Frequently asked questions

The following modifications have been made in the IDF Diabetes Atlas 10th edition:

• Impaired fasting glucose is included for the first time
• Diabetes and Covid-19 is a new emerging topic
• Types of diabetes in different populations are presented, including the emergence of type 2 diabetes in children and adolescents and type 1 diabetes in adults
• Estimates of the incidence of type 2 diabetes are included concerning adult populations

The data in the IDF Diabetes Atlas 10th  edition come from a variety of sources such as peer-reviewed scientific papers, 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.

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 therefore reflect the uncertainty levels around the diabetes prevalence estimates.

The prevalence projections for 2030 and 2045 only take into account changes in age and urbanisation. They do not factor in projected changes in any diabetes risk factors (e.g. body weight). As a result, the projections are quite conservative with a wide confidence interval range.

Yes, people with undiagnosed diabetes are included in the total estimated number of people with diabetes for 2021, 2030 and 2045.

Detailed estimates for the 215 countries and territories covered in the IDF Diabetes Atlas 10th Edition can be found at https://diabetesatlas.org/data/en/. The full content of the IDF Diabetes Atlas 10th Edition is available at https://diabetesatlas.org/atlas/tenth-edition/. All enquiries related to the data and information included in the IDF Diabetes Atlas 10th Edition can be addressed to atlas@idf.org.

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).

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, also referred to as comparative prevalence, is the prevalence calculated by adjusting to the age structure of a standard population. In the IDF Diabetes Atlas 10th Edition, the standard population is the UN population for 2021, 2030 or 2045.  Adjusting rates is a way to make fairer comparisons between groups with different distributions. Age-adjusted rates are rates that would have existed if the population under study had the same age distribution as the “standard” population.

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 used for the extrapolations or a change in extrapolation grouping.
• 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 [Plese provide link].

The increasing prevalence of type 2 diabetes is associated with higher levels of urbanisation, ageing populations and unhealthy habits, including insufficient physical activity and higher consumption of unhealthy foods. The causes of the increased incidence of type 1 diabetes are not yet clear.

Diabetes-related health expenditure is now estimated to account for 11.5% of the total global healthcare budget. As 784 million people (1 in 8) are projected to have diabetes by 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 the different types of diabetes.

The IDF Western Pacific region has the highest adult population aged 20-79 years old (1.7 billion). This could one of the reasons that explain why the region has the highest number of adults with diabetes (206 million) of all IDF regions.

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, 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.

Globally, almost half of all people with diabetes are undiagnosed. Diagnosis rates can be improved by increasing awareness of the symptoms of type 1 diabetes (excessive thirst, increased urination, lack of energy, sudden weight loss, hunger), and increasing screening opportunities for people at high risk of type 2 diabetes (older age, overweight and obesity, family history, low level of physical activity and unhealthy diet).

Globally, one in six births (21 million) is affected by hyperglycaemia in pregnancy. The risk of gestational diabetes increases with age. Gestational diabetes is associated with complications during delivery in both mother and child. It therefore not only affects immediate maternal and neonatal outcomes, but also increases the risk of future development of type 2 diabetes in both mother and child.