Part Two. The urgent need for action
Chapter One. Chronic diseases: causes and health impact
Burden of disease
As well as a high death toll, chronic diseases also cause disability, often for decades of a person’s life. The most widely used summary measure of the burden of disease is the disability adjusted life year (or DALY), which combines the number of years of healthy life lost to premature death with time spent in less than full health. One DALY can be thought of as one lost healthy year of life. The projected global burden of disease for all ages, as measured by DALYs, is shown in the figure on the right, along with the burden of the leading chronic diseases. Approximately half of the burden of disease will be caused by chronic diseases, 13% by injuries and 39% by communicable diseases, maternal and perinatal conditions, and nutritional deficiencies combined. Cardiovascular diseases are the leading contributor, among the chronic diseases, to the global burden of disease.
The estimated burden of chronic diseases in men and women and for the four age groups is shown in the table on the next page. The number of DALYs caused by chronic disease is greatest in adults aged 30–59 years, and the rates increase with age. Overall, the burden of disease rates are similar in men and women. Approximately 86% of the burden of chronic disease occurs in people under the age of 70 years.