Chronic conditions such as cancer, cardiovascular conditions, chronic respiratory problems and diabetes are not only the leading causes of death across OECD countries but also represent a major disability burden. Many chronic conditions are preventable, by modifying major risk factors such as smoking, harmful alcohol use, obesity and physical inactivity (see Chapter 4 “Non-medical determinants and risk factors”). Chronic conditions that are linked to risk factors – such as type 2 diabetes, heart failure and chronic kidney disease – share a common development pathway and often occur simultaneously, generating multimorbidity.
More than one‑third of people aged 16 and over reported living with a long-standing illness or health problem on average across 29 OECD countries in 2021 (Figure 3.16). This figure ranges from more than one in two in Finland to just under one in five in Italy. As populations age, the prevalence of chronic conditions – including multimorbidity – rises. Health systems increasingly need to be prepared to deliver high-quality chronic care management to meet the needs of ageing populations.
Socio‑economic disparities are also large: on average across OECD countries, people in the lowest income quintile are 15 percentage points (p.p.) more likely to report having a long-standing chronic condition (44%) compared to people in the highest income quintile (28%). While this disparity is observed across all OECD countries, the income gap is largest in Lithuania, Latvia, Belgium, Ireland and Czechia, where people in the lowest income quintile are more than twice as likely to have at least one long-standing illness or health problem compared to people in the highest income quintile. The income gap is smallest in the Slovak Republic and Spain, where individuals in the lowest income quintile are only 5 p.p. more likely to report living with a long-standing illness or health problem compared to individuals in the highest income quintile.
One of the most significant chronic conditions is diabetes. It has a particularly large disability burden, as it can cause cardiovascular disease, blindness, kidney failure and lower limb amputation (OECD, forthcoming[1]). The economic burden of diabetes is substantial: in OECD countries, an estimated USD 670 billion was spent on treating diabetes and preventing complications in 2021 (IDF, 2025[2]). In 2022, an estimated 8.6% of the adult population was living with diabetes on average across OECD countries (age‑standardised data). Among OECD countries, diabetes prevalence was highest in Costa Rica, Türkiye, Mexico and Chile, Mexico with 14.0% of adults or more living with diabetes (age‑standardised data). For OECD accession/partner countries, diabetes prevalence is also relatively high in India and Peru (Figure 3.17).
Age‑standardised diabetes prevalence rates have increased in most OECD Member countries over the last decade. Exceptions are Denmark, France, Spain, Germany, Israel and Mexico. The highest increase was seen in Costa Rica, with a 6.7 p.p. increase. Large increases were also seen in accession countries Indonesia and Peru. Such upward trends are due in part to rising rates of obesity, poor nutrition and physical inactivity, as well as to their interactions with population ageing.
Living with multiple chronic conditions increases the burden on patients and on healthcare systems. Data from the OECD Patient-Reported Indicator Surveys (PaRIS) shows that 82% of primary care users aged 45 and over reported having at least one chronic condition, and 52% two or more (Figure 3.18). Among the countries participating in PaRIS, Slovenia and Greece reported the smallest proportion of primary care users with two or more chronic conditions; the highest shares were observed in the United States and Australia. As populations age, so does the prevalence of multiple chronic conditions. This calls for more co‑ordinated care for people managing multiple conditions and for better collaboration between patients and healthcare professionals such as family doctors, pharmacists, nurses and other specialists (OECD, 2025[3]).
