Global maternal mortality projections by urban/rural location and education level: a simulation-based analysis.

Background: Maternal mortality remains a challenge in global health, with well-known disparities across countries. However, less is known about disparities in maternal health by subgroups within countries. The aim of this study is to estimate maternal health indicators for subgroups of women within each country. Methods: In this simulation-based analysis, we used the empirically calibrated Global Maternal Health (GMatH) microsimulation model to estimate a range of maternal health indicators by subgroup (urban/rural location and level of education) for 200 countries/territories from 1990 to 2050. Education levels were defined as low (less than primary), middle (less than secondary), and high (completed secondary or higher). The model simulates the reproductive lifecycle of each woman, accounting for individual-level factors such as family planning preferences, biological factors (e.g., anemia), and history of maternal complications, and how these factors vary by subgroup. We also estimated the impact of scaling up women's education on projected maternal health outcomes compared to clinical and health system-focused interventions. Findings: We find large subgroup differences in maternal health outcomes, with an estimated global maternal mortality ratio (MMR) in 2022 of 292 (95% UI 250-341) for rural women and 100 (95% UI 84-116) for urban women, and 536 (95% UI 450-594), 143 (95% UI 117-174), and 85 (95% UI 67-108) for low, middle, and high education levels, respectively. Ensuring all women complete secondary school is associated with a large impact on the projected global MMR in 2030 (97 [95% UI 76-120]) compared to current trends (167 [95% UI 142-188]), with especially large improvements in countries such as Afghanistan, Chad, Madagascar, Niger, and Yemen. Interpretation: Substantial subgroup disparities present a challenge for global maternal health and health equity. Outcomes are especially poor for rural women with low education, highlighting the need to ensure that policy interventions adequately address barriers to care in rural areas, and the importance of investing in social determinants of health, such as women's education, in addition to health system interventions to improve maternal health for all women. Funding: John D. and Catherine T. MacArthur Foundation, 10-97002-000-INP.

Cost-effectiveness of Improved WIC Food Package for Preventing Childhood Obesity.

BACKGROUND AND OBJECTIVES: The Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) prevents food insecurity and supports nutrition for more than 3 million low-income young children. Our objectives were to determine the cost-effectiveness of changes to WIC's nutrition standards in 2009 for preventing obesity and to estimate impacts on socioeconomic and racial/ethnic inequities. METHODS: We conducted a cost-effectiveness analysis to estimate impacts from 2010 through 2019 of the 2009 WIC food package change on obesity risk for children aged 2 to 4 years participating in WIC. Microsimulation models estimated the cases of obesity prevented in 2019 and costs per quality-adjusted-life year gained. RESULTS: An estimated 14.0 million 2- to 4-year old US children (95% uncertainty interval (UI), 13.7-14.2 million) were reached by the updated WIC nutrition standards from 2010 through 2019. In 2019, an estimated 62 700 (95% UI, 53 900-71 100) cases of childhood obesity were prevented, entirely among children from households with low incomes, leading to improved health equity. The update was estimated to cost $10 600 per quality-adjusted-life year gained (95% UI, $9760-$11 700). If WIC had reached all eligible children, more than twice as many cases of childhood obesity would have been prevented. CONCLUSIONS: Updates to WIC's nutrition standards for young children in 2009 were estimated to be highly cost-effective for preventing childhood obesity and contributed to reducing socioeconomic and racial/ethnic inequities in obesity prevalence. Improving nutrition policies for young children can be a sound public health investment; future research should explore how to improve access to them.

Cost Effectiveness of Calorie Labeling at Large Fast-Food Chains Across the U.S.

INTRODUCTION: Calorie labeling of standard menu items has been implemented at large restaurant chains across the U.S. since 2018. The objective of this study was to evaluate the cost effectiveness of calorie labeling at large U.S. fast-food chains. METHODS: This study evaluated the national implementation of calorie labeling at large fast-food chains from a modified societal perspective and projected its cost effectiveness over a 10-year period (2018-2027) using the Childhood Obesity Intervention Cost-Effectiveness Study microsimulation model. Using evidence from over 67 million fast-food restaurant transactions between 2015 and 2019, the impact of calorie labeling on calorie consumption and obesity incidence was projected. Benefits were estimated across all racial, ethnic, and income groups. Analyses were performed in 2022. RESULTS: Calorie labeling is estimated to be cost saving; prevent 550,000 cases of obesity in 2027 alone (95% uncertainty interval=518,000; 586,000), including 41,500 (95% uncertainty interval=33,700; 50,800) cases of childhood obesity; and save $22.60 in healthcare costs for every $1 spent by society in implementation costs. Calorie labeling is also projected to prevent cases of obesity across all racial and ethnic groups (range between 126 and 185 cases per 100,000 people) and all income groups (range between 152 and 186 cases per 100,000 people). CONCLUSIONS: Calorie labeling at large fast-food chains is estimated to be a cost-saving intervention to improve long-term population health. Calorie labeling is a low-cost intervention that is already implemented across the U.S. in large chain restaurants.

A Sugar-Sweetened Beverage Excise Tax in California: Projected Benefits for Population Obesity and Health Equity.

INTRODUCTION: Amid the successes of local sugar-sweetened beverage (SSB) taxes, interest in state-wide policies has grown. This study evaluated the cost effectiveness of a hypothetical 2-cent-per-ounce excise tax in California and its implications for population health and health equity. METHODS: Using the Childhood Obesity Intervention Cost-Effectiveness Study microsimulation model, tax impacts on health, health equity, and cost effectiveness over 10 years in California were projected, both overall and stratified by race/ethnicity and income. Expanding on previous models, differences in the effect of intake of SSBs on weight by BMI category were incorporated. Costing was performed in 2020, and analyses were conducted in 2021-2022. RESULTS: The tax is projected to save $4.55 billion in healthcare costs, prevent 266,000 obesity cases in 2032, and gain 114,000 quality-adjusted life years. Cost-effectiveness metrics, including cost/quality-adjusted life year gained, were cost saving. Spending on SSBs was projected to decrease by $33 per adult and $26 per child overall in the first year. Reductions in obesity prevalence for Black and Hispanic Californians were 1.8 times larger than for White Californians, and reductions for adults with lowest incomes (<130% Federal Poverty Level) were 1.4 times the reduction among those with highest incomes (>350% Federal Poverty Level). The tax is projected to save $112 in obesity-related healthcare costs per $1 invested. CONCLUSIONS: A state-wide SSB tax in California would be cost saving, lead to reductions in obesity and improvement in SSB-related health equity, and lead to overall improvements in population health. The policy would generate more than $1.6 billion in state tax revenue annually that can also be used to improve health equity.

Treat All versus targeted strategies to select HBV-infected people for antiviral therapy in The Gambia, west Africa: a cost-effectiveness analysis.

BACKGROUND: Global elimination of hepatitis B virus (HBV) requires expanded uptake of antiviral therapy, potentially by simplifying testing algorithms, especially in resource-limited countries. We evaluated the effectiveness, cost-effectiveness, and budget impact of three strategies that determine eligibility for anti-HBV treatment, as compared with the WHO 2015 treatment eligibility criteria, in The Gambia. METHODS: We developed a microsimulation model of natural history using data from the Prevention of Liver Fibrosis and Cancer in Africa programme (known as PROLIFICA) in The Gambia, for an HBV-infected cohort of individuals aged 20 years. The algorithms included in the model were a conventional strategy using the European Association for the Study of the Liver (EASL) 2017 criteria, a simplified algorithm using hepatitis B e antigen and alanine aminotransferase (the Treatment Eligibility in Africa for the Hepatitis B Virus [TREAT-B] score), a Treat All approach for all HBV-infected individuals, and the WHO 2015 criteria. Outcomes to measure effectiveness were disability-adjusted life years (DALYs) and years of life saved (YLS), which were used to calculate incremental cost-effectiveness ratios (ICERs) with the WHO 2015 criteria as the base-case scenario. Costs were assessed from a modified social perspective. A budget impact analysis was also done. We tested the robustness of results with a range of sensitiviy analyses including probabilistic sensitivity analysis. FINDINGS: Compared with the WHO criteria, TREAT-B resulted in 4877 DALYs averted and Treat All resulted in 9352 DALYs averted, whereas the EASL criteria led to an excess of 795 DALYs. TREAT-B was cost-saving, whereas the ICER for Treat All (US$2149 per DALY averted) was higher than the cost-effectiveness threshold for The Gambia (0·5 times the country's gross domestic product per capita: $352). These patterns did not change when YLS was the outcome. In a modelled cohort of 5000 adults (aged 20 years) with chronic HBV infection from The Gambia, the 5-year budget impact was $1·14 million for Treat All, $0·66 million for TREAT-B, $1·03 million for the WHO criteria, and $1·16 million for the EASL criteria. Probabilistic sensitivity analysis indicated that among the Treat All, EASL, and TREAT-B algorithms, Treat All would become the most preferred strategy only with a willingness-to-pay threshold exceeding approximately $72 000 per DALY averted or $110 000 per YLS. INTERPRETATION: Although the Treat All strategy might be the most effective, it is unlikely to be cost-effective in The Gambia. A simplified strategy such as TREAT-B might be a cost-saving alternative. FUNDING: UK Research and Innovation (Medical Research Council). TRANSLATION: For the French translation of the abstract see Supplementary Materials section.

Social media platforms generate billions of dollars in revenue from U.S. youth: Findings from a simulated revenue model.

Social media platforms are suspected to derive hefty profits from youth users who may be vulnerable to negative mental health outcomes, including depression, anxiety, and eating disorders. Platforms, however, are not required to make these data publicly available, which may limit the abilities of researchers and policymakers to adequately investigate and regulate platform practices. This study aimed to estimate the number of U.S.-based child (0-12 years old) and adolescent (13-17 years old) users and the annual advertising revenue generated from youth across six major platforms. Data were drawn from public survey and market research sources conducted in 2021 and 2022. A simulation analysis was conducted to derive estimates of the number of users and the annual advertising revenue per age group and overall (ages 0-17 years) for 2022. The findings reveal that, across six major social media platforms, the 2022 annual advertising revenue from youth users ages 0-17 years is nearly $11 billion. Approximately 30-40% of the advertising revenue generated from three social media platforms is attributable to young people. Our findings highlight the need for greater transparency from social media platforms as well as regulation of potentially harmful advertising practices that may exploit vulnerable child and adolescent social media users.

The societal costs and health impacts on obesity of BMI report cards in US schools.

OBJECTIVE: This study aimed to estimate the 10-year cost-effectiveness of school-based BMI report cards, a commonly implemented program for childhood obesity prevention in the US where student BMI is reported to parents/guardians by letter with nutrition and physical activity resources, for students in grades 3 to 7. METHODS: A microsimulation model, using data inputs from evidence reviews on health impacts and costs, estimated: how many students would be reached if the 15 states currently measuring student BMI (but not reporting to parents/guardians) implemented BMI report cards from 2023 to 2032; how many cases of childhood obesity would be prevented; expected changes in childhood obesity prevalence; and costs to society. RESULTS: BMI report cards were projected to reach 8.3 million children with overweight or obesity (95% uncertainty interval [UI]: 7.7-8.9 million) but were not projected to prevent any cases of childhood obesity or significantly decrease childhood obesity prevalence. Ten-year costs totaled $210 million (95% UI: $30.5-$408 million) or $3.33 per child per year with overweight or obesity (95% UI: $3.11-$3.68). CONCLUSIONS: School-based BMI report cards are not cost-effective childhood obesity interventions. Deimplementation should be considered to free up resources for implementing effective programs.

State-Specific Prevalence of Severe Obesity Among Adults in the US Using Bias Correction of Self-Reported Body Mass Index.

INTRODUCTION: Adults with severe obesity are at increased risk for poor metabolic health and may need more intensive clinical and community supports. The prevalence of severe obesity is underestimated from self-reported weight and height data. We examined severe obesity prevalence among US adults by sociodemographic characteristics and by state after adjusting for self-report bias. METHODS: Using a validated bias-correction method, we adjusted self-reported body mass index (BMI) data from the 2020 Behavioral Risk Factor Surveillance System (BRFSS) by using measured data from the National Health and Nutrition Examination Survey. We compared bias-corrected prevalence of severe obesity (BMI ≥40) with self-reported estimates by sociodemographic characteristics and state. RESULTS: Self-reported BRFSS data significantly underestimated the prevalence of severe obesity compared with bias-corrected estimates. In 2020, 8.8% of adults had severe obesity based on the bias-corrected estimates, whereas 5.3% of adults had severe obesity based on self-reported data. Women had a significantly higher prevalence of bias-corrected severe obesity (11.1%) than men (6.5%). State-level prevalence of bias-corrected severe obesity ranged from 5.5% (Massachusetts) to 13.2% (West Virginia). Based on bias-corrected estimates, 16 states had a prevalence of severe obesity greater than 10%, a level not seen in the self-reported estimates. CONCLUSION: Self-reported BRFSS data underestimated the overall prevalence of severe obesity by 40% (5.3% vs 8.8%). Accurate state-level estimates of severe obesity can help public health and health care decision makers prioritize and plan to implement effective prevention and treatment strategies for people who are at high risk for poor metabolic health.

Simulation-based estimates and projections of global, regional and country-level maternal mortality by cause, 1990-2050.

Maternal mortality is a major global health challenge. Although progress has been made globally in reducing maternal deaths, measurement remains challenging given the many causes and frequent underreporting of maternal deaths. We developed the Global Maternal Health microsimulation model for women in 200 countries and territories, accounting for individual fertility preferences and clinical histories. Demographic, epidemiologic, clinical and health system data were synthesized from multiple sources, including the medical literature, Civil Registration Vital Statistics systems and Demographic and Health Survey data. We calibrated the model to empirical data from 1990 to 2015 and assessed the predictive accuracy of our model using indicators from 2016 to 2020. We projected maternal health indicators from 1990 to 2050 for each country and estimate that between 1990 and 2020 annual global maternal deaths declined by over 40% from 587,500 (95% uncertainty intervals (UI) 520,600-714,000) to 337,600 (95% UI 307,900-364,100), and are projected to decrease to 327,400 (95% UI 287,800-360,700) in 2030 and 320,200 (95% UI 267,100-374,600) in 2050. The global maternal mortality ratio is projected to decline to 167 (95% UI 142-188) in 2030, with 58 countries above 140, suggesting that on current trends, maternal mortality Sustainable Development Goal targets are unlikely to be met. Building on the development of our structural model, future research can identify context-specific policy interventions that could allow countries to accelerate reductions in maternal deaths.

A simulation-based comparative effectiveness analysis of policies to improve global maternal health outcomes.

The Sustainable Development Goals include a target to reduce the global maternal mortality ratio (MMR) to less than 70 maternal deaths per 100,000 live births by 2030, with no individual country exceeding 140. However, on current trends the goals are unlikely to be met. We used the empirically calibrated Global Maternal Health microsimulation model, which simulates individual women in 200 countries and territories to evaluate the impact of different interventions and strategies from 2022 to 2030. Although individual interventions yielded fairly small reductions in maternal mortality, integrated strategies were more effective. A strategy to simultaneously increase facility births, improve the availability of clinical services and quality of care at facilities, and improve linkages to care would yield a projected global MMR of 72 (95% uncertainty interval (UI) = 58-87) in 2030. A comprehensive strategy adding family planning and community-based interventions would have an even larger impact, with a projected MMR of 58 (95% UI = 46-70). Although integrated strategies consisting of multiple interventions will probably be needed to achieve substantial reductions in maternal mortality, the relative priority of different interventions varies by setting. Our regional and country-level estimates can help guide priority setting in specific contexts to accelerate improvements in maternal health.

Estimating the total incidence of type 1 diabetes in children and adolescents aged 0-19 years from 1990 to 2050: a global simulation-based analysis.

BACKGROUND: Previous studies of type 1 diabetes in childhood and adolescence have found large variations in reported incidence around the world. However, it is unclear whether these reported incidence levels are impacted by differences in country health systems and possible underdiagnosis and if so, to what degree. The aim of this study was to estimate both the total and diagnosed incidence of type 1 diabetes globally and to project childhood type 1 diabetes incidence indicators from 1990 to 2050 for each country. METHODS: We developed the type 1 diabetes global microsimulation model to simulate the natural history and diagnosis of type 1 diabetes for children and adolescents (aged 0-19 years) in 200 countries and territories, accounting for variability in underlying incidence and health system performance. The model follows an open population of children and adolescents in monthly intervals and simulates type 1 diabetes incidence and progression, as well as health system factors which influence diagnosis. We calibrated the model to published data on type 1 diabetes incidence, autoantibody profiles, and proportion of cases diagnosed with diabetic ketoacidosis from 1990 to 2020 and assessed the predictive accuracy using a randomly sampled test set of data withheld from calibration. FINDINGS: We estimate that in 2021 there were 355 900 (95% UI 334 200-377 300) total new cases of type 1 diabetes globally among children and adolescents, of which 56% (200 400 cases, 95% UI 180 600-219 500) were diagnosed. Estimated underdiagnosis varies substantially by region, with over 95% of new cases diagnosed in Australia and New Zealand, western and northern Europe, and North America, but less than 35% of new cases diagnosed in west Africa, south and southeastern Asia, and Melanesia. The total number of incident childhood cases of type 1 diabetes is projected to increase to 476 700 (95% UI 449 500-504 300) in 2050. INTERPRETATION: Our research indicates that the total global incidence of childhood and adolescent type 1 diabetes is larger than previously estimated, with nearly one-in-two children currently undiagnosed. Policymakers should plan for adequate diagnostic and medical capacity to improve timely type 1 diabetes detection and treatment, particularly as incidence is projected to increase worldwide, with highest numbers of new cases in Africa. FUNDING: Novo Nordisk.

Cost-Effectiveness of 5 Public Health Approaches to Prevent Eating Disorders.

INTRODUCTION: Eating disorders cause suffering and a high risk of death. Accelerating the translation of research into implementation will require intervention cost-effectiveness estimates. The objective of this study was to estimate the cost-effectiveness of 5 public health approaches to preventing eating disorders among adolescents and young adults. METHODS: Using data from 2001 to 2017, the authors developed a microsimulation model of a closed cohort starting at the age of 10 years and ending at 40 years. In 2021, an analysis was conducted of 5 primary and secondary prevention strategies for eating disorders: school-based screening, primary care‒based screening, school-based universal prevention, excise tax on over-the-counter diet pills, and restriction on youth purchase of over-the-counter diet pills. The authors estimated the reduction in years lived with eating disorders and the increase in quality-adjusted life-years. Intervention costs and net monetary benefit were estimated using a threshold of $100,000/quality-adjusted life year. RESULTS: All the 5 interventions were estimated to be cost-saving compared with the current practice. Discounted per person cost savings (over the 30-year analytic time horizon) ranged from $63 (clinic screening) to $1,102 (school-based universal prevention). Excluding caregiver costs for binge eating disorder and otherwise specified feeding and eating disorders substantially reduced cost savings (e.g., from $1,102 to $149 for the school-based intervention). CONCLUSIONS: A range of public health strategies to reduce the societal burden of eating disorders are likely cost saving. Universal prevention interventions that promote healthy nutrition, physical activity, and media use behaviors without introducing weight stigma may prevent additional negative health outcomes, such as excess weight gain.

Excess mortality associated with elevated body weight in the USA by state and demographic subgroup: A modelling study.

Background: The obesity epidemic in the USA continues to grow nationwide. Although excess weight-related mortality has been studied in general, less is known about how it varies by demographic subgroup within the USA. In this study we estimated excess mortality associated with elevated body weight nationally and by state and subgroup. Methods: We developed a nationally-representative microsimulation (individual-level) model of US adults between 1999 and 2016, based on risk factor data from 6,002,012 Behavioral Risk Factor Surveillance System respondents. Prior probability distributions for hazard ratios relating body-mass index (BMI) to mortality were informed by a global pooling dataset. Individual-level mortality risks were modelled accounting for demographics, smoking history, and BMI adjusted for self-report bias. We calibrated the model to empirical all-cause mortality rates from CDC WONDER by state and subgroup, and assessed the predictive accuracy of the model using a random sample of data withheld from model fitting. We simulated counterfactual scenarios to estimate excess mortality attributable to different levels of excess weight and smoking history. Findings: We estimated that excess weight was responsible for more than 1300 excess deaths per day (nearly 500,000 per year) and a loss in life expectancy of nearly 2·4 years in 2016, contributing to higher excess mortality than smoking. Relative excess mortality rates were nearly twice as high for women compared to men in 2016 (21·9% vs 13·9%), and were higher for Black non-Hispanic adults. By state, overall excess weight-related life expectancy loss ranged from 1·75 years (95% UI 1·57-1·94) in Colorado to 3·18 years (95% UI 2·86-3·51) in Mississippi. Interpretation: Excess weight has substantial impacts on mortality in the USA, with large disparities by state and subgroup. Premature mortality will likely increase as obesity continues to rise. Funding: The JPB Foundation, NIH, CDC.

The Prevalence of Islet Autoantibodies in Children and Adolescents With Type 1 Diabetes Mellitus: A Global Scoping Review.

Background and Purpose: Pancreatic islet autoantibodies (iAb) are the hallmark of autoimmunity in type 1 diabetes. A more comprehensive understanding of the global iAb prevalence could help reduce avertible morbidity and mortality among children and adolescents and contribute to the understanding in the observed differences in the incidence, prevalence and health outcomes of children and adolescents with type 1 diabetes across and within countries. We present the first scoping review that provides a global synthesis of the prevalence of iAb in children and adolescents with type 1 diabetes. Research Design and Methods: We searched Ovid MEDLINE® with Daily Update, Embase (Elsevier, embase.com) and PubMed (National Library of Medicine -NCBI), for studies pertaining to prevalence in children and adolescents (0-19) with type 1 diabetes published between 1 Jan 1990 and 18 June 2021. Results were synthesized using Covidence systematic review software and meta-analysis was completed using R v3·6·1. Two reviewers independently screened abstracts with a third reviewer resolving conflicts (k= 0·92). Results: The review revealed 125 studies from 48 different countries, with 92 from high-income countries. Globally, in new-onset type 1 diabetes, IA-2A was the most prevalent iAb 0·714 [95% CI (0·71, 0·72)], followed by ICA 0·681 [95% CI (0·67, 0·69)], ZnT8A was 0·654 [95% CI (0·64, 0·66)], GADA 0·636 [95% CI (0·63, 0·66)] and then IAA 0·424 [95% CI (0·42, 0·43)], with substantial variation across world regions. The weighted mean prevalence of IA-2A was more variable, highest in Europe at 0·749 [95% CI (0·74, 0·76)] followed by Northern America 0·662 [95% CI (0·64, 0·69)], Latin America and the Caribbean 0·632 [95% CI (0·54, 0·72)], Oceania 0·603 [95% CI (0·54, 0·67)], Asia 0·466 [95% CI (0·44, 0·50)] and Africa 0·311 [95% CI (0·23, 0·40)]. In established cases of type 1 diabetes, GADA was the most prevalent iAb 0·407 [95% CI (0·39, 0·42)] followed by ZnT8A 0·322 [95% CI (0·29, 0·36)], IA-2A 0·302 [95% CI (0·29, 0·32)], IAA 0·258 [95% CI (0·24, 0·26)] and ICA 0·145 [95% CI (0·13, 0·16)], again with substantial variation across world regions. Conclusion: Understanding the global prevalence of iAb in children and adolescents with type 1 diabetes could help with earlier identification of those at-risk of developing type 1 diabetes and inform clinical practice, health policies, resource allocation, and targeted healthcare interventions to better screen, diagnose and manage children and adolescents with type 1 diabetes.

Incidence and prevalence of type 1 diabetes and diabetic ketoacidosis in children and adolescents (0-19 years) in Thailand (2015-2020): A nationwide population-based study.

BACKGROUND: There is a lack of published studies on incidence of type 1 diabetes (T1D) and diabetic ketoacidosis (DKA) in Thailand. We aimed to estimate the national prevalence and incidence of T1D and DKA. METHODS: Using Thailand's nationwide population-based longitudinal data covering 69 million individuals, we included the entire children and adolescents recorded in the database. Diseases were identified using ICD-10 codes. We investigated the prevalence of T1D and cumulative incidence of T1D, T1D referral, DKA, and mortality risk of DKA in five years from 2015 to 2020. T1D and DKA annual incidence were also estimated. We present findings for the total population and by sex, age, and urban-rural residencies. FINDINGS: A total of 19,784,781 individuals aged less than 20 years were identified in 2015. The crude T1D prevalence in 2015 was 17·6 per 100,000 and crude T1D incidence rate was 5·0 per 100,000. T1D prevalence and cumulative incidence were significantly higher in older children (p < 0·001) and females (p < 0·001) than their counterparts. Among those with T1D, cumulative incidence of T1D referral was 42·4%. It was highest amongst children aged 5-14 years and was significantly higher among females (all p < 0·05). The crude DKA incidence rate at any point after diagnosis was 10·8%. The cumulative incidence of DKA was significantly higher in females and peaked in individuals aged 5-14 years (all p < 0·001). The DKA mortality risk was 258·2 per 100,000. INTERPRETATION: Older children and females had higher T1D prevalence. The DKA cumulative incidence and mortality risk were relatively low, and such incidence was peak in individuals aged 5-14 years. FUNDING: Harvard University.

Variation in the incidence of type 1 diabetes mellitus in children and adolescents by world region and country income group: A scoping review.

INTRODUCTION: Around 18.7 million of the 537 million people with diabetes worldwide live in low-income and middle-income countries (LMIC), where there is also an increase in the number of children, adolescents, and young adults diagnosed with type 1 diabetes (T1D). There are substantial gaps in data in the current understanding of the epidemiological patterns and trends in incidence rates of T1D at the global level. METHODS: We performed a scoping review of published studies that established the incidence of T1D in children, adolescents, and young adults aged 0-25 years at national and sub-national levels using PubMed, Embase and Global Health. Data was analyzed using R programming. RESULTS: The scoping review identified 237 studies which included T1D incidence estimates from 92 countries, revealing substantial variability in the annual incidence of T1D by age, geographic region, and country-income classification. Highest rates were reported in the 5-9 and 10-14 year age groups than in the 0-4 and 15-19 year age groups, respectively. In the 0-14 year age group, the highest incidence was reported in Northern Europe (23.96 per 100,000), Australia/New Zealand (22.8 per 100,000), and Northern America (18.02 per 100,000), while the lowest was observed in Melanesia, Western Africa, and South America (all < 1 per 100,000). For the 0-19 year age group, the highest incidence was reported in Northern Europe (39.0 per 100,000), Northern America (20.07 per 100,000), and Northern Africa (10.1 per 100,000), while the lowest was observed in Eastern and Western Africa (< 2 per 100,000). Higher incidence rates were observed in high-income countries compared to LMICs. There was a paucity of published studies focusing on determining the incidence of T1D in LMICs. CONCLUSION: The review reveals substantial variability in incidence rates of T1D by geographic region, country income group, and age. There is a dearth of information on T1D in LMICs, particularly in sub-Saharan Africa, where incidence remains largely unknown. Investment in population-based registries and longitudinal cohort studies could help improve the current understanding of the epidemiological trends and help inform health policy, resource allocation, and targeted interventions to enhance access to effective, efficient, equitable, and responsive healthcare services.