Systems science for developing policy to improve physical activity, the Caribbean.

The World Health Organization (WHO) Global Action Plan on Physical Activity recommends adopting a systems approach to implementing and tailoring actions according to local contexts. We held group model-building workshops with key stakeholders in the Caribbean region to develop a causal loop diagram to describe the system driving the increasing physical inactivity in the region and envision the most effective ways of intervening in that system to encourage and promote physical activity. We used the causal loop diagram to inform how the WHO Global Action Plan on Physical Activity might be adapted to a local context. Although the WHO recommendations aligned well with our causal loop diagram, the diagram also illustrates the importance of local context in determining how interventions should be coordinated and implemented. Some interventions included creating safe physical activity spaces for both sexes, tackling negative attitudes to physical activity in certain contexts, including in schools and workplaces, and improving infrastructure for active transport. The causal loop diagram may also help understand how policies may be undermined or supported by key actors or where policies should be coordinated. We demonstrate how, in a region with a high level of physical inactivity and low resources, applying systems thinking with relevant stakeholders can help the targeted adaptation of global recommendations to local contexts.

Le Plan d'action mondial pour l'activité physique élaboré par l'Organisation mondiale de la Santé (OMS) recommande d'adopter une approche systémique pour la création et le déploiement d'actions adaptées aux contextes locaux. Nous avons organisé des ateliers de construction de modèles regroupant divers acteurs clés de la région Caraïbes. Objectif: développer un diagramme de boucles causales afin d'identifier le système à l'origine de la sédentarité croissante dans cette région, mais aussi de concevoir les moyens les plus efficaces pour s'immiscer dans ce système en vue d'encourager et de promouvoir l'exercice physique. Nous avons employé le diagramme de boucles causales pour définir comment le Plan d'action mondial pour l'activité physique de l'OMS peut être adapté au contexte local. Bien que les recommandations de l'OMS se rapprochent considérablement de notre diagramme, ce dernier illustre aussi l'importance du contexte local dans la manière dont les interventions sont censées être coordonnées et mises en œuvre. Certaines de ces interventions prévoyaient d'ouvrir des espaces sécurisés dédiés à la pratique sportive pour les deux sexes, de lutter contre les attitudes négatives vis-à-vis de l'activité physique dans des situations spécifiques, notamment à l'école et au travail, et de rendre les infrastructures compatibles avec les modes de transport actifs. Le diagramme de boucles causales permet en outre de mieux comprendre comment les acteurs clés peuvent soutenir ou au contraire discréditer les politiques en la matière, et de voir où ces politiques ont besoin de coordination. Nous démontrons comment, dans une région marquée par un taux de sédentarité élevé et de faibles ressources, l'adoption d'une approche systémique impliquant les principaux intervenants peut contribuer à ajuster avec précision des recommandations mondiales à des contextes locaux.

El Plan de acción mundial sobre actividad física de la Organización Mundial de la Salud (OMS) recomienda adoptar un enfoque sistémico para implementar y adaptar las acciones según los contextos locales. Celebramos talleres de construcción de modelos de grupo con las principales partes interesadas en la región del Caribe para desarrollar un diagrama de circuito causal para describir el sistema que impulsa la creciente inactividad física en la región y prever las formas más eficaces de intervenir en ese sistema para fomentar y promover la actividad física. Utilizamos el diagrama de circuito causal para informar sobre cómo se podría adaptar el Plan de acción mundial sobre actividad física de la OMS a un contexto local. Aunque las recomendaciones de la OMS se ajustaban bien a nuestro diagrama, este también ilustra la importancia del contexto local a la hora de determinar cómo deben coordinarse y aplicarse las intervenciones. Algunas intervenciones incluyen la creación de espacios seguros para la actividad física para ambos sexos, la lucha contra las actitudes negativas hacia la actividad física en determinados contextos, incluidos los colegios y los lugares de trabajo, y la mejora de las infraestructuras para el transporte activo. El diagrama de circuito causal también puede ayudar a entender cómo las políticas pueden ser socavadas o apoyadas por actores clave o dónde deben coordinarse las políticas. Demostramos cómo, en una región con un alto nivel de inactividad física y pocos recursos, la aplicación del pensamiento sistémico con las partes interesadas pertinentes puede ayudar a la adaptación específica de las recomendaciones globales a los contextos locales.

An updated systematic review and meta-analysis on the social determinants of diabetes and related risk factors in the Caribbean.

OBJECTIVES: To conduct an analysis of the most recent data on diabetes and its risk factors by gender and other social determinants of health to understand why its prevalence is higher among women than men in the Caribbean; to inform policy agenda-setting for diabetes prevention and control in the Caribbean; and to identify gaps in the evidence that require further research. METHODS: A previous systematic review of the literature describing studies conducted in the Caribbean that presented the distribution of diabetes, its outcomes, and risk factors, by one or more social determinants, was updated to include sources from 1 January 2007 - 31 December 2016. Surveys by the World Health Organization (WHO) were also included. Where data were sufficient, meta-analyses were undertaken. RESULTS: A total of 8 326 manuscripts were identified. Of those, 282 were selected for full text review, and 114, for abstraction. In all, 36 papers, including WHO-related surveys, had sufficient information for meta-analysis. More women compared to men were obese (OR: 2.1; 95%CI = 1.65 - 2.69), physically inactive (OR: 2.18; 95%CI = 1.75 - 2.72), and had diabetes (OR: 1.48; 95%CI = 1.25 - 1.76). More men smoked (OR: 4.27; 95%CI = 3.18 - 5.74) and had inadequate fruit and vegetable intake (OR: 1.37; 95%CI = 1.21 - 1.57). CONCLUSION: Thirty-six papers were added to the previously conducted systematic review; of those, 13 were added to the meta-analysis. Diabetes and its risk factors (primarily obesity and physical inactivity) continue to disproportionately affect women in the Caribbean. Smoking interventions should be targeted at men in this geographic area.

Upstream Determinants of Overweight and Obesity in Europe.

PURPOSE OF REVIEW: To review the upstream determinants of overweight and obesity in Europe, including food and built environments, and political, commercial, and socioeconomic determinants. RECENT FINDINGS: Overweight and obesity affect 60% of European adults, and one in three children, and are more common in individuals with low compared to high socioeconomic position (SEP). Individuals in low SEP groups are more exposed to unhealthy built and food environments, including higher exposure to unhealthy food marketing. Industries influencing the food system have much economic power, resulting in ignoring or silencing the role of ultra-processed foods and commercial practices in weight gain. Overall, effective policies to address overweight and obesity have been insufficiently implemented by governments. To accelerate implementation, strengthened political commitment is essential. Policies must also focus on the upstream, structural, and systemic drivers of overweight and obesity; be comprehensive; and target socioeconomic inequalities in diets and physical activity.

Understanding the links between human health, ecosystem health, and food systems in Small Island Developing States using stakeholder-informed causal loop diagrams.

Globalized food systems are a major driver of climate change, biodiversity loss, environmental degradation, and the increasing prevalence of overweight and obesity in society. Small Island Developing States (SIDS) are particularly sensitive to the negative effects of rapid environmental change, with many also exhibiting a heavy reliance on food imports and high burdens of nutrition-related disease, resulting in calls to (re)localize their food systems. Such a transition represents a complex challenge, with adaptation interventions in one part of the food system contingent on the success of interventions in other parts. To help address this challenge, we used group model-building techniques from the science of system dynamics to engage food system stakeholders in Caribbean and Pacific SIDS. Our aim was to understand the drivers of unhealthy and unsustainable food systems in SIDS, and the potential role that increased local food production could play in transformative adaptation. We present two causal loop diagrams (CLDs) considered helpful in designing resilience-enhancing interventions in local food systems. These CLDs represent 'dynamic hypotheses' and provide starting points that can be adapted to local contexts for identifying food system factors, understanding the interactions between them, and co-creating and implementing adaptation interventions, particularly in SIDS. The results can help guide understanding of complexity, assist in the co-creation of interventions, and reduce the risk of maladaptive consequences.

Diabetes, HIV and other health determinants associated with absenteeism among formal sector workers in Namibia.

BACKGROUND: As countries in sub-Saharan Africa develop their economies, it is important to understand the health of employees and its impact on productivity and absenteeism. While previous studies have assessed the impact of single conditions on absenteeism, the current study evaluates multiple health factors associated with absenteeism in a large worker population across several sectors in Namibia. METHODS: From March 2009 to June 2010, PharmAccess Namibia conducted a series of cross-sectional surveys of 7,666 employees in 7 sectors of industry in Namibia. These included a self-reported health questionnaire and biomedical screenings for certain infectious diseases and non-communicable disease (NCD) risk factors. Data were collected on demographics, absenteeism over a 90-day period, smoking behavior, alcohol use, hemoglobin, blood pressure, blood glucose, cholesterol, waist circumference, body mass index (BMI), HIV status, and presence of hepatitis B antigens and syphilis antibodies. The associations of these factors to absenteeism were ascertained using negative binomial regression. RESULTS: Controlling for demographic and job-related factors, high blood glucose and diabetes had the largest effect on absenteeism (IRR: 3.67, 95%CI: 2.06-6.55). This was followed by anemia (IRR: 1.59, 95%CI: 1.17-2.18) and being HIV positive (IRR: 1.47; 95%CI: 1.12-1.95). In addition, working in the fishing or services sectors was associated with an increased incidence of sick days (IRR: 1.53, 95%CI: 1.23-1.90; and IRR: 1.70, 95%CI: 1.32-2.20 respectively). The highest prevalence of diabetes was in the services sector (3.6%, 95%CI:-2.5-4.7). The highest prevalence of HIV was found in the fishing sector (14.3%, 95%CI: 10.1-18.5). CONCLUSION: Both NCD risk factors and infectious diseases are associated with increased rates of short-term absenteeism of formal sector employees in Namibia. Programs to manage these conditions could help employers avoid costs associated with absenteeism. These programs could include basic health care insurance including regular wellness screenings.

Exploring ways to respond to rising obesity and diabetes in the Caribbean using a system dynamics model.

Diabetes and obesity present a high and increasing burden of disease in the Caribbean that have failed to respond to prevention policies and interventions. These conditions are the result of a complex system of drivers and determinants that can make it difficult to predict the impact of interventions. In partnership with stakeholders, we developed a system dynamics simulation model to map the system driving diabetes and obesity prevalence in the Caribbean using Jamaica as a test case. The study aims to use the model to assess the magnitude changes necessary in physical activity and dietary intake to achieve global targets set by the WHO Global Action plan and to test scenarios for interventions to reduce the burden of diabetes and obesity. Continuing current trends in diet, physical activity, and demographics, the model predicts diabetes in Jamaican adults (20+ years) to rise from 12% in 2018 to 15.4% in 2030 and 20.9% by 2050. For obesity, it predicts prevalence to rise from 28.6% in 2018 to 32.1% by 2030 and 39.2% by 2050. The magnitude change necessary to achieve the global targets set by the World Health Organization is so great as to be unachievable. However, a combination of measures both upstream (including reducing the consumption of sugar sweetened beverages and ultra processed foods, increasing fruit and vegetable intake, and increasing moderate-to-vigorous activity) at the population level, and downstream (targeting people at high risk and with diabetes) can significantly reduce the future burden of diabetes and obesity in the region. No single intervention reduces the prevalence of these conditions as much as a combination of interventions. Thus, the findings of this model strongly support adopting a sustained and coordinated approach across various sectors to synergistically maximise the benefits of interventions.

IDF diabetes Atlas: Global estimates of undiagnosed diabetes in adults for 2021.

AIMS: To provide up-to-date estimates of undiagnosed diabetes mellitus (UDM) prevalence - both globally, and by region/country, for the year 2021. METHODS: Data sources reporting diabetes prevalence were identified through a systematic search in the peer-reviewed and grey literature. The prevalence of undiagnosed diabetes was estimated from the data from each country where data was available. For countries without in-country data, the prevalence of undiagnosed diabetes was approximated by extrapolating the average of the estimates from countries with data sources within the same International Diabetes Federation (IDF) region and World Bank income grouping. We then applied these stratified prevalence estimates of UDM from each country to the number of adults in each strata and summed the counts to generate the number of adults with UDM (aged 20-79 years) for 215 countries and territories. RESULTS: In 2021, almost one in two adults (20-79 years old) with diabetes were unaware of their diabetes status (44.7%; 239.7 million). The highest proportions of undiagnosed diabetes (53.6%) were found in the Africa, Western Pacific (52.8%) and South-East Asia regions (51.3%), respectively. The lowest proportion of undiagnosed diabetes was observed in North America and the Caribbean (24.2%). CONCLUSIONS: Diabetes surveillance needs to be strengthened to reduce the prevalence of UDM, particularly in low- and middle-income countries.

A Systematic Scoping Review of the Impacts of Community Food Production Initiatives in Kenya, Cameroon, and South Africa.

BACKGROUND: Even before the COVID-19 pandemic, one in two people in Africa were food insecure. The burden of malnutrition remains high (e.g. childhood stunting, anaemia in women of reproductive age) or are increasing (e.g. overweight and obesity). A range of coordinated actions are required to improve this situation, including increasing local food production and consumption. The aim of this review was to provide a systematic and comprehensive overview of recently published research into the health, social, economic, and environmental impacts of community food production initiatives (CFPIs) in Kenya, Cameroon and South Africa. METHODS: We searched eight electronic databases covering health, social, environmental, economic and agricultural sciences. Primary research studies published from 1 January 2014 to 31 December 2018 were considered. Data on geographic location, study design, type of CFPI and the impacts assessed were abstracted from eligible articles. FINDINGS: We identified 4828 articles, 260 of which required full-text review and 118 met our eligibility criteria. Most research was conducted in Kenya (53.4%) and South Africa (38.1%). The categories of CFPIs studied were (in order of decreasing frequency): crop farming, livestock farming, unspecified farming, fisheries, home / school gardens, urban agriculture, and agroforestry. The largest number of studies were on the economic and environmental impacts of CFPIs, followed by their health and social impacts. The health impacts investigated included food security, nutrition status and dietary intake. One study investigated the potential impact of CFPIs on non-communicable diseases. Over 60% of studies investigated a single category of impact. Not one of the studies explicitly used a theoretical framework to guide its design or interpretation. CONCLUSIONS: Our findings on research studies of CFPIs suggest the need for a greater focus on interdisciplinary research in order to improve understanding of the relationships between their health, environmental, economic, and social impacts. Greater use of explicit theoretical frameworks could assist in research design and interpretation, helping to ensure its relevance to informing coordinated intersectoral interventions and policy initiatives.

Using Group Model Building to Describe the System Driving Unhealthy Eating and Identify Intervention Points: A Participatory, Stakeholder Engagement Approach in the Caribbean.

Many Small Island Developing States of the Caribbean experience a triple burden of malnutrition with high rates of obesity, undernutrition in children, and iron deficiency anemia in women of reproductive age, driven by an inadequate, unhealthy diet. This study aimed to map the complex dynamic systems driving unhealthy eating and to identify potential points for intervention in three dissimilar countries. Stakeholders from across the food system in Jamaica (n = 16), St. Kitts and Nevis (n = 19), and St. Vincent and the Grenadines (n = 6) engaged with researchers in two group model building (GMB) workshops in 2018. Participants described and mapped the system driving unhealthy eating, identified points of intervention, and created a prioritized list of intervention strategies. Stakeholders were also interviewed before and after the workshops to provide their perspectives on the utility of this approach. Stakeholders described similar underlying systems driving unhealthy eating across the three countries, with a series of dominant feedback loops identified at multiple levels. Participants emphasized the importance of the relative availability and price of unhealthy foods, shifting cultural norms on eating, and aggressive advertising from the food industry as dominant drivers. They saw opportunities for governments to better regulate advertising, disincentivize unhealthy food options, and bolster the local agricultural sector to promote food sovereignty. They also identified the need for better coordinated policy making across multiple sectors at national and regional levels to deliver more integrated approaches to improving nutrition. GMB proved to be an effective tool for engaging a highly diverse group of stakeholders in better collective understanding of a complex problem and potential interventions.

Global and regional diabetes prevalence estimates for 2019 and projections for 2030 and 2045: Results from the International Diabetes Federation Diabetes Atlas, 9th edition.

AIMS: To provide global estimates of diabetes prevalence for 2019 and projections for 2030 and 2045. METHODS: A total of 255 high-quality data sources, published between 1990 and 2018 and representing 138 countries were identified. For countries without high quality in-country data, estimates were extrapolated from similar countries matched by economy, ethnicity, geography and language. Logistic regression was used to generate smoothed age-specific diabetes prevalence estimates (including previously undiagnosed diabetes) in adults aged 20-79 years. RESULTS: The global diabetes prevalence in 2019 is estimated to be 9.3% (463 million people), rising to 10.2% (578 million) by 2030 and 10.9% (700 million) by 2045. The prevalence is higher in urban (10.8%) than rural (7.2%) areas, and in high-income (10.4%) than low-income countries (4.0%). One in two (50.1%) people living with diabetes do not know that they have diabetes. The global prevalence of impaired glucose tolerance is estimated to be 7.5% (374 million) in 2019 and projected to reach 8.0% (454 million) by 2030 and 8.6% (548 million) by 2045. CONCLUSIONS: Just under half a billion people are living with diabetes worldwide and the number is projected to increase by 25% in 2030 and 51% in 2045.

IDF Diabetes Atlas estimates of 2014 global health expenditures on diabetes.

AIMS: To estimate health expenditures due to diabetes in 2014 for the world and its regions. METHODS: Diabetes-attributable health expenditures were estimated using an attributable fraction method. Data were sourced from International Diabetes Federation (IDF) estimates of diabetes prevalence, UN population projections, WHO annual health expenditure reports, and estimates of the cost ratio of people with and without diabetes. Health expenditures were calculated in both US dollars (USD) and international dollars (ID). RESULTS: The average health expenditure per person with diabetes worldwide in 2014 was estimated to range from USD 1583 (ID 1742) to USD 2842 (ID 3110). The estimated annual global health expenditure attributable to diabetes ranged from USD 612 billion (ID 673 billion) to USD 1099 billion (ID 1202 billion). Together, the North America and Caribbean Region and the Europe Region were responsible for over 69% of the costs, and less than 10% of the costs were from the Africa Region, South East Asia Region, and Middle East and North Africa Region combined. The North America and Caribbean Region had the highest annual spending per person with diabetes (USD 7984 [ID 8040.39]), while the South East Asia Region had the lowest annual spending per person with diabetes (USD 92 [ID 234]). CONCLUSIONS: Diabetes imposes a large economic burden on health care systems across the world, yet varies across world regions. Diabetes prevention and effective management of diabetes should be a public health priority to reduce the financial burden.

Prevalence and Knowledge Assessment of HIV and Non-Communicable Disease Risk Factors among Formal Sector Employees in Namibia.

INTRODUCTION: The burden of non-communicable diseases (NCDs) is growing in sub-Saharan Africa combined with an already high prevalence of infectious disease, like HIV. Engaging the formal employment sector may present a viable strategy for addressing both HIV and NCDs in people of working age. This study assesses the presence of three of the most significant threats to health in Namibia among employees in the formal sector: elevated blood pressure, elevated blood glucose, and HIV and assesses the knowledge and self-perceived risk of employees for these conditions. METHODS: A health and wellness screening survey of employees working in 13 industries in the formal sector of Namibia was conducted including 11,192 participants in the Bophelo! Project in Namibia, from January 2009 to October 2010. The survey combined a medical screening for HIV, blood glucose and blood pressure with an employee-completed survey on knowledge and risk behaviors for those conditions. We estimated the prevalence of the three conditions and compared to self-reported employee knowledge and risk behaviors and possible determinants. RESULTS: 25.8% of participants had elevated blood pressure, 8.3% of participants had an elevated random blood glucose measurement, and 8.9% of participants tested positive for HIV. Most participants were not smokers (80%), reported not drinking alcohol regularly (81.2%), and had regular condom use (66%). Most participants could not correctly identify risk factors for hypertension (57.2%), diabetes (57.3%), or high-risk behaviors for HIV infection (59.5%). In multivariate analysis, having insurance (OR:1.15, 95%CI: 1.03 - 1.28) and a managerial position (OR: 1.29, 95%CI: 1.13 - 1.47) were associated with better odds of knowledge of diabetes. CONCLUSION: The prevalence of elevated blood pressure, elevated blood glucose, and HIV among employees of the Namibian formal sector is high, while risk awareness is low. Attention must be paid to improving the knowledge of health-related risk factors as well as providing care to those with chronic conditions in the formal sector through programs such as workplace wellness.

Global estimates of undiagnosed diabetes in adults.

AIMS: The prevalence of diabetes is rapidly increasing worldwide. Type 2 diabetes may remain undetected for many years, leading to severe complications and healthcare costs. This paper provides estimates of the prevalence of undiagnosed diabetes mellitus (UDM), using available data from high quality representative population-based sources. METHODS: Data sources reporting both diagnosed and previously undiagnosed diabetes were identified and selected according to previously described IDF methodology for diabetes in adults (aged 20-79). Countries were divided into 15 data regions based on their geographic IDF Region and World Bank income classification. The median UDM proportion was calculated from selected data sources for each of data region. The number of UDM cases in 2013 was calculated from country, age and sex-specific estimates of known diabetes cases and data region-specific UDM proportion. RESULTS: Of 744 reviewed data sources, 88 sources representing 74 countries had sufficient information and were selected for generation of estimates of UDM. Globally, 45.8%, or 174.8 million of all diabetes cases in adults are estimated to be undiagnosed, ranging from 24.1% to 75.1% across data regions. An estimated 83.8% of all cases of UDM are in low- and middle-income countries. At a country level, Pacific Island nations have the highest prevalence of UDM. CONCLUSIONS: There is a high proportion of UDM globally, and especially in developing countries. Further high-quality studies of UDM are needed to strengthen future estimates.

Diabetes in the young - a global view and worldwide estimates of numbers of children with type 1 diabetes.

This paper describes the methodology, results and limitations of the 2013 International Diabetes Federation (IDF) Atlas (6th edition) estimates of the worldwide numbers of prevalent cases of type 1 diabetes in children (<15 years). The majority of relevant information in the published literature is in the form of incidence rates derived from registers of newly diagnosed cases. Studies were graded on quality criteria and, if no information was available in the published literature, extrapolation was used to assign a country the rate from an adjacent country with similar characteristics. Prevalence rates were then derived from these incidence rates and applied to United Nations 2012 Revision population estimates for 2013 for each country to obtain estimates of the number of prevalent cases. Data availability was highest for the countries in Europe (76%) and lowest for the countries in sub-Saharan Africa (8%). The prevalence estimates indicate that there are almost 500,000 children aged under 15 years with type 1 diabetes worldwide, the largest numbers being in Europe (129,000) and North America (108,700). Countries with the highest estimated numbers of new cases annually were the United States (13,000), India (10,900) and Brazil (5000). Compared with the prevalence estimates made in previous editions of the IDF Diabetes Atlas, the numbers have increased in most of the IDF Regions, often reflecting the incidence rate increases that have been well-documented in many countries. Monogenic diabetes is increasingly being recognised among those with clinical features of type 1 or type 2 diabetes as genetic studies become available, but population-based data on incidence and prevalence show wide variation due to lack of standardisation in the studies. Similarly, studies on type 2 diabetes in childhood suggest increased incidence and prevalence in many countries, especially in Indigenous peoples and ethnic minorities, but detailed population-based studies remain limited.

IDF diabetes atlas: global estimates of the prevalence of diabetes for 2011 and 2030.

INTRODUCTION: Diabetes is an increasingly important condition globally and robust estimates of its prevalence are required for allocating resources. METHODS: Data sources from 1980 to April 2011 were sought and characterised. The Analytic Hierarchy Process (AHP) was used to select the most appropriate study or studies for each country, and estimates for countries without data were modelled. A logistic regression model was used to generate smoothed age-specific estimates which were applied to UN population estimates for 2011. RESULTS: A total of 565 data sources were reviewed, of which 170 sources from 110 countries were selected. In 2011 there are 366 million people with diabetes, and this is expected to rise to 552 million by 2030. Most people with diabetes live in low- and middle-income countries, and these countries will also see the greatest increase over the next 19 years. DISCUSSION: This paper builds on previous IDF estimates and shows that the global diabetes epidemic continues to grow. Recent studies show that previous estimates have been very conservative. The new IDF estimates use a simple and transparent approach and are consistent with recent estimates from the Global Burden of Disease study. IDF estimates will be updated annually.

The International Diabetes Federation diabetes atlas methodology for estimating global and national prevalence of diabetes in adults.

INTRODUCTION: Diabetes is a major cause of morbidity and mortality and its global prevalence is growing rapidly. A simple and robust approach to estimate the prevalence of diabetes is essential for governments to set priorities on how to meet the challenges of the disease. The International Diabetes Federation has developed a methodology for generating country-level estimates of diabetes prevalence in adults (20-79 years). METHODS: Using country-level data sources from peer-reviewed studies, national health statistics reports, commissioned studies on diabetes prevalence, and unpublished data obtained through personal communication, we use logistic regression to generate estimates of the prevalence of diabetes. An approach matching countries on ethnicity, geography, and income group is used to fill in gaps where original data sources are not available. The methodology also uses changes in urbanization and population to generate estimates and projections on the prevalence of diabetes in adults. CONCLUSION: Diabetes prevalence estimates are very sensitive to the data from which they are derived. The revised IDF methodology for estimating diabetes prevalence is a transparent, reproducible approach that will be updated annually. It takes data-driven approaches to filling in gaps where data are not available and where assumptions have to be made. It uses a qualification system to rank data sources so that only the highest quality data are used.