a global burden

The Challenge | The Response | The Opportunities for U.S. Engagement

The Health Challenge

Rates of non-communicable or chronic disease continue to increase dramatically in all countries (industrialized, middle income, low income), surpassing infections as a disease burden among adults. Many countries do not have the financial or human resources to effectively identify, manage or prevent either these diseases or the individual and social risk factors that are their underlying causes. Yet, most donors are not yet sufficiently focused on the large and growing burden of these diseases in developing countries.

Disease Burden

Chronic disease rates have been rising in all countries. In 2002, the most recent year for which complete data are available, 60% of the 56 million deaths worldwide were due at least in part to chronic diseases. Nearly ¾ of the world’s chronic disease-related deaths that year occurred in developing countries.

Globally, the leading chronic disease problems are: cardiovascular diseases (including strokes), cancer, chronic lung disease (including asthma), and diabetes.

WHO, Preventing Chronic Disease : A Vital Investment. 2009

These problems are often the result of behaviors that increase disease risk, such as smoking tobacco, alcohol use, unhealthy diet and physical inactivity. These latter risk factors give rise to intermediate conditions such as obesity, high blood pressure and abnormal lipid (cholesterol) and glucose metabolism.

The major economic impacts of chronic diseases include higher health care costs, lost productivity due to illness, disability and death among the working age population, and the need to replace these lost workers. For example, a recent study estimated that 22.6% of China’s total health care expenditures in 1995 went for care of diet-related chronic diseases such as coronary heart disease, hypertension, stroke, cancer and diabetes. The estimated productivity cost of these diseases was 0.5% of gross domestic product.

• Cardiovascular diseases - While rates of cardiovascular disease (CVD), including coronary heart disease (CHD) and stroke, have been declining in most industrialized countries, including the United States and the U.K., they are rising in most developing countries. For example, stroke mortality rates in Tanzania are three-fold higher than in the U.K. Based on available trend data, rates of CHD mortality were projected “to increase in developing countries between 1990 and 2020 by 120% for women and 137% for men, compared with age-related increases of between 30% and 60% respectively in industrialized countries.” People with CVD in developing countries develop symptoms and die at younger ages than in industrialized countries. Coronary artery disease among middle-aged men and women in Pakistan, for example, was reported as an astounding 26.9% and 30% respectively. CVD death rates among working women in India and South Africa are higher now than CVD rates among American women in the 1950s.
• Diabetes - By 2030, the 2000 global estimate of 171 million people with diabetes is projected to increase to 366 million, more than 80% of whom will live in developing countries. This number of diabetics will represent more than 6% of the world’s population. These are likely to be conservative numbers since they were estimated without taking into account currently increasing rates of obesity in developing countries, which will lead to larger numbers of people with Type 2 (“adult onset”) diabetes. Even the poorest countries are seeing striking increases in diabetes prevalence; at least 10% of urban Tanzanian adults over 35 years of age are estimated to be diabetic.
• Cancer - Cancer incidence increased globally between 1990 and 2000 and is projected to increase further by 50%, to more than 15 million new cancer patients by 2025. Some of the rise is due to global population change and to gradual aging. However, most of the increase is thought to be due to increasing tobacco use, chronic infections (e.g., hepatitis B, hepatitis C and human papilloma virus) poor diet and physical inactivity.
• Chronic respiratory diseases - Most illness and death in this category is due to chronic obstructive pulmonary disease (COPD). Major COPD risk factors include tobacco, childhood pneumonia, various occupational exposures, and air pollution from unventilated indoor cooking and heating. These risk factors are far more prevalent in developing countries.
• Co-Morbidity - This term refers to simultaneous occurrence of two or more diseases. Examples of chronic disease co-morbidities include: (1) the association between COPD and cancer (both of which are linked to tobacco use) and (2) the association between cardiovascular disease and diabetes, since coronary artery disease and heart attacks occur much more frequently among diabetics than among non-diabetics of the same age and gender groups.

World Health Organization, World Health Statistics 2008, Geneva: 2008.

The Response

Determinants of Chronic Diseases

Population aging, urbanization, economic development and “globalization” of consumer markets each help drive increases in major chronic diseases. Population aging allows more people to live to the age when these diseases become manifest. The other factors operate through increased exposure to tobacco, foods high in fat and salt and physical inactivity.

Options for Preventing and Managing Chronic Diseases

There are three key linked interventions for this group of chronic diseases:

• A sustained public health promotion campaign supported by high level political leadership.
• Focused prevention programs aimed at reducing the prevalence of specific risk factors such as smoking and unhealthy diet.
• Clinically-focused health sector programs to identify (1) individuals with multiple risk factors who are not yet clinically ill but who could benefit from early intervention, and (2) individuals with early signs of chronic disease who could benefit from interventions to prevent or delay the onset of complications.

Other Chronic Diseases

Beyond the major diseases discussed above, several other conditions are responsible for large amounts of preventable disease and/or disability. For examples, neuro-psychiatric diseases such as untreated epilepsy, untreated schizophrenia, alcohol abuse and major depression account for a large proportion of the global disease burden.

In the 2000 Global Burden of Disease Study, major depression, alcohol abuse and self-inflicted injuries were each among the 20 leading causes of the global disease burden; 12.3% of the total global disease burden was due to mental disorders. Diseases of under-nutrition are also common, serious, preventable and largely treatable.

Opportunities for U.S. Engagement

• The U.S. government could consider assisting the governments of developing countries to increase the quantity and quality of information available on their own chronic disease burdens and chronic disease risk factors and to consider options for appropriate intervention(s). In the near term, this goal might be accomplished by supporting the provision of short- and medium term technical assistance in chronic disease epidemiology and in health promotion, either provided from U.S. organizations such as CDC, or from U.S. universities with appropriate chronic disease expertise. Over the longer term, the U.S government could support the training and development of sustainable expertise in other countries through programs such as those of NIH’s Fogarty Center (NIH) or CDC’s Field Epidemiology Training Program.