burdens, highlighting gaps in specialist access and advanced therapy. Strategic priorities are capacity expansion, equitable biologic procurement, context-adapted guidelines, patient education, and stronger surveillance to narrow regional disparities.

3.7. Country-specific patterns in IBD burden, 1990–2021

Below we summarize the principal national trajectories in age-standardised prevalence, incidence, mortality, and DALY rates for the 43 Asian countries and territories included in GBD 2021 (Table 2). Unless otherwise stated, all values refer to rates per 100 000 population in 2021; figures in parentheses denote the estimated annual percentage change (EAPC, 1990–2021).

Table 2.

Country-specific burden of inflammatory bowel disease (IBD) in Asia, 2021, with temporal trends (1990–2021). For each of the 43 countries/territories, the table reports age-standardized rates (ASR, per 100 000) for prevalence (ASPR), incidence (ASIR), mortality (ASMR), and disability-adjusted life years (DALY rate), together with the estimated annual percentage change (EAPC) and its 95 % confidence interval. ASRs are standardized to the GBD world standard population; values are for both sexes combined unless otherwise noted. An increasing (decreasing) trend is inferred when the EAPC and its 95 % CI are entirely above (below) zero; otherwise the trend is classified as stable.

	location	Number 1990	ASR 1990	Number 2021	ASR 2021	EAPC_95 %CI
Prevalence
	Afghanistan	1396.8 (1156.9–1689.9)	19.4 (15.9–23.5)	4550.4 (3748.9–5528.4)	23.2 (19.3–28.3)	0.83 (0.67–0.99)
	Armenia	1512 (1268.1–1828.9)	48.1 (40.3–58.2)	1919.9 (1611.2–2348.2)	51 (42.7–62.1)	0.28 (0.25–0.3)
	Azerbaijan	2780.1 (2328.7–3350.1)	46 (39–55.4)	6160.4 (5068.7–7553.7)	50.7 (42.5–61.5)	0.42 (0.27–0.57)
	Bahrain	128.6 (108–154.8)	29.6 (25.2–35.1)	584.2 (483.7–710.4)	32.7 (27.7–39.3)	0.73 (0.59–0.87)
	Bangladesh	28648.1 (23828.8–34666.4)	41.9 (35.3–50.5)	79568.6 (67287.5–97266.9)	50 (42.2–60.9)	0.79 (0.71–0.88)
	Bhutan	153.4 (126.4–184.6)	39.1 (32.7–47.1)	339.2 (283.8–409.1)	45 (37.7–54)	0.58 (0.5–0.65)
	Cambodia	330.2 (273–400.2)	4.5 (3.7–5.4)	754.3 (627.5–923.4)	4.6 (3.8–5.6)	0.13 (0.09–0.18)
	China	62097.9 (52445.9–75050.2)	5.6 (4.7–6.7)	168076.7 (141521.2–201684.4)	9.2 (7.8–11)	2.54 (1.91–3.17)
	Cyprus	766.5 (647–950.4)	93.4 (78.8–116)	2002.2 (1704.1–2424.5)	113.6 (96.5–137)	0.67 (0.58–0.75)
	Democratic People's Republic of Korea	1345.5 (1130.2–1635.7)	6.6 (5.6–8.1)	1947.7 (1635.7–2341.9)	6.2 (5.2–7.4)	−0.07 (−0.13 to −0.01)
	Georgia	3097.3 (2598.8–3760.5)	51.2 (43–62.2)	2425.5 (2069.8–2952.8)	52 (44–63)	0.11 (0.03–0.2)
	India	241010.2 (202522.2–293995.8)	38.7 (32.9–46.7)	642357.4 (541442.7–781038.4)	46.7 (39.6–56.4)	0.78 (0.66–0.9)
	Indonesia	8601.3 (7210.2–10338.9)	5.8 (4.9–6.9)	17041.8 (14142.1–20704.1)	5.7 (4.8–6.9)	−0.08 (−0.13 to −0.03)
	Iran (Islamic Republic of)	12076.1 (10025–14986.3)	33.6 (28–41.9)	31788.9 (26328.5–39171.8)	33.7 (28.2–41.2)	0.58 (0.27–0.88)
	Iraq	2384.1 (2012.7–2859.6)	19.5 (16.6–23.4)	9879.9 (8105.4–12071)	27 (22.1–32.7)	1.11 (0.98–1.23)
	Israel	5902.3 (4993.7–7016)	127 (106.9–151)	13653.2 (11490.4–16380)	136.5 (114.7–164)	−0.53 (−1.08 to 0.03)
	Jordan	898.4 (761.7–1053.7)	39.3 (33.4–45.7)	4925.8 (4127.6–6005.8)	44 (37.1–53.3)	0.78 (0.6–0.96)
	Kazakhstan	7134.8 (5981.6–8738.5)	48.8 (41.1–60.1)	9825.6 (8257.4–11937.9)	49.1 (41.5–59.6)	0.09 (−0.02 to 0.19)
	Kuwait	672.7 (589.3–771.7)	44.6 (39.5–50.3)	2372.7 (1937.1–2942.7)	41.5 (34.5–50.4)	−0.39 (−0.76 to −0.02)
	Kyrgyzstan	1501.8 (1263.8–1834.6)	43.9 (37.1–53.8)	2843.9 (2406.4–3483.9)	46.1 (39.3–56)	0.1 (0–0.2)
	Lao People's Democratic Republic	138.7 (113.6–169.5)	4.5 (3.7–5.5)	347.3 (282.7–426.4)	5 (4.1–6.1)	0.47 (0.41–0.53)
	Lebanon	2128.7 (1778.8–2598.4)	83.7 (69.7–102.3)	6002.7 (5031.3–7352.8)	99.1 (83.1–121.2)	0.71 (0.62–0.8)
	Malaysia	991.6 (839.6–1196.2)	6.8 (5.8–8.1)	2805.6 (2328.3–3382.7)	8.3 (6.9–9.9)	1.31 (1–1.62)
	Maldives	7.7 (6.4–9.4)	5.2 (4.3–6.3)	39.3 (31.6–49.2)	6.5 (5.4–7.9)	0.6 (0.52–0.67)
	Myanmar	1550.5 (1279.1–1886.1)	4.6 (3.8–5.6)	2845.4 (2357–3490)	5 (4.1–6.1)	0.45 (0.38–0.51)
	Nepal	5292.2 (4392.6–6364.9)	39.7 (33.2–47.7)	12410.1 (10191–15292.1)	44.4 (36.6–54.6)	0.38 (0.35–0.42)
	Oman	396.3 (326.5–480.8)	28.5 (23.6–34.4)	1798.1 (1470–2214.2)	37.4 (31.3–45)	1.18 (1.01–1.36)
	Pakistan	26156.9 (22077.6–31651.1)	37.2 (31.5–45.1)	67860.3 (57312.3–82137.7)	38.7 (33–46.4)	0.3 (0.21–0.39)
	Philippines	2261.4 (1868.2–2774)	4.9 (4.1–6)	4564.8 (3781.3–5581.7)	4.3 (3.6–5.2)	−0.46 (−0.5 to −0.42)
	Qatar	142.6 (116.2–181.2)	35 (29.1–43.3)	1521.2 (1249.1–1875.1)	42.9 (36–52)	0.84 (0.72–0.96)
	Saudi Arabia	2629.9 (2163.2–3256.9)	23.2 (19.3–28.2)	12230.1 (10076.5–15070.3)	28.9 (24.4–35)	0.99 (0.84–1.14)
	Singapore	256.8 (215.5–313)	7.9 (6.6–9.5)	681.6 (571.5–819.3)	8.9 (7.4–10.6)	0.27 (0.16–0.37)
	Sri Lanka	1199.7 (990.3–1452)	7.8 (6.4–9.4)	2125.4 (1792–2578.9)	8.5 (7.2–10.3)	0.69 (0.42–0.96)
	Syrian Arab Republic	2084.3 (1732.7–2558.2)	26.3 (22–32.1)	5021.5 (4167–6115.9)	34.3 (28.6–41.6)	1.15 (0.89–1.41)
	Tajikistan	1428.3 (1189.1–1720.5)	41.2 (34.7–50.2)	3529.5 (2947.2–4244.1)	41.5 (34.7–49.8)	0.14 (0.07–0.21)
	Thailand	2688.9 (2253.9–3217.4)	5.1 (4.3–6.1)	4950.2 (4153.8–5955)	5.7 (4.8–6.9)	0.42 (0.38–0.45)
	Timor-Leste	27.6 (22.4–34.3)	4.7 (3.9–5.8)	58.8 (49.5–71)	5.2 (4.3–6.3)	0.41 (0.37–0.45)
	Turkmenistan	1053.8 (871.3–1270.8)	41.5 (34.5–49.8)	2137.4 (1778.3–2585.8)	42.8 (35.9–51.5)	0.14 (0.09–0.19)
	Türkiye	13046.5 (10787.4–15924.4)	27.8 (23.2–34)	37359.1 (31518.5–44775.5)	38.9 (32.7–46.5)	1.45 (1–1.9)
	United Arab Emirates	564.1 (459.8–709.1)	34.6 (29.1–42.1)	5629.6 (4522–6968.8)	39.5 (32.9–47.4)	0.61 (0.45–0.77)
	Uzbekistan	6241.6 (5192.6–7547.4)	43.9 (36.8–52.9)	14168.2 (11910.6–17312.5)	41.7 (35.3–50.7)	0 (−0.09 to 0.08)
	Viet Nam	3050.9 (2533.9–3661.8)	5.8 (4.8–6.9)	6801.3 (5612.2–8273.1)	6.1 (5.1–7.4)	0.34 (0.29–0.39)
	Yemen	1690.8 (1376.9–2032.3)	21.4 (17.5–25.8)	6700.5 (5499.8–8342.7)	27.5 (22.9–34.1)	1.07 (0.9–1.23)
Incidence
	Afghanistan	164.5 (137.4–197.5)	2.2 (1.8–2.7)	589.5 (491.6–729.5)	2.6 (2.3–3.3)	0.55 (0.47–0.62)
	Armenia	130.6 (111.2–157.9)	4.1 (3.5–4.9)	175.5 (150.3–209.7)	4.8 (4.1–5.7)	0.7 (0.66–0.75)
	Azerbaijan	297.6 (255.4–361.3)	4.7 (4.1–5.7)	590.1 (504.3–727.1)	4.9 (4.2–6)	0.13 (0.07–0.2)
	Bahrain	9.9 (8.3–12)	1.9 (1.7–2.3)	41.9 (35.4–51.4)	2.3 (2–2.8)	0.98 (0.82–1.14)
	Bangladesh	3567.4 (3044.9–4351.5)	4.9 (4.2–5.9)	9014.7 (7758.6–11055.1)	5.6 (4.8–6.8)	0.2 (0.12–0.29)
	Bhutan	19.7 (16.4–24.1)	4.6 (3.9–5.6)	45.3 (38.2–54.9)	5.9 (5–7.1)	0.83 (0.76–0.91)
	Cambodia	40.9 (34.3–50.6)	0.5 (0.4–0.6)	109.2 (91.8–135)	0.7 (0.6–0.8)	0.79 (0.76–0.81)
	China	8315.7 (7018–10181.6)	0.7 (0.6–0.9)	24941.1 (21583.3–29820.9)	1.4 (1.2–1.7)	2.93 (2.41–3.46)
	Cyprus	59.7 (51–72.3)	7.3 (6.2–8.8)	130.6 (111.1–157.7)	8.1 (6.9–9.7)	0.09 (−0.13 to 0.31)
	Democratic People's Republic of Korea	167.4 (140.5–204.2)	0.8 (0.7–1)	305.2 (260.4–373.6)	1 (0.8–1.2)	0.49 (0.45–0.54)
	Georgia	282.8 (243.6–341.9)	4.7 (4.1–5.8)	214.8 (185.3–256.4)	4.9 (4.2–5.8)	0.12 (0.09–0.16)
	India	32368.4 (27779.1–39341.7)	5 (4.3–6)	84478.5 (72939.8–102208)	6 (5.2–7.3)	0.72 (0.63–0.81)
	Indonesia	1025 (867.7–1263.4)	0.7 (0.6–0.8)	2195.1 (1852.2–2712.2)	0.7 (0.6–0.9)	0.19 (0.13–0.26)
	Iran (Islamic Republic of)	1229.9 (1019.1–1526.5)	3.1 (2.6–3.9)	2701.9 (2280.6–3377.8)	2.8 (2.4–3.5)	0.23 (−0.02 to 0.48)
	Iraq	253.8 (216.5–299.3)	1.8 (1.6–2.2)	1059.7 (889.6–1313.8)	2.8 (2.3–3.4)	1.18 (1.11–1.24)
	Israel	509.6 (442.7–607.5)	10.7 (9.3–12.8)	1270.5 (1085.9–1523.4)	13 (11.1–15.8)	−0.02 (−0.5 to 0.46)
	Jordan	77.6 (65.9–90.4)	2.8 (2.4–3.2)	379.4 (318–465.4)	3.2 (2.7–3.9)	0.87 (0.72–1.02)
	Kazakhstan	651.5 (555–788.2)	4.3 (3.7–5.2)	1067.1 (907.4–1317.2)	5.4 (4.6–6.6)	0.62 (0.46–0.77)
	Kuwait	53.2 (47–60)	3.1 (2.8–3.5)	179.1 (149–229.6)	3.2 (2.7–3.9)	−0.26 (−0.65 to 0.13)
	Kyrgyzstan	155.3 (133.6–189.5)	4.3 (3.7–5.3)	285 (241.8–350)	4.5 (3.8–5.5)	0.14 (0.11–0.17)
	Lao People's Democratic Republic	17 (14.2–21.1)	0.5 (0.4–0.6)	46 (38.3–57.1)	0.6 (0.5–0.8)	0.72 (0.69–0.75)
	Lebanon	159.1 (134–195)	5.9 (5–7.3)	460 (389.2–563.2)	7.5 (6.4–9.1)	0.88 (0.77–0.98)
	Malaysia	90.9 (77.2–110)	0.6 (0.5–0.7)	271.5 (230–326.3)	0.8 (0.7–1)	1.56 (1.31–1.82)
	Maldives	0.8 (0.7–1)	0.5 (0.4–0.6)	3.7 (3–4.7)	0.6 (0.5–0.8)	1.05 (0.92–1.17)
	Myanmar	192.9 (162.6–235.7)	0.5 (0.5–0.7)	403.1 (339.8–495.3)	0.7 (0.6–0.9)	0.85 (0.8–0.9)
	Nepal	645.2 (547.9–783.2)	4.6 (4–5.5)	1644 (1366.4–2016.7)	5.7 (4.8–7)	0.74 (0.64–0.84)
	Oman	32.5 (26.7–40.3)	2 (1.7–2.4)	154.9 (127.7–196.8)	3 (2.6–3.7)	1.26 (1.17–1.36)
	Pakistan	3630.4 (3126.8–4383.6)	4.9 (4.3–5.9)	11033 (9356.9–13491.9)	6 (5.2–7.3)	0.62 (0.55–0.7)
	Philippines	223.9 (187.4–277.6)	0.4 (0.4–0.5)	569.3 (480.1–706.1)	0.5 (0.4–0.6)	0.46 (0.42–0.51)
	Qatar	12.3 (9.9–16.1)	2.7 (2.3–3.3)	126.5 (101.8–162)	3.4 (2.9–4.2)	0.79 (0.77–0.8)
	Saudi Arabia	307.4 (255.3–381.3)	2.5 (2.1–3)	926.6 (759.7–1162.1)	2.1 (1.8–2.5)	−0.94 (−1.1 to −0.78)
	Singapore	17.3 (14.5–21.4)	0.5 (0.4–0.6)	45.4 (38.5–54.8)	0.6 (0.5–0.8)	0.81 (0.61–1.02)
	Sri Lanka	114.9 (95.6–141.7)	0.7 (0.6–0.9)	229 (196.4–276.9)	0.9 (0.8–1.1)	1.19 (0.9–1.47)
	Syrian Arab Republic	214 (180.1–261.3)	2.4 (2.1–3)	446.1 (380.5-543.1)	3.1 (2.7–3.8)	0.81 (0.58–1.04)
	Tajikistan	163 (140.3–198.3)	4.4 (3.8–5.4)	399.4 (334.9–492.3)	4.6 (3.9–5.6)	0.13 (0.04–0.23)
	Thailand	269.9 (224.6–334.3)	0.5 (0.4–0.6)	490.1 (417.9–594.9)	0.6 (0.5–0.8)	0.61 (0.54–0.68)
	Timor-Leste	3.1 (2.6–3.9)	0.5 (0.4–0.6)	7.5 (6.4–9.2)	0.6 (0.5–0.8)	0.93 (0.85–1.01)
	Turkmenistan	134 (113.6–162.5)	5 (4.3–6.1)	282.9 (239.4–347)	5.6 (4.8–6.8)	0.48 (0.4–0.55)
	Türkiye	1333.6 (1130.7–1642)	2.7 (2.3–3.3)	2800.1 (2390.6–3335.8)	3 (2.6–3.6)	0.23 (0.03–0.42)
	United Arab Emirates	51.4 (41.7–66.5)	2.8 (2.4–3.5)	523.2 (422.5–664.2)	3.9 (3.3–4.7)	1.02 (0.86–1.18)
	Uzbekistan	642.8 (548.5–781.1)	4.2 (3.6–5.1)	1833.5 (1570.4–2242.1)	5.4 (4.7–6.5)	0.73 (0.68–0.78)
	Viet Nam	278.9 (234.2–343.1)	0.5 (0.4–0.6)	692.2 (577.5–849.2)	0.6 (0.5–0.8)	0.85 (0.78–0.91)
	Yemen	191.7 (159.9–232.5)	2.1 (1.8–2.6)	746.5 (618.7–930.1)	2.8 (2.3–3.4)	0.85 (0.82–0.88)
Deaths
	Afghanistan	16.9 (6.3–50.6)	0.3 (0.1–0.8)	32.5 (12–82.5)	0.3 (0.1–0.7)	0.63 (0.47–0.8)
	Armenia	9.8 (8.2–11.3)	0.3 (0.3–0.4)	13.7 (11–16.4)	0.3 (0.3–0.4)	0.08 (−0.31 to 0.48)
	Azerbaijan	9.9 (7–13.9)	0.2 (0.1–0.2)	13.2 (7.9–21.9)	0.1 (0.1–0.2)	−0.76 (−0.88 to −0.63)
	Bahrain	0.3 (0.1–0.7)	0.2 (0.1–0.5)	1 (0.6–2.1)	0.2 (0.1–0.3)	−0.73 (−0.96 to −0.49)
	Bangladesh	301.4 (203.9–392.8)	0.6 (0.4–0.8)	537.3 (337.2–784.4)	0.4 (0.3–0.6)	−1.46 (−1.6 to −1.31)
	Bhutan	1.3 (0.7–2.1)	0.5 (0.3–0.8)	2.8 (1.7–4.7)	0.5 (0.3–0.8)	−0.38 (−0.43 to −0.32)
	Cambodia	22.6 (12.5–34.5)	0.5 (0.3–0.8)	42.3 (24.7–61.4)	0.4 (0.2–0.6)	−1.11 (−1.18 to −1.04)
	China	4411.5 (2972.2–5559.9)	0.7 (0.5–0.9)	5640.3 (4394.6–7497.2)	0.3 (0.3–0.4)	−3.05 (−3.42 to −2.67)
	Cyprus	14.4 (9.6–20.9)	3.2 (1.9–4.9)	21.1 (16–27.4)	1.3 (0.9–1.7)	−2.89 (−3.23 to −2.55)
	Democratic People's Republic of Korea	69.9 (43.1–105.2)	0.6 (0.4–0.9)	126.1 (83.3–195)	0.5 (0.3–0.7)	−0.8 (−0.87 to −0.73)
	Georgia	18.4 (13.5–25.3)	0.3 (0.2–0.4)	17.1 (13–22.1)	0.3 (0.2–0.4)	−0.91 (−2.06 to 0.26)
	India	2149.1 (1542–2906.7)	0.5 (0.3–0.6)	3628 (2449.6–5064.1)	0.3 (0.2–0.5)	−1.22 (−1.35 to −1.08)
	Indonesia	441.6 (227.5–653.7)	0.5 (0.3–0.8)	670.3 (456.4–833.6)	0.4 (0.3–0.5)	−1.25 (−1.35 to −1.15)
	Iran (Islamic Republic of)	28.2 (18–36.6)	0.1 (0.1–0.2)	86 (38.8–115.9)	0.1 (0.1–0.2)	0.55 (0.16–0.95)
	Iraq	36.2 (26.7–48.4)	0.4 (0.3–0.5)	72.3 (51.9–100.2)	0.3 (0.2–0.4)	−0.64 (−0.68 to −0.6)
	Israel	15.4 (13.9–16.6)	0.3 (0.3–0.4)	52.9 (43.8–59.1)	0.4 (0.3–0.4)	0.78 (0.23–1.34)
	Jordan	4 (2.3–6.9)	0.3 (0.2–0.5)	16.1 (10.9–21.3)	0.2 (0.2–0.3)	−0.06 (−0.31 to 0.19)
	Kazakhstan	73.3 (64.2–81.9)	0.5 (0.5–0.6)	87.1 (66.9–114)	0.5 (0.4–0.6)	−1.03 (−1.39 to −0.65)
	Kuwait	1.8 (1.6–2.1)	0.2 (0.2–0.3)	4.4 (3.7–5.2)	0.2 (0.1–0.2)	−0.87 (−2.86 to 1.16)
	Kyrgyzstan	21.7 (17.2–27.5)	0.6 (0.5–0.8)	10.9 (8.5–13.5)	0.2 (0.2–0.3)	−5.12 (−6.2 to −4.03)
	Lao People's Democratic Republic	5.4 (2.7–8)	0.3 (0.1–0.5)	8.6 (4.5–13.6)	0.2 (0.1–0.3)	−1.25 (−1.34 to −1.16)
	Lebanon	10.6 (5.8–16.7)	0.5 (0.3–0.8)	27.7 (21.3–35.8)	0.4 (0.3–0.5)	−0.42 (−0.53 to −0.31)
	Malaysia	7.7 (5.6–9.7)	0.1 (0.1–0.1)	17.7 (14.2–23.1)	0.1 (0.1–0.1)	−1.26 (−1.67 to −0.84)
	Maldives	0.2 (0.1–0.3)	0.2 (0.2–0.3)	0.5 (0.3–0.6)	0.2 (0.1–0.2)	−1.53 (−1.66 to −1.39)
	Myanmar	70.8 (37.8–107.6)	0.3 (0.1–0.4)	85.8 (55.6–127.6)	0.2 (0.1–0.3)	−1.81 (−1.96 to −1.67)
	Nepal	49.3 (28.4–72.6)	0.5 (0.3–0.8)	83.8 (54.6–122.7)	0.4 (0.3–0.6)	−1.08 (−1.21 to −0.95)
	Oman	1 (0.5–2.6)	0.1 (0.1–0.3)	2.3 (1.4–4.3)	0.1 (0.1–0.2)	0.34 (0.05–0.63)
	Pakistan	243.6 (108.6–413.2)	0.5 (0.2–0.8)	465.7 (282.9–667)	0.4 (0.2–0.6)	−0.76 (−0.89 to −0.63)
	Philippines	77.7 (42.4–107.2)	0.3 (0.1–0.4)	139.4 (112–173.7)	0.2 (0.1–0.2)	−1.59 (−1.87 to −1.32)
	Qatar	0.8 (0.5–1.1)	0.9 (0.6–1.3)	3.4 (2.4–4.8)	0.4 (0.3–0.6)	−2.57 (−3.02 to −2.13)
	Saudi Arabia	8.2 (4.6–13.7)	0.1 (0.1–0.2)	19.4 (12.2–30.3)	0.1 (0.1–0.1)	−0.6 (−1.03 to −0.18)
	Singapore	2.7 (2.5–2.8)	0.1 (0.1–0.1)	2.1 (1.8–2.3)	0 (0–0)	−5.57 (−5.86 to −5.27)
	Sri Lanka	6.4 (4.5–8.2)	0.1 (0–0.1)	6.8 (4.5–10.2)	0 (0–0)	−3.14 (−3.37 to −2.91)
	Syrian Arab Republic	21.1 (14.8–29.1)	0.4 (0.3–0.5)	33.7 (22.8–48.1)	0.3 (0.2–0.4)	−0.59 (−0.73 to −0.45)
	Tajikistan	16.3 (10.3–24.3)	0.4 (0.3–0.5)	23.8 (13.1–41.7)	0.3 (0.2–0.5)	−0.78 (−0.87 to −0.68)
	Thailand	29.2 (22.6–42.4)	0.1 (0.1–0.1)	108.6 (72.5–148)	0.1 (0.1–0.1)	0.6 (0.34–0.87)
	Timor-Leste	0.9 (0.4–1.6)	0.3 (0.1–0.6)	2.1 (1.1–4.2)	0.3 (0.1–0.5)	−0.62 (−0.77 to −0.47)
	Turkmenistan	9.5 (7.3–11.5)	0.4 (0.3–0.4)	14.9 (10–22.4)	0.3 (0.2–0.5)	−0.69 (−0.89 to −0.5)
	Türkiye	187 (129.2–261.2)	0.5 (0.4–0.7)	355.7 (262.8–456.6)	0.4 (0.3–0.5)	−0.71 (−0.85 to −0.57)
	United Arab Emirates	1.3 (0.8–2)	0.2 (0.1–0.3)	5.3 (3.6–7.9)	0.2 (0.1–0.3)	1.25 (0.75–1.76)
	Uzbekistan	32.5 (26.5–39.8)	0.2 (0.2–0.2)	69.1 (53.3–86.1)	0.2 (0.2–0.3)	0.58 (0.05–1.11)
	Viet Nam	104.7 (46.3–167.7)	0.3 (0.1–0.5)	145.6 (90.2–198.4)	0.2 (0.1–0.2)	−1.74 (−1.86 to −1.61)
	Yemen	6.5 (3–14.9)	0.1 (0.1–0.3)	24.7 (13.5–47.2)	0.2 (0.1–0.3)	1.16 (0.99–1.33)
Disability-adjusted life years
	Afghanistan	785 (372.5–2108.8)	10.7 (5.4–27.7)	2047.6 (1075.8–4398.3)	11.5 (6.4–23.5)	0.53 (0.37–0.69)
	Armenia	637.1 (532.3–746.2)	19.8 (16.5–23.1)	649.5 (518.2–780.5)	17.4 (14–20.9)	−0.33 (−0.56 to −0.09)
	Azerbaijan	877.1 (648.7–1133.6)	13.8 (10.2–17.8)	1468.9 (1074.2–2023.3)	12.7 (9.3–17.4)	−0.17 (−0.28 to −0.05)
	Bahrain	31.7 (20.6–49.1)	8.8 (5.5–15)	126.9 (86.3–177.7)	8.4 (5.9–12.3)	−0.06 (−0.14 to 0.01)
	Bangladesh	14861.8 (10874.9–18797.9)	23 (17–27.9)	28124.9 (20617.2–36319.8)	18.4 (13.5–24.1)	−0.71 (−0.74 to −0.68)
	Bhutan	74.9 (49.7–103.5)	20.2 (13.3–28.3)	132.6 (93.5–188.1)	18.7 (13.3–26.4)	−0.29 (−0.33 to −0.24)
	Cambodia	878.7 (520.3–1359.8)	13.7 (8–20.6)	1430.6 (861.8–2061.2)	10.3 (6.3–14.6)	−1.07 (−1.15 to −0.99)
	China	162185.8 (115399.6–206768.3)	18.4 (12.7–23.1)	136932.5 (109829.8–171866)	7.7 (6.2–9.6)	−2.93 (−3.23 to −2.64)
	Cyprus	380.4 (285.8–498.1)	59.7 (42.9–82.4)	642.5 (508.8–808.3)	36.6 (28.9–46.1)	−1.6 (−1.81 to −1.39)
	Democratic People's Republic of Korea	2260.1 (1369.1–3500.5)	13.9 (8.9–20.3)	3099 (2084.1–4769.2)	10.8 (7.3–16.2)	−0.74 (−0.81 to −0.68)
	Georgia	1152.3 (858.8–1471.2)	19.6 (14.6–25.1)	820.5 (631.4–1020.2)	17.3 (13.2–21.5)	−0.96 (−1.53 to −0.38)
	India	116577.3 (92281.7–150915.8)	19.3 (15.3–24.3)	209490.1 (160959.8–266164.7)	15.8 (12.1–20.2)	−0.65 (−0.74 to −0.57)
	Indonesia	15218 (8932.1–20249.5)	12.9 (7.1–18.3)	20530.5 (14593.9–25014.5)	8.9 (6.3–10.8)	−1.43 (−1.53 to −1.33)
	Iran (Islamic Republic of)	2962.6 (2239.1–3817.7)	8.1 (6–10.6)	7153.1 (5158.9–9696.6)	8 (5.7–10.6)	0.48 (0.28–0.68)
	Iraq	1984.6 (1502.7–2530.1)	14.6 (11.6–18.6)	4383.6 (3317.4–5692.7)	12.8 (9.9–16.3)	−0.37 (−0.45 to −0.3)
	Israel	1188.4 (889.2–1542.8)	25.5 (19–33.1)	2847.6 (2184.3–3713.1)	26.9 (20.2–35.8)	−0.22 (−0.7 to 0.26)
	Jordan	301.8 (212.5–429.6)	13.4 (9.5–19)	1302.4 (984.1–1701)	12.6 (9.7–16.3)	0.17 (0.02–0.33)
	Kazakhstan	4032 (3498.1–4634.3)	26.9 (23.4–30.9)	4714.3 (3838.2–5920.8)	24.1 (19.7–30.2)	−0.84 (−1.13 to −0.55)
	Kuwait	186.6 (148.4–232.7)	13.8 (11.4–16.8)	499.8 (365.9–666)	10 (7.6–12.7)	−1 (−1.93 to −0.07)
	Kyrgyzstan	1272.8 (1023–1558.1)	31.7 (25.7–38.2)	892.7 (705–1137.7)	14.3 (11.3–18.3)	−3.57 (−4.28 to −2.86)
	Lao People's Democratic Republic	211.1 (126.7–301)	7.9 (4.4–11.2)	336.3 (206.6–497.4)	5.9 (3.5–8.7)	−1.04 (−1.11 to −0.98)
	Lebanon	645.5 (440.5–889.3)	26 (17.8–35.7)	1476.5 (1135.1–1863.1)	24.2 (18.7–30.6)	−0.04 (−0.12 to 0.04)
	Malaysia	400.6 (318.8–482)	3.2 (2.5–3.8)	929.2 (741.9–1163.3)	3 (2.4–3.7)	−0.34 (−0.6 to −0.08)
	Maldives	8.1 (5.2–13.7)	6.3 (4.5–8.9)	19.6 (14.5–25.7)	4.4 (3.3–5.6)	−1.28 (−1.39 to −1.17)
	Myanmar	3132.7 (1836.4–4768.5)	9.7 (5.6–14.1)	3552.9 (2409.6–5198.1)	6.6 (4.5–9.5)	−1.55 (−1.68 to −1.42)
	Nepal	2722 (1877.8–3633.7)	21.1 (14.3–28.5)	4541.9 (3406.6–5970.2)	17 (12.7–22.3)	−0.78 (−0.87 to −0.69)
	Oman	103.7 (66.7–169.8)	7.9 (5.2–13.3)	368.7 (250.6–510)	8.5 (5.9–12)	0.7 (0.52–0.88)
	Pakistan	12042.7 (7440.6–17724.3)	17.4 (10.6–25.7)	27074 (20198.1–36271.7)	16.3 (12–21.6)	−0.45 (−0.54 to −0.37)
	Philippines	3336.5 (2218.5–4086.7)	7.7 (4.6–10.1)	5127.8 (4278.4–6256.2)	5.4 (4.5–6.6)	−1.47 (−1.72 to −1.23)
	Qatar	53.8 (39.1–72.2)	22.5 (17.6–29.5)	365.8 (267.1–492.1)	15 (11.4–19.6)	−1.19 (−1.38 to −1)
	Saudi Arabia	760 (544.9–1043.9)	7 (4.9–9.7)	2743.6 (1957.9–3831.1)	7.1 (5.3–9.8)	0.28 (0.07–0.49)
	Singapore	120.4 (104.6–140.9)	4.3 (3.8–5)	151.5 (112.3–201.1)	2 (1.5–2.6)	−2.67 (−2.86 to −2.48)
	Sri Lanka	399.4 (312.3–503.9)	2.9 (2.2–3.6)	511 (372.7–682.7)	2.1 (1.5–2.7)	−1.04 (−1.14 to −0.94)
	Syrian Arab Republic	1184.2 (827.8–1615.3)	13.9 (10.7–18)	1771.2 (1270.4–2315.7)	13.1 (9.5–17)	−0.15 (−0.18 to −0.13)
	Tajikistan	1161.9 (717.2–1721.6)	23.1 (16.6–31.5)	1772.3 (1127.4–2727)	19 (12.5–28.8)	−0.44 (−0.57 to −0.3)
	Thailand	1410 (1125.1–1842.9)	3.1 (2.4–4.1)	3277.7 (2421.3–4238.9)	3.6 (2.7–4.6)	0.43 (0.25–0.61)
	Timor-Leste	38.8 (23–62.7)	8.4 (4.2–15.6)	74.2 (43–134.8)	7.3 (4.1–13.3)	−0.63 (−0.82 to −0.44)
	Turkmenistan	638.6 (494.1–757.3)	20.9 (16.9–24.7)	963.9 (708.5–1298.5)	19.3 (14.2–25.9)	−0.45 (−0.56 to −0.34)
	Türkiye	8750.8 (6029.7–11849.9)	19.3 (13.9–25.6)	14462.7 (11588.5–17776.8)	15.8 (12.6–19.3)	−0.57 (−0.68 to −0.46)
	United Arab Emirates	148.6 (103.6–200.3)	11 (8.1–14.8)	1088.6 (761.1–1554.5)	10 (7.6–13.3)	0.29 (0.09–0.49)
	Uzbekistan	2792.7 (2226.4–3420.9)	15.6 (12.7–19.4)	5219.9 (4153.1–6377.9)	15.6 (12.4–19)	0.04 (−0.26 to 0.35)
	Viet Nam	3342.7 (1850.4–4954)	7 (3.8–10.6)	4651.8 (3199.6–6133.5)	4.8 (3.2–6.2)	−1.39 (−1.49 to −1.29)
	Yemen	530.5 (321.6–966.7)	6.9 (4.3–11.1)	1965.1 (1320.2–2821.2)	8.8 (6–12.8)	1.06 (0.88–1.24)

3.7.1. Prevalence

High-burden settings. Cyprus (113.6; +0.67 %), Israel (136.5; −0.53 %), and Lebanon (99.1; +0.71 %) continue to exhibit the greatest prevalence, reflecting longstanding epidemiological saturation rather than recent acceleration. Among upper- and lower-middle-income settings, Turkey (38.9; +1.45 %) and Yemen (27.5; +1.07 %) recorded the fastest proportional increases (Table 2, Fig. 2A).

Fig. 2.

Age-standardized rates (per 100 000) of inflammatory bowel disease across Asian countries, 2021. Choropleth panels display ASPR (prevalence), ASIR (incidence), ASMR (mortality), and ASDR (DALYs); darker shades indicate higher burden. ASR, age-standardized rate; ASPR, age-standardized prevalence rate; ASIR, age-standardized incidence rate; ASMR, age-standardized mortality rate; ASDR, age-standardized DALY rate. The maps show marked geographic heterogeneity, with distinct high- and low-burden clusters across subregions.

Rapidly emerging burden. China experienced the largest absolute rise—its age-standardised prevalence rate (ASPR) nearly doubled from 5.6 to 9.2 (EAPC +2.54 %), translating to more than 100 000 additional prevalent cases. Similar but smaller surges were observed in Oman (+1.18 %), Iraq (+1.11 %), and Malaysia (+1.31 %) (Table 2, Fig. 2A, Supplementary Fig. 1A).

Stable or plateauing burden. Central-Asian republics (Kazakhstan, Tajikistan, Turkmenistan, Uzbekistan) and Kyrgyzstan showed near-zero annual change (+0.09 % to +0.14 %), suggesting epidemiological equilibrium. Modest declines were confined to the Philippines (−0.46 %) and Kuwait (−0.39 %), whereas the Democratic People's Republic of Korea remained essentially static (−0.07 %) (Table 2, Fig. 2A, Supplementary Fig. 1A).

3.7.2. Incidence

Accelerating incidence. China again led the region (ASIR 1.4; +2.93 %), followed by Bahrain (2.3; +0.98 %), Oman (3.0; +1.26 %), Malaysia (0.8; +1.56 %), Iraq (2.8; +1.18 %), and Yemen (2.8; +0.85 %). These trends suggest genuine growth in disease onset rather than diagnostic artefact alone.

Persistently high incidence. Israel (13.0; ≈0 %) and Cyprus (8.1; +0.09 %) remain clear outliers, maintaining very high baseline incidence without material acceleration—indicative of mature endemicity.

Declining or stabilising incidence. Saudi Arabia (2.1; −0.94 %), Kuwait (3.2; −0.26 %), and the Philippines (0.5; +0.46 %) displayed flat or negative trends, implying either attenuation of risk-factor transmission or saturation of susceptible cohorts(Table 2, Fig. 2B, Supplementary Fig. 1B).

3.7.3. Mortality

Continental decline. Thirty-eight of the 43 settings achieved statistically significant reductions in IBD-related mortality. The steepest falls were registered in Singapore (ASDR ≈ 0; −5.57 %), Kyrgyzstan (0.2; −5.12 %), China (0.3; −3.05 %), and Cyprus (1.3; −2.89 %), reflecting improved access to biologics, specialised care, and timely surgical rescue.

Residual mortality hotspots. Afghanistan (0.3; +0.63 %), Iran (0.1; +0.55 %), and Israel (0.4; +0.78 %) experienced small but significant upward drifts, likely attributable to conflict-related health-system disruption (Afghanistan), an expanding prevalent pool (Iran), and ageing IBD cohorts (Israel) (Table 2, Fig. 2C, Supplementary Fig. 1C).

3.7.4. Disability-adjusted life years

Substantial gains in East and South-East Asia. China more than halved its DALY rate—from 18.4 to 7.7 (EAPC −2.93 %)—while Cambodia, Indonesia, Myanmar, Viet Nam, and Thailand each recorded annual declines of ≥1 %. These improvements counterbalanced rising prevalence by shortening survival-adjusted morbidity and preventing premature deaths.

Largest residual DALY loads. Cyprus (36.6; −1.60 %), Kazakhstan (24.1; −0.84 %), Lebanon (24.2; −0.04 %), and Israel (26.9; −0.22 %) maintained the highest burden, mirroring their prevalence profiles.

Areas of concern. Afghanistan (+0.53 %), Oman (+0.70 %), Iran (+0.48 %), and Saudi Arabia (+0.28 %) showed rising or stagnant DALY rates, underscoring service-delivery gaps and the need for targeted resource allocation (Table 2, Fig. 2D, Supplementary Fig. 1D).

3.8. Practical implications

First, rapidly escalating incidence and prevalence in China, Türkiye, Oman, Iraq, Malaysia and several Gulf states underscore an urgent need to expand gastroenterology training, diagnostic endoscopy, and affordable access to advanced therapeutics; second, long-standing high-prevalence plateaus in Cyprus, Israel and Lebanon highlight the growing demand for lifelong disease-management infrastructure, including colorectal-cancer surveillance and multidisciplinary care of extra-intestinal manifestations; third, although most countries achieved appreciable declines in IBD-related mortality, persisting deaths in conflict-affected or highly resource-constrained settings (e.g., Afghanistan, Yemen) point to fragile supply chains for immunosuppressants and surgical services; and fourth, the steep reductions in DALY rates observed in East and South-East Asian settings illustrate the effectiveness of integrated chronic-care models, suggesting that wider adoption of similar approaches could accelerate morbidity attenuation in lagging nations.

3.9. Age-specific inflammatory bowel disease burden in Asia, 2021

In 2021 the age-specific incidence of IBD in Asia displayed a classic inverted-U trajectory. During early childhood (<10 years) IBD was extremely uncommon, with rates hovering around 0.02 per 100 000 in both boys and girls. Incidence rose steeply through adolescence, reaching approximately 1 per 100 000 by 15–19 years. This acceleration continued into early adulthood, peaking at roughly 4.3 per 100 000 in men and 4.2 per 100 000 in women at 30–34 years. From the mid-30s to late-50s incidence stabilised at its highest level—about 6–7 per 100 000—before beginning a gradual decline after 60 years. By the oldest age stratum (≥95 years) incidence had fallen to ∼3 per 100 000 in men and ∼2.5 per 100 000 in women (Fig. 3A).

Fig. 3.

Age-specific burden of inflammatory bowel disease in Asia, 2021. Panels show (A) prevalence, (B) incidence, (C) disability-adjusted life years (DALYs), and (D) mortality, expressed as age-specific rates per 100 000 population. Curves are stratified by sex.

Across the entire life-course, male-to-female differences were modest, with sex-specific curves largely overlapping. Hence, the Asian pattern is characterised by minimal sex disparity, a rapid post-pubertal rise, a broad mid-life plateau, and attenuation in later life—features typical of regions where the IBD epidemic has transitioned from emergence to maturation (Fig. 3A).

In 2021 the age-specific point prevalence of IBD in Asia rose exponentially from childhood to mid-adulthood and then stabilised at a high plateau before tapering in advanced age. In early childhood (<10 years) IBD remained rare, at roughly 0.02 per 100 000 in both sexes. Prevalence increased ten-fold during late childhood (5–9 years: ≈0.39 per 100 000) and accelerated further through adolescence, reaching about 5 per 100 000 at 15–19 years (Fig. 3B).

The steep ascent continued into young adulthood: prevalence doubled to ≈11 per 100 000 by 20–24 years and almost doubled again (≈21 per 100 000) by 25–29 years. Peak values were recorded between 40 and 64 years, where male rates hovered between 49 and 60 per 100 000 and female rates between 52 and 64 per 100 000, indicating a broad mid-life plateau rather than a single apex. Thereafter a gentle decline emerged: by 75–79 years prevalence had fallen to about 52 per 100 000 in men and 50 per 100 000 in women, with a further decrement to the mid-40 s per 100 000 in the nonagenarian cohort.

Across the life-course, sex differentials were modest and phase-specific. Females exhibited slightly higher prevalence from adolescence to the mid-40 s, but male curves converged thereafter, yielding near-parity in later decades. Collectively, these patterns depict an Asian IBD burden that accumulates rapidly during the reproductive years, saturates through middle age, and attenuates only gradually in the elderly, with minimal sustained sex divergence (Fig. 3B).

Across Asia in 2021, age-specific DALY rates for IBD describe a pronounced J-shaped trajectory. During early childhood (<5 years) the burden is modest (≈2 DALYs per 100 000 for both sexes) and falls by roughly half in late childhood, but from adolescence onwards rates rise rapidly: they triple between 15–19 years and 25–29 years, reaching about 7 (males) to 8 (females) DALYs per 100 000. Through the primary working ages (30–54 years) the increase slows, stabilising in the low-to mid-teens, with only small sex differences. From the mid-fifties, however, a steep, age-proportional escalation resumes. By 70–74 years the burden has more than doubled again (≈38 DALYs per 100 000 in males and 31 in females) and continues to climb sharply in the oldest groups, peaking at roughly 150 (males) and 100 (females) among nonagenarians. In the ≥95-year cohort the pattern reverses: women, who survive longer with disability, exhibit higher rates (≈144 vs 126). These data highlight that disability increasingly dominates the IBD burden after mid-life, with men experiencing greater loss of healthy life-years until the very oldest ages, when female longevity tips the balance (Fig. 3C).

In Asia, mortality attributable to IBD in 2021 remained negligible throughout childhood—well below 0.03 deaths per 100 000 in both sexes under 15 years of age. Beginning in late adolescence, however, the death rate rose steadily and, from about age 30 onward, increased almost log-linearly with advancing age. Among adults aged 25–29 years the rate was still modest (≈0.06–0.07 per 100 000), but it trebled by the early forties and exceeded 0.25 per 100 000 in men and 0.14 in women by 50–54 years. Thereafter an accelerating, age-proportional climb was evident: male rates quadrupled between 55 and 59 years (≈0.36) and 70–74 years (≈1.5), and more than doubled again by 80–84 years (≈4.7). Female mortality followed the same trajectory but at consistently lower levels (female-to-male ratio ∼0.7–0.8) until extreme old age. In the nonagenarian cohort (90–94 years) deaths reached 16.5 per 100 000 in men versus 10.7 in women; by ≥ 95 years, however, female mortality marginally surpassed that of males (≈17.0 vs 14.6 per 100 000), reflecting female longevity at ages where case-fatality is highest. Overall, these data show that IBD-related deaths are rare before mid-life but rise exponentially thereafter, with a persistent male excess that narrows—and ultimately reverses—only in the very oldest survivors (Fig. 3D).

3.10. Decomposition of change in IBD prevalence and DALYs, 1990–2021

Change components are absolute differences decomposed into contributions from population growth, population aging (age structure), and epidemiological change (age-specific rates). Percentages show each component's share of the overall difference; totals may exceed 100 % where opposing components offset each other (Supplementary Table 1).

3.11. Asia overall

Across Asia, prevalent IBD cases expanded by ∼0.80M. Population growth explained ∼56 % of the increase (0.45M), aging added ∼20 % (0.16M), and rising age-specific prevalence contributed the remaining ∼25 % (0.20M). In contrast, IBD DALYs increased modestly (∼0.21M) despite strong upward pressure from demographic change (aging 0.11M; 52 %; population growth 0.22M; 105 %); this was more than offset by substantial declines in age-specific DALY rates (−0.12M; −57 %), indicating improved survival and/or disability management relative to case growth (Fig. 4).

Fig. 4.

Decomposition of changes in inflammatory bowel disease burden in Asia and sub-regions, 1990–2021. Panels summarize Central Asia, East Asia, South Asia, Southeast Asia, and Asia overall. For each region, stacked bars partition the absolute change in disability-adjusted life years (DALYs) and prevalence into three additive components: population growth, population ageing (age structure), and epidemiologic change (age-specific rates). Positive segments indicate contributors to net increases; negative segments indicate offsets where improving age-specific outcomes reduced the overall change. Values are shown as absolute counts, with percentages denoting each component's share of the total.

4. Subregional patterns

4.1. South Asia

South Asia accounted for the largest absolute growth in IBD prevalence globally (+∼0.50M). Population expansion (0.35M; 71 %) was the principal driver, with smaller contributions from aging (0.06M; 11 %) and rising age-specific prevalence (0.09M; 18 %). Despite this large case growth, IBD DALYs increased by only ∼0.13M because strong demographic pressures—population growth (0.14M; 111 %) and aging (0.025M; 20 %)—were offset by meaningful reductions in age-specific DALY rates (−0.04M; −30 %). The mortality/disability gains were greater in males (−40 % epi component) than females (−22 %) (Fig. 4).

4.2. East Asia

East Asia showed moderate prevalence growth (+∼0.11M) but the highest proportional epidemiological contribution among Asian subregions: nearly half of the increase (0.52M; 48 %) stemmed from higher age-specific prevalence, exceeding the effects of population growth (0.33M; 31 %) and aging (0.02M; 21 %). In sharp contrast, DALYs declined on a rate basis: although aging (0.07M; 231 %) and population growth (0.04M; 132 %) exerted upward pressure, a very large negative epidemiological component (−0.79M; −263 %) yielded only a modest net increase (∼0.03M). The negative epi effect was particularly pronounced in females (−1134 %) reflecting dramatic declines in age-specific disability and/or mortality among women with IBD (Fig. 4).

4.3. Southeast Asia

Prevalence rose modestly (+∼0.02M), almost entirely due to demographic growth (population 80 %; aging 18 %); epidemiological change contributed only +3 %. DALYs, however, were strongly dampened by improved age-specific outcomes (−0.11M; −82 %), offsetting large demographic pressures (population +0.18M; 133 %; aging +0.007M; 49 %) and yielding a small positive overall change (∼0.014M) (Fig. 4).

4.4. Central Asia

Prevalence increased by ∼18.9K cases, attributable to population growth (76 %) and aging (25 %); age-specific prevalence declined slightly (−2 %). DALYs rose by ∼5.4K, but demographic effects (population +5.3K; aging +1.4K) were partly neutralized by reductions in age-specific DALY rates (−1.3K; −24 %). The epidemiological improvement was strongest in males (−37 %) relative to females (−13 %) (Fig. 4).

4.5. Future forecasts of Asia burden of inflammatory bowel disease

South Asia. Bayesian forecasts indicate that South Asia's age-standardised prevalence of IBD will flatten during the late 2020s and creep upward only marginally thereafter, rising from 46.2 per 100 000 in 2021 to about 48.1 by 2040 (Fig. 5A). Incidence, by contrast, is projected to continue its incremental climb, reaching roughly 6.6 per 100 000 (95 % UI 1.1–12.2) in 2040 and thereby consolidating the region's position as Asia's second-highest incidence zone (Fig. 5C). Because mortality already sits well below 0.4 deaths per 100 000 and is forecast to fall to 0.26, the principal burden will remain disability: DALY rates are expected to fall only modestly—from 16.1 to 13.2—leaving South Asia with the continent's second-largest pool of lost healthy life-years. Even these seemingly small percentage changes will translate into large absolute case-loads, underscoring the need for continued expansion of endoscopic capacity, biologic therapy, and population-based registries (Fig. 6AC)

Fig. 5.

Bayesian age–period–cohort (BAPC) forecasts of age-standardized inflammatory bowel disease rates to 2040. (A) South Asia and Southeast Asia: age-standardized prevalence rate (ASPR). (B) Central Asia and East Asia: ASPR. (C) South Asia and Southeast Asia: age-standardized incidence rate (ASIR). (D) Central Asia and East Asia: ASIR. Solid lines depict observed rates (1990–2021); dashed lines show posterior median projections (2022–2040). Shaded ribbons represent 95 % uncertainty intervals estimated via INLA. Rates are per 100 000 population (both sexes combined unless otherwise indicated).

Fig. 6.

Bayesian age–period–cohort (BAPC) forecasts to 2040 for inflammatory bowel disease burden. (A) South Asia and Southeast Asia: age-standardized DALY rate (per 100 000). (B) Central Asia and East Asia: age-standardized DALY rate (per 100 000). (C) South Asia and Southeast Asia: age-standardized death rate (ASDR; per 100 000). (D) Central Asia and East Asia: ASDR (per 100 000). Solid lines show observed rates (1990–2021); dashed lines indicate posterior median projections (2022–2040). Shaded ribbons denote 95 % uncertainty intervals (INLA). Rates are per 100 000 population (both sexes combined unless stated). A vertical marker at 2021 denotes the forecast start.

Southeast Asia. In stark contrast to South Asia, Southeast Asia appears poised for a prolonged epidemiological plateau. Prevalence is projected to edge down from 5.7 per 100 000 in 2021 to 5.4 by 2040, while incidence will remain an order of magnitude lower than any other Asian sub-region, staying below 0.8 per 100 000 (Fig. 5AC). DALY rates should decline further to roughly 5.6 per 100 000, and mortality is likely to remain essentially flat at about 0.22 deaths per 100 000. These forecasts suggest that the region will continue to shoulder the continent's lightest IBD burden, providing a rare window to consolidate services, improve registry coverage, and avert future surges (Fig. 6AC).

Central Asia. Central Asia will probably maintain one of the heaviest IBD burdens in Asia despite only modest year-on-year change. Prevalence, which dipped in the early 2000s, is projected to climb slowly from 45.6 to 47.7 per 100 000 by 2040, and incidence may reach 5.7 per 100 000 (Fig. 5BD). Disability remains the dominant concern: DALY rates, currently near 17.9 per 100 000, are forecast to decline only to 16.1, whereas mortality is projected to hover around 0.4 deaths per 100 000, albeit with very wide uncertainty intervals. The slow improvement, coupled with expanding predictive uncertainty, highlights the importance of sustained investment in chronic-care infrastructure and high-quality surveillance (Fig. 6BD).

East Asia. East Asia's IBD burden has already fallen markedly since the 1990s and is expected to stabilise at comparatively low levels, though long-range projections are highly uncertain. Prevalence is likely to hover around 10 per 100 000 through 2040, while median incidence projections suggest little net change; however, prediction intervals stretch from near zero to values that could triple current rates, reflecting sparse recent data (Fig. 5BD). DALY rates should fall further to about 6.8 per 100 000, and mortality is projected to remain low (≈0.38 deaths per 100 000) with wide uncertainty. Continued surveillance and maintenance of advanced therapeutic access will be essential to preserve these gains (Fig. 6BD).

5. Discussion

5.1. Core findings

This continent-wide analysis shows that Asia's IBD burden has expanded substantially since 1990, driven by concurrent rises in age-standardised prevalence and incidence, while age-standardised mortality and DALY rates declined. Demography was the dominant driver of the growth in cases (≈56 % population increase; ≈20 % ageing), but genuine epidemiologic change contributed a further quarter of the prevalence rise. Sub-regional heterogeneity is marked: South Asia continues to grow from a moderate baseline; Central Asia sustains one of the highest disability loads with only slow improvement; East Asia couples a rising or stable incidence with pronounced declines in disability; and Southeast Asia remains a low-burden plateau. Age-specific profiles are internally coherent—an inverted-U incidence curve, a mid-life prevalence plateau, and a J-shaped DALY curve—indicating accumulation of chronic disease in working ages and rapidly escalating disability in older adults. Forecasts to 2040 suggest continued prevalence creep in South and Central Asia, epidemiologic stabilization (but high uncertainty) in East Asia, and persistent low burden in Southeast Asia. Quantitative adjustment for diagnostic penetration would be preferable, but harmonized multi-country time series (endoscopy capacity, specialist density, utilization) were unavailable. We therefore interpret upward trends cautiously and offer a qualitative appraisal of diagnostic expansion. As comparable indicators (e.g., colonoscopy rates per capita, gastroenterologist density, insurance coverage) become available, we will integrate them into ecological models to disentangle true epidemiologic change from enhanced case detection.

5.2. Several observations were unexpected

First, East Asia combined one of the steepest proportional increases in incidence with the fastest DALY decline, implying that therapeutic gains and care integration can outpace epidemiologic expansion. Second, sex differentials were small across most metrics, but female DALY rates fell more than male rates in several sub-regions, suggesting benefit from earlier care engagement or differential treatment response. Third, Southeast Asia's projected stability contrasts with trajectories elsewhere, underscoring persistent inter-regional heterogeneity that is unlikely to be explained by diagnostics alone. Finally, at the oldest ages female mortality slightly exceeded male mortality, consistent with survival to high-risk ages rather than higher case fatality.

5.3. Comparison with existing literature

Our findings align with and extend prior reports that document a transition of IBD from Western concentration to global distribution and a maturing epidemic in parts of Asia [[22], [23], [24], [25], [26]]. Consistent with hospital-based series and registry reports, we observe rising incidence in China and parts of the Gulf, yet we show that disability has fallen fastest in East and Southeast Asia—likely reflecting earlier diagnosis, broader access to advanced therapies, and structured chronic care [27]. Unlike many single-country studies, our harmonized decomposition quantifies how population growth and ageing dominate case expansion, while improved age-specific outcomes offset much of the demographic pressure on DALYs. We also reconcile apparently discordant trends—rising prevalence with falling DALYs—by showing that survivorship and morbidity per case are improving even as more people live with IBD [28].

5.4. Drivers of regional heterogeneity

Three interacting forces likely underpin the divergent trajectories. (1) Environmental westernisation [29]. Rapid dietary change, antibiotic use, reduced helminth exposure and altered microbiota composition have been implicated in the surge of IBD in newly industrialised Asian megacities [[30], [31], [32]]. Regions entering later stages of urban transition—South Asia today, perhaps South-East Asia tomorrow—may therefore face delayed but inevitable incidence growth unless modifiable risk factors are addressed. (2) Diagnostic penetration. Expansion of colonoscopic services and insurance coverage can inflate measured incidence by unmasking latent disease. The steep early-2000s rise and subsequent plateau in East Asia is consistent with a “catch-up” in ascertainment followed by saturation. (3) Health-system resilience. Declining mortality and DALY rates reflect improved steroid stewardship, biologic and small-molecule availability, and multidisciplinary peri-operative care [33,34]. Yet countries affected by conflict (Afghanistan, Yemen, Syria) or fragile health financing show stagnant or rising DALYs, highlighting the dependence of chronic IBD outcomes on continuous drug and surgical supply chains. Psychiatric comorbidity (e.g., anxiety, depression) likely amplifies the nonfatal burden of IBD by worsening disease control and quality of life; if unmeasured, YLD may be underestimated [35,36]. We highlight the need for harmonized metrics that capture co-occurring mental health conditions and their incremental disability. Although immortal time bias pertains to exposure–outcome cohort studies, time-related biases relevant to burden trends—shifts in coding/case definitions, expansion of diagnostic capacity, and survival gains inflating prevalence—remain salient [37].

5.5. Implications for policy and practice

The surge in incidence among younger adults foreshadows decades of productivity loss and escalating demand for complex, lifelong care. Health-system planners must rapidly expand gastroenterology training, endoscopic capacity, and equitable financing mechanisms for advanced therapeutics—particularly in South and Central Asia where growth is fastest and service coverage weakest [38]. The steep decline in age-standardised DALY rates in East and Southeast Asia demonstrates that integrated chronic-care models, timely introduction of biologics, and proactive colorectal-cancer surveillance can translate rising prevalence into proportionally smaller disability burdens. Replicating these models in lagging regions will be critical to averting a widening equity gap[39,40]. At the same time, the plateau projected for Southeast Asia offers a strategic window to consolidate registries and strengthen primary-care pathways before the next epidemiological wave [41].

5.6. Strengths and limitations

Key strengths include the use of the most recent GBD iteration, harmonized methodology enabling cross-country comparison, and the application of Bayesian age-period-cohort models that incorporate cohort drift into long-range projections. Limitations stem from the GBD's reliance on sparse primary data for many low-income settings, necessitating covariate-based borrowing of strength that may misclassify local trends. Our forecasts assume continuity in exposure trajectories and health-system performance; disruptive events—pandemics, wars, novel therapeutics—could shift future burden outside the projected uncertainty ranges. The aggregated nature of GBD data precluded assessment of phenotype (Crohn's vs ulcerative colitis), extra-intestinal manifestations and treatment patterns that influence patient-level outcomes [42]. Methodological limitations of the decomposition. Our Das-Gupta decomposition is an accounting tool, not a causal model. It partitions observed changes into population growth, ageing, and epidemiologic change under an additive assumption; in reality, these drivers are interdependent (e.g., ageing × detection capacity), and such interactions are absorbed into the “epidemiologic” component. Future work should incorporate health-system covariates and interaction-aware attribution (e.g., Shapley/counterfactual methods) with uncertainty propagation. We acknowledge that part of the observed rise in IBD incidence and prevalence may reflect improved diagnostic capacity rather than a true epidemiologic surge. Over the past three decades, many Asian countries—particularly China and several Gulf states—have rapidly expanded gastroenterology services, endoscopic infrastructure, and physician awareness, leading to greater detection of previously underdiagnosed cases. The Global Burden of Disease (GBD) framework attempts to harmonize heterogeneous data sources, but residual ascertainment bias across health systems remains inevitable. Consequently, increases in age-standardized rates should be interpreted with caution, as they likely capture both genuine disease emergence and enhanced case identification. Future work integrating healthcare access indicators (e.g., colonoscopy rates, specialist density, diagnostic registry coverage) could help disentangle true epidemiologic trends from detection-related artifacts.

5.7. Future research

Prospective, population-based cohort studies across understudied Asian regions should disentangle the contributions of genetics, microbiota and environmental exposures to the emerging IBD epidemic. Implementation science is needed to evaluate scalable models of chronic IBD care in low-resource settings. Moreover, integration of real-world biologic utilization data into future GBD updates would refine DALY estimation and allow benchmarking of therapeutic equity [43].

6. Conclusions

Asia is undergoing a complex epidemiological transition in inflammatory bowel disease: incidence and prevalence continue to rise in most sub-regions, yet improved clinical management is driving down mortality and disability. Without concerted investment in registries, specialist capacity and equitable access to advanced therapies, large segments of the Asian population may face unchecked morbidity. Policymakers must therefore prepare for a sustained, though regionally heterogeneous, IBD burden that will test health-system resilience for decades to come.

CRediT authorship contribution statement

Kui Wang: Writing – original draft, Visualization, Methodology, Formal analysis, Data curation, Conceptualization. Yunqing Zeng: Writing – original draft, Visualization, Validation, Software, Methodology, Investigation, Formal analysis, Data curation, Conceptualization. Shanshan Zhang: Writing – review & editing, Validation, Supervision, Software, Resources, Project administration, Formal analysis, Data curation, Conceptualization. Yanqing Li: Writing – review & editing, Writing – original draft, Validation, Supervision, Resources, Project administration, Methodology, Investigation, Data curation, Conceptualization.

Availability of data and materials

All data analysed in the present study are publicly available from the Global Burden of Disease 2021 repository (Institute for Health Metrics and Evaluation). The full dataset can be accessed and downloaded at https://ghdx.healthdata.org/gbd-2021.

Funding

This study was supported by grants from the Shandong Provincial Clinical Research Center for Digestive Diseases, and the National Natural Science Foundation of China (82270580、82470571).

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Handling Editor: Y Renaudineau

Appendix A. Supplementary data

The following are the Supplementary data to this article.

figs1.

Data availability

Data will be made available on request.