What is the IDF Diabetes Atlas?
The IDF Diabetes Atlas is the authoritative resource on the global impact of diabetes. First published in 2000, it is produced by the International Diabetes Federation (IDF) in collaboration with a committee of scientific experts from around the world and contains statistics on diabetes prevalence, diabetes-related mortality and health expenditure at the global, regional and national level. The 9th edition has been produced thanks to educational grants (2018-2019) from Pfizer-MSD Alliance, with the additional support of Lilly Diabetes and Novo Nordisk.
What is new in the IDF Diabetes Atlas 9th edition?
The following modifications have been made in the IDF Diabetes Atlas 9th edition:
- A more extended collection of data on the prevalence of diabetes in languages other than English (i.e. Arabic, Chinese, Danish, French, German, Portuguese, Russian, Spanish)
- The troubling emergence of type 2 diabetes in children and young people has been discussed (Chapter 1) and a greater emphasis has been given to acute complications associated with childhood diabetes (Chapter 5).
- Estimates of the incidence of diabetes in both children and adolescents, and adults are included (Chapter 3).
- Projections of hyperglycaemia in pregnancy for the years 2030 and 2045 are included (Chapter 3).
- Indirect costs of diabetes are included (Chapter 3).
- Access to insulin, and the implications of universal health coverage (UHC) are discussed (Chapter 6).
- Diabetes and cancer, is the subject of a new section (Chapter 5).
- The feasibility of type 2 diabetes prevention is given more prominence (Chapter 6) and the aspiration to prevent or delay the type 1 diabetes process is also declared in the same chapter.
- An Advocacy Guide has been developed, with key statistics and arguments to serve as a toolkit for diabetes advocates.
Where does IDF get its information from for the Diabetes Atlas estimates?
The data used in the 9th edition of the IDF Diabetes Atlas comes from a variety of sources such as peer-reviewed scientific papers, Ministry of Health websites, and national and regional health surveys. Official reports by international organisations, such as the World Health Organization (WHO), were also assessed for their quality that was defined in consensus with an international expert panel. Data sources that passed strict selection criteria were included in the data analysis.
What is the confidence interval?
Confidence intervals have been produced to quantify the uncertainty around diabetes prevalence estimates. Uncertainty estimates were produced to estimate the impact of the various analytical decisions on the final prevalence estimates. These intervals thus reflect the uncertainty levels around the diabetes prevalence estimates.
What factors IDF have taken into account when calculating the Atlas projections for the years 2030 and 2045?
The 2030 and 2045 prevalence projections do not include projected changes in any diabetes risk factors (e.g. body weight) and only takes into account changes in age and urbanisation. As a result, projections are quite conservative with wide confidence interval range.
Are undiagnosed people with diabetes included in the total number of people with diabetes?
Undiagnosed people with diabetes are included in the total number of people with diabetes estimated for 2019, 2030 and 2045.
What is the difference between incidence and prevalence?
Incidence is the number of new cases of a disease or condition among a defined group of people during a specified time period. For example, the number of new cases of type 1 diabetes in children and adolescents living in a given country in one year.
Prevalence is the proportion or number of individuals in a population that already has a disease or condition at a particular time (a point in time or over a period of time).
What is the difference between prevalence and age-adjusted comparative prevalence in the IDF Diabetes Atlas?
National or regional prevalence is the actual percentage of the adult population (20-79 years) in a country or Region that has diabetes. It is calculated by taking the estimated number of cases in adults and dividing by the total population in adults. The national prevalence should be used when reporting statistics for just one country or region, or when the statistics being reported are not for comparison.
Age-adjusted comparative prevalence is more appropriate for comparing countries with each other or Regions with each other. Age-adjusted comparative prevalence is calculated by assuming that a country or Region has an age structure identical to that of the world's population. As the prevalence of diabetes increases with age, raw prevalence estimates cannot be used for comparing the prevalence of diabetes between countries that have different age structures, such as, for example, Japan and India. In order to make such comparisons between countries, age-adjusted comparative estimates should be used. Age-adjusted comparative diabetes prevalence was then produced by standardising each country's prevalence to the 2001 WHO standard population. The 2001 WHO standard population has been calculated for the period 2000-2025 and therefore valid to be used for 2019 age-adjusted comparative estimates.
The prevalence estimates for a particular country or Region have changed compared to the previous editions of the Atlas. Why?
Although it might be tempting to focus solely on the figures for a given country or IDF Region, other factors need be taken into account when interpreting the IDF Diabetes Atlas estimates and any differences from those given in the previous edition. Possible reasons for significant differences are:
- The inclusion of new studies for some countries without in-country data sources in the previous edition.
- In the case of extrapolated prevalence estimates for countries without in-country data, the inclusion of new studies for those countries used for the extrapolations.
- Changes in study selection from the previous edition as a result of an updated analytical hierarchy process (AHP) scoring.
- The exclusion of specific WHO STEPS surveys included in the previous edition, as a result of emerging concerns about their validity
Detailed IDF Diabetes Atlas methods and the full list of data sources used to estimate diabetes prevalence in each country can be found at: www.diabetesatlas.org.
What are the main factors driving the increase in diabetes prevalence?
Increasing prevalence of type 2 diabetes is associated with higher levels of urbanisation, ageing populations and unhealthy lifestyles including insufficient physical activity and a higher consumption of unhealthy foods. The causes of the increased incidence of type 1 diabetes are not yet clear.
What should we be concerned about?
Diabetes-related health expenditure is now estimated to account for 10% of the total global healthcare budget. As 700 million people are projected to have diabetes in 2045, it is essential that more efforts are made to implement type 2 diabetes prevention plans and to introduce more cost-effective ways to manage type 1, type 2, and gestational diabetes.
Why does Europe have the highest number of children with type 1 diabetes?
The data on the incidence and prevalence of children with type 1 diabetes is scarce, and mostly collected in high income countries, which may have an impact on the final numbers. In populations of European origin, nearly all children and adolescents with diabetes have type 1 diabetes, but in other populations (e.g. Japan), type 2 diabetes is more common than type 1 diabetes in this age group. In countries with limited access to insulin and inadequate health service provision, children and adolescents with type 1 diabetes, even when correctly diagnosed, face serious complications and consequently premature mortality. The risk factors for type 1 diabetes are also not clear, but have been linked to infections and other environmental factors.
Why does the Western Pacific have the highest number of people with diabetes?
Among all the IDF Regions, Western Pacific has the highest adult population aged 20-79 years old (1.7 billion). This could one of the reasons for the large number of adults with diabetes in the Region (163 million).
How can we improve diagnosis rates?
Globally, half of all people with diabetes are undiagnosed. We can improve the rate of diagnosis by increasing awareness of the symptoms of type 1 diabetes (thirst, increased urination, tiredness, sudden weight loss, hunger), and increasing screening opportunities for people at high risk of type 2 diabetes (older age, overweight and obesity, complications, low level of physical activity, and unhealthy diet).
What is the impact of hyperglycaemia in pregnancy? What does this mean to the health of future generation?
Globally, one in six births (16 %) is affected by hyperglycaemia in pregnancy. The risk of gestational diabetes increases with age. Gestational diabetes is associated with complications during delivery in both the mother and child, so it not only affects immediate maternal and neonatal outcomes but it also increases the risk of future type 2 diabetes in both the mother and the baby.