Global burden and cross-country inequalities of age-related eye diseases from 1990 to 2021: a comprehensive analysis of temporal trends and socioeconomic disparities

To evaluate the global burden of blindness and vision loss (BVL) from 1990 to 2021 using a retrospective analysis of epidemiological data from Global Burden of Disease (GBD) study 2021 and to project trends over the next 15 years. This retrospective study analyzed data on years lived with disability (YLDs) and prevalence across 204 countries and territories. Trends over time were assessed using estimated annual percentage change (EAPC) of the age-standardized rates (ASR), while decomposition analysis quantified the contributions of population aging, growth, and epidemiological shifts. Socioeconomic disparities were evaluated using the Slope Index of Inequality and the Concentration Index. Future trends in age-standardized prevalence rates (ASPR) and age-standardized YLDs rates (ASYR) were projected using Bayesian age-period-cohort modeling. Between 1990 and 2021, global YLDs due to BVL more than doubled, increasing from 14.31 to 29.16 million. The prevalence of BVL surged by 246.8%, with a disproportionately higher burden observed among females. Regions with low to middle Socio-Demographic Index (SDI) scores exhibited the highest ASPR and ASYR. Population growth and aging were the primary drivers of the increasing burden, while epidemiological trends had mixed effects. Significant socioeconomic disparities persist, with a higher concentration of BVL burden in economically disadvantaged regions. Projections indicate a continued increase in BVL burden through 2036, particularly among women and older populations. Despite advancements in healthcare, the global burden of BVL has substantially increased over the past 32 years, driven by demographic and socioeconomic factors. Persistent disparities highlight the urgent need for targeted public health interventions, equitable resource allocation, and policy initiatives to address the growing impact of BVL worldwide.

This study examined the global and regional temporal changes in cross-country inequalities of site-specific osteoarthritis (OA) burden from 1990 to 2021. Age-standardized years lived with disability rates (ASYRs) for site-specific OA across 204 countries and territories were obtained from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021. The slope index of inequality (SII) and the concentration index (CCI) were calculated to quantify the absolute and relative cross-country inequalities. Average annual percent change (AAPC) was used to assess the temporal changes. From 1990 to 2021, the ASYR of OA increased regardless of the joint affected globally. The SII of total OA exhibited an improving cross-country inequality among higher sociodemographic index (SDI) countries and territories, decreasing from 77.26 (95% confidence interval [CI] 69.32-85.20) to 69.85 (95% CI 60.67-79.02). Similarly, the CCI of total OA decreased from 0.0815 (95% CI 0.0732-0.0897) to 0.0622 (95% CI 0.0551-0.0693). However, most regions exhibited worsening cross-country inequalities among higher SDI countries and territories. Central sub-Saharan Africa showed the largest worsening inequality in SII (AAPC 4.55, 95% CI 2.83-6.29), whereas east Asia showed the largest worsening inequality in CCI (AAPC 1.96, 95% CI 1.48-2.43). Hand OA showed consistently improving absolute and relative cross-country inequalities among higher SDI countries and territories, whereas other OA showed consistently worsening inequalities. The cross-country inequalities of OA burden have persisted and even worsened in some regions over the past decades. Targeted prevention and management strategies according to geographic location and affected joint are pivotal to reduce the growing OA burden and achieve equity in health outcomes.

BackgroundAs a common complication of chronic kidney disease (CKD), anemia is associated with increased mortality and reduced quality of life. Despite its severe impact, there is a lack of high-quality data on the global burden of anemia attributed to CKD. This study aims to provide a comprehensive analysis of the anemia burden attributed to CKD.MethodsUsing data from the Global Burden of Disease study (GBD) 2021, we report the prevalence and years lived with disability (YLDs) of anemia attributed to CKD across different sexes, ages, and regions; assess the association between anemia burden attributed to CKD and the socio-demographic index (SDI); and quantify and predict temporal trends of anemia burden attributed to CKD.ResultsIn 2021, there were 63.75 million (95% uncertainty interval [UI]: 59.05 to 68.37) cases and 1.70 million (95% UI: 1.13 to 2.43) YLDs of anemia attributed to CKD globally. Compared with 1990, the prevalence and YLDs increased by 96.24 and 74.78%, respectively, which was largely driven by population growth and aging. The global age-standardized prevalence rate (ASPR) and YLD rate per 100,000 were 762.12 (95% UI: 707.32 to 817.37) and 20.34 (95% UI: 13.54 to 29.09) in 2021, which decreased by 9.39 and 18.93% in comparison with those in 1990. However, the decline in ASPR stagnated after 2010, with a slight increase observed between 2010 and 2015. A negative relationship between SDI and the anemia burden attributed to CKD was observed at both regional and national levels. Women had higher ASPR and age-standardized YLD rates compared to men, and the burden attributed to CKD increased with age. Predictive analysis indicated that the prevalence of cases will continue to rise, while the YLDs, ASPR, and age-standardized YLD rates are expected to decline consistently.ConclusionAnemia attributed to CKD is a major public health issue across the world, with persistent regional and socioeconomic disparities. Continued efforts, including addressing socioeconomic disparities, improving access to healthcare, and innovative treatments, are essential to reduce the anemia burden attributed to CKD.

This research aimed to assess the trends in the burden of age-related macular degeneration (AMD) in the Eastern Mediterranean Region (EMR) by age, sex, socio-demographic index (SDI), and location. We extracted data on the prevalence and years lived with disability (YLDs) of AMD from the Global Burden of Disease (GBD) study 2021. The data included all 22 countries in the EMR from 1990 to 2021. Estimates were presented as counts, age-standardized rates per 100,000, and their corresponding 95% uncertainty intervals (UIs). In 2021, the EMR had an age-standardized point prevalence for AMD of 196.8 (95% UI: 161.5 to 240.2) and a YLD rate of 14.9 (10.3 to 20.5) per 100,000 individuals, which represents a decline of 8.1% (from − 11.1% to -5.0%) and 13.3% (from − 16.7% to -9.7%), respectively, when compared to the data from 1990. In 2021, Iran exhibited the highest age-standardized YLD rate at 25.0 (17.2 to 34.9), while Somalia recorded the lowest rate at 8.0 (5.2 to 11.8). Notably, all countries within the EMR demonstrated a reduction in their age-standardized YLD rates from 1990 to 2021, except Yemen. We found an M-shaped relationship between AMD burden and the SDI during 1990–2021. The burden initially increased until reaching an SDI of 0.3, followed by a decline to 0.4, then rose again, peaking at an SDI of 0.6, before showing a final descending trend at SDI values. Despite a reduction in the burden of AMD over the past thirty years, its prevalence continues to be remarkable. Our findings revealed that women experienced a greater burden of AMD than men in the EMR. Additionally, this study highlighted a reduction in age-standardized prevalence and YLD rates. These insights can serve as a foundational basis for developing policies aimed at preventing and treating AMD.

BackgroundAnemia remains a significant global health challenge, disproportionately affecting women of reproductive age (WRA, 15 to 49 years) due to physiological and socioeconomic factors. However, there is a lack of high-quality data on anemia burden and causes analysis in this population. The aim of this study is to provide a comprehensive global assessment of anemia burden and its underlying causes among WRA.MethodsUsing data from the Global Burden of Disease Study (GBD) 2021, we evaluated the prevalence, years lived with disability (YLDs), and underlying causes of anemia among WRA at global, regional, and national levels. We also evaluated the association between anemia burden and the socio-demographic index (SDI), quantified temporal trends of anemia burden from 1990 to 2021, and projected future burden to 2030.ResultsGlobally in 2021, there were 657.09 million (95% uncertainty interval [UI]: 643.59 to 671.22) anemia cases and 18.07 million (95% UI: 12.00 to 26.17) YLDs among WRA. The global age-standardized prevalence rates (ASPR) and YLDs rates per 100,000 were 33,716.77 (95% UI: 33,023.84 to 34,441.71) and 927.03 (95% UI: 615.40 to 1,342.99) in 2021, and they decreased by 0.181% and 0.539% annually from 1990 to 2021, respectively. However, the decline in ASPR stagnated after 2009, with a slight increase observed through 2021, primarily driven by rising mild anemia. An inverse relationship existed between SDI and anemia burden across regions and nations. The most common causes of anemia were dietary iron deficiency, hemoglobinopathies and hemolytic anemias, and other neglected tropical diseases, with HIV/AIDS and malaria being most prominent in specific regions. Projections indicate anemia cases and YLD counts will rise consistently from 2022 to 2030, while ASPR and age-standardized YLD rates will decline.ConclusionAnemia among WRA is a major public health burden worldwide with persistent regional and socioeconomic disparities. Mitigating this burden requires continued efforts addressing underlying causes, reducing socioeconomic inequities, and improving access to healthcare and nutritional interventions.

Trends and cross-country inequalities in global burns burden among children and adolescents: A population-based study from 1990 to 2021.

BackgroundCervical (CC), ovarian (OC), and uterine (UC) cancers are major contributors to global gynecological cancer (GC) burden. This research intended to update trends in disease burden and care quality for these cancers and quantify cross-country inequalities between 1990 and 2021.MethodsWe performed a secondary analysis utilizing the Global Burden of Disease 2021 database. Disease burden and care quality were evaluated through age-standardized incidence rates (ASIR), age-standardized years lived with disability rates (ASYR), and quality-of-care index (QCI). Trends were analyzed using estimated annual percentage changes, while absolute and relative cross-country inequalities were quantified using the slope index of inequality and concentration index.ResultsFrom 1990 to 2021, global ASIR and ASYR for CC and OC declined, whereas UC showed an increase in both rates. Concurrently, a general uptrend in QCI was observed for all three GCs. Across the WHO regions, the European region reported the highest ASIR and ASYR for OC and UC in 2021, and the African region recorded the highest for CC. In both 1990 and 2021, countries/territories with higher socio-demographic index (SDI) experienced a higher ASYR for OC and UC, while CC primarily concentrated in lower SDI countries/territories. Significant healthcare inequalities in age-standardized QCI were observed, with higher SDI countries/territories generally exhibiting better QCI.ConclusionTrends in the burden and QCI for gynecological cancers demonstrated significant disparities among WHO regions and 204 countries/territories, with global inequalities persisting. Urgent action is needed to develop geographically tailored strategies for equitable access to high-quality healthcare.

Data sourcesThe Global Burden of Diseases, Injuries, and Risk Factors study (GBD) 2019.BackgroundTo describe burden, and to explore cross-country inequalities according to socio-demographic index (SDI) for stroke and subtypes attributable to diet.MethodsDeath and years lived with disability (YLDs) data and corresponding estimated annual percentage changes (EAPCs) were estimated by year, age, gender, location and SDI. Pearson correlation analysis was performed to evaluate the connections between age-standardized rates (ASRs) of death, YLDs, their EAPCs and SDI. We used ARIMA model to predict the trend. Slope index of inequality (SII) and relative concentration index (RCI) were utilized to quantify the distributive inequalities in the burden of stroke.ResultsA total of 1.74 million deaths (56.17% male) and 5.52 million YLDs (55.27% female) attributable to diet were included in the analysis in 2019.Between 1990 and 2019, the number of global stroke deaths and YLDs related to poor diet increased by 25.96% and 74.76% while ASRs for death and YLDs decreased by 42.29% and 11.34% respectively. The disease burden generally increased with age. The trends varied among stroke subtypes, with ischemic stroke (IS) being the primary cause of YLDs and intracerebral hemorrhage (ICH) being the leading cause of death. Mortality is inversely proportional to SDI (R = -0.45, p < 0.001). In terms of YLDs, countries with different SDIs exhibited no significant difference (p = 0.15), but the SII changed from 38.35 in 1990 to 45.18 in 2019 and the RCI showed 18.27 in 1990 and 24.98 in 2019 for stroke. The highest ASRs for death and YLDs appeared in Mongolia and Vanuatu while the lowest of them appeared in Israel and Belize, respectively. High sodium diets, high red meat consumption, and low fruit diets were the top three contributors to stroke YLDs in 2019.DiscussionThe burden of diet-related stroke and subtypes varied significantly concerning year, age, gender, location and SDI. Countries with higher SDIs exhibited a disproportionately greater burden of stroke and its subtypes in terms of YLDs, and these disparities were found to intensify over time. To reduce disease burden, it is critical to enforce improved dietary practices, with a special emphasis on mortality drop in lower SDI countries and incidence decline in higher SDI countries.

BackgroundOsteoarthritis (OA) is a common orthopedic disorder, and its incidence has been increasing among young adults in recent years. The purpose of this study is to investigate the global, regional, and national trends in OA burden and variation among individuals aged 30 to 44 from 1990 to 2019.MethodsData on the incidence, prevalence, and years lived with disability (YLDs) related to OA were sourced from the Global Burden of Disease Study 2019 among individuals aged 30 to 44. These measures were stratified by gender, region, country, and socio-demographic index (SDI). Additionally, we analyzed YLDs attributable to risk factors.ResultsIn 2019, there were a total of 32,971,701 cases of OA among individuals aged 30 to 44 years worldwide, with an additional 7,794,008 new incident cases reported. OA of the knee was the primary contributor to both incidence and prevalence rates over the past three decades. From 1990 to 2019, both males and females in countries with high SDI and high-middle SDI showed upward trends in age-standardized incidence, prevalence, and YLDs rates. In 2019, the United States of America had the highest age-standardized incidence, prevalence, and YLDs rates. Elevated body-mass index (BMI) was found to be the most prevalent risk factor for osteoarthritis-related YLDs. Age-standardized YLDs rates were positively associated with SDI.ConclusionsOA remains a significant disease burden on individuals aged 30 to 44, with modifiable risk factors such as unhealthy lifestyle and obesity representing key targets for future interventions aimed at reducing the impact of this condition on younger generations.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12891-024-07442-w.

BackgroundAppendicitis is the most common abdominal surgical emergency worldwide, and its burden has been changing. We report the level and trends of appendicitis prevalence, and incidence; and years lived with disability (YLD) in 204 countries and territories from 1990 to 2019, based on data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019.MethodsThe numbers and age-standardized prevalence, incidence, and YLD rates per 100,000 population of appendicitis were estimated across regions and countries by age, sex, and sociodemographic index (SDI). All the estimates were reported with 95% uncertainty intervals (UIs).ResultsGlobally, the age-standardized prevalence and incidence rates of appendicitis in 2019 were 8.7 (95% UI 6.9 to 11.0) and 229.9 (95% UI 180.9 to 291.0) per 100,000 population, with increases of 20.8% (95% UI 18.9 to 23.0%) and 20.5% (95% UI 18.7 to 22.8%) from 1990 to 2019, respectively. Additionally, the age-standardized YLDs rate was 2.7 (95% UI 1.8 to 3.9) in 2019, with an increase of 20.4% (95% UI 16.2 to 25.1%) from 1990 to 2019. 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. However, no statistically significant differences were observed between the male and female individuals in all groups. Ethiopia, India, and Nigeria showed the largest increases in the age-standardized prevalence rate between 1990 and 2019. Generally, positive associations were found between the age-standardized YLD rates and SDI at the regional and national levels.ConclusionsAppendicitis remains a major public health challenge globally. Increasing awareness of appendicitis and its risk factors and the importance of early diagnosis and treatment is warranted to reduce its the burden.

Background Hearing loss is a global health issue affecting millions and imposing a significant burden. This study aimed to retrospectively and predictively assess the prevalence and years lived with disability (YLDs) due to hearing loss, stratified by sociodemographic index (SDI), age, and sex. Methods Data from the 2021 Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) were used to analyze the prevalence and YLD burden of hearing loss across different subgroups. Age-standardized prevalence rates (ASPR), age-standardized YLD rates (ASYR), and estimated annual percentage changes (EAPCs) were calculated to assess trends. Results In 2021, over 1.5 billion individuals had hearing loss, resulting in significant disability burden. EAPCs for ASPR and ASYR from 1990 to 2021 were 0.16 (95% confidence intervals [CI]: 0.15-0.17) and 0.17 (0.16-0.18) respectively. Regions with middle SDI had the highest prevalence, ASPR, YLDs, and ASYR, while high SDI regions had the lowest. ASYR and ASPR were negatively correlated with SDI across regions in most regions. Males had significantly higher ASPR and ASYR than females. ASPR and ASYR increased with age. Projections from 2022 to 2050 indicated a continued rise in ASPR, with a slight decline in ASYR. Conclusions Hearing loss burden increased from 1990 to 2021, with notable differences across regions, genders, and age groups. High SDI areas had the lowest burden, while middle SDI regions experienced the most severe hearing loss. Low SDI areas had a higher disability ratio relative to prevalence. Males and older adults bore a disproportionately high burden of hearing loss.

Headache disorders significantly impact health and functioning, yet studies on their global burden across all age groups are limited. This study utilizes data from the Global Burden of Disease (GBD) 2021 to investigate the global burden of headache disorders. This analysis draws on GBD 2021 data, covering 204 countries and territories. We investigated the prevalence, incidence, and DALYs for headache disorders from 1990 to 2021, calculating Estimated Annual Percentage Change (EAPC) to analyze temporal trends. Additionally, decomposition analysis was used to evaluate the contributions of aging, population growth, and epidemiological changes. The slope index of inequality and concentration index were employed to assess inequalities in disease burden. From 1990 to 2021, the global prevalence of headache disorders increased significantly, reaching approximately 2.81 billion cases in 2021, a 57.16% increase from approximately 1.79 billion cases in 1990. During this period, the global Age-Standardized Prevalence Rate (ASPR) and Age-Standardized DALY Rate (ASDR) both showed gradual increases, while the Age-Standardized Incidence Rate (ASIR) remained stable, with EAPC values of 0.01, 0.04 and-0.0002, respectively. High Socio-demographic Index (SDI) regions exhibited the highest rates of ASPR, ASIR, and ASDR, whereas Middle SDI regions experienced the fastest growth, with EAPC values of 0.17, 0.17, and 0.18, respectively. The SDI exhibited significant positive correlations with the EAPC of ASPR (R = 0.18, p = 0.0093) and ASIR (R = 0.16, p = 0.027). Decomposition analysis identified population growth as the primary driver in regions with increasing disease burden. The slope index of inequality (SII) shows that disparities in ASPR, ASIR, and ASDR slightly increased from 7,648.13, 2,506.76, and 88.45 in 1990 to 7,851.55, 2,557.94, and 100.38 in 2021. In contrast, the concentration index (CI) in 2021 were 0.05, 0.05, and 0.04, showing no significant change from 1990. Headache disorders continue to impose a growing burden globally, with marked regional and socio-economic disparities. Addressing these trends requires targeted public health interventions, particularly in high-burden and low-resource settings.

Background Near vision loss (NVL), primarily resulting from presbyopia and other age-related conditions, significantly reduces quality of life and imposes a substantial global economic burden. However, research on NVL’s prevalence and determinants remains limited, particularly in Belt and Road Initiative (BRI) countries. This study aims to analyze the disease burden and temporal trends of NVL in BRI countries. Methods Using data from the Global Burden of Disease 2021 (GBD 2021) study, we examined age-standardized prevalence rates (ASPR) and age-standardized years lived with disability rates (ASYLDR) for NVL across BRI countries from 1990 to 2021. Analyses were stratified by Socio-Demographic Index (SDI) quintiles, and joinpoint regression was employed to estimate the average annual percentage change (AAPC) in disease burden from 1990 to 2021. Results Between 1990 and 2021, South Asia (ASPR: 20,747.02/105; ASYLDR: 208.01/105) and East Asia (ASPR: 15,509.26/105; ASYLDR: 157.57/105) recorded the highest ASPR and ASYLDR, while Western Europe reported the lowest (ASPR: 5,912.94/105; ASYLDR: 59.38/105). Among BRI countries, the Philippines, Nepal, and India exhibited the highest NVL burden, whereas Malaysia reported the lowest. NVL prevalence and YLDs increased with age, peaking at ages 60–64 and 55–59, respectively. Additionally, ASPR and ASYLDR were negatively correlated with SDI (R = -0.467 and R = -0.462, p &lt; 0.01). Conclusions NVL burden varies across BRI countries based on age, gender, and SDI level. Older women in low SDI regions are particularly at risk. International collaboration, public health outreach, and targeted interventions are essential to reduce the global NVL burden.

This study aims to systematically elucidate the burden of blindness and vision loss (BVL) attributable to smoking from 1990 to 2021 and to forecast the trends in BVL burden over the next decade. We extracted data on years lived with disability (YLDs) and age-standardized YLDs rate (ASYR) related to blindness and vision loss (BVL) caused by smoking, including cataracts and age-related macular degeneration (AMD), from the Global Burden of Disease (GBD) database for the years 1990 to 2021. These data were disaggregated by age, gender, sociodemographic index (SDI), region, and country. Temporal trends in the burden of smoking-induced BVL were evaluated by calculating the average annual percentage changes (AAPCs). BVL attributable to smoking presents a significant disease burden, with global BVL-related YLDs attributable to smoking increasing from 1990 to 2021, while ASYR showed a declining trend. In 2021, the global BVL-related YLDs and ASYR attributable to smoking were estimated at 284.03 thousand and 3.27 per 100,000 population. The ASYR for cataract and AMD are 2.60 and 0.68 per 100,000, respectively. The burden was notably higher in males than females, highlighting significant gender disparities. Regionally, the highest burdens were observed in South Asia, Southeast Asia, and North Africa. It is expected that the number of global BVL-related YLDs will increase further by 2030. Smoking has imposed a substantial disease burden on BVL over the past three decades. The burden is predominantly concentrated among males, particularly older individuals and those in low to middle-SDI regions. Moreover, the burden of smoking-induced BVL is expected to continue improving over the next decade.

This study aims to assess the disease burden and care quality along with cross-country inequalities for stroke at global, regional, and national levels from 1990 to 2021. Data on stroke were extracted from the Global Burden of Disease (GBD) study 2021 for the globe, five sociodemographic index (SDI) regions, 21 GBD regions, and 204 countries/territories. The disease burden was quantified using the age-standardized disability-adjusted life years rate (ASDR). Quality of care (QoC) was evaluated through the age-standardized QoC index (QCI). To assess cross-country disparities in both disease burden and age-standardized QCI, the slope index of inequality (SII) and the concentration index were utilized. From 1990 to 2021, the global ASDR of stroke decreased from 3078.95 (95% uncertainty interval [UI]: 2893.58, 3237.34) to 1886.20 (95% UI: 1738.99, 2017.90) per 100,000 population, while the age-standardized QCI improved from 50.79 to 64.61. However, the results of inequalities showed worsening inequalities in both ASDR and QCI, with lower SDI countries shouldering a disproportionate burden and higher SDI countries maintaining higher QoC. The SII and concentration index for ASDR indicated a worsening inequality among lower SDI countries, with SII increasing to -2616.44 and the concentration index increasing to -0.1119 in 2021. Meanwhile, the SII and concentration index for age-standardized QCI showed a worsening inequality among higher SDI countries, with SII of 27.48 and concentration index of 0.0922 in 2021. Despite notable global advancements, significant disparities in stroke still exist, particularly in lower SDI regions facing high disease burdens and substandard care.