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Years of healthy life can be increased 5-10 years, WHO says

Cover of 2002 World Health Report

Worldwide, healthy life expectancy can be increased by 5-10 years if governments and individuals make combined efforts against the major health risks in each region, the World Health Organization (WHO) says in its new yearly report.

The World Health Report 2002 -- Reducing Risks, Promoting Healthy Life - breaks new ground by identifying some major principal global risks to disease, disability and death in the world today, quantifying their actual impact from region to region, and then providing examples of cost-effective ways to reduce those risks, applicable even in poor countries.

“This report provides a road map for how societies can tackle a wide range of preventable conditions that are killing millions of people prematurely and robbing tens of millions of healthy life,” says WHO Director-General Gro Harlem Brundtland, MD. “WHO will take this report and focus on the interventions that would work best in each region and on getting the information out to Member States.”

From more than 25 major preventable risks selected for in-depth study, the report finds that the top 10 globally are: childhood and maternal underweight; unsafe sex; high blood pressure; tobacco; alcohol; unsafe water, sanitation and hygiene; high cholesterol; indoor smoke from solid fuels; iron deficiency and overweight/obesity. Together, they account for about 40 per cent of the 56 million deaths that occur worldwide annually and one-third of global loss of healthy life years.

These leading risks are comparatively much more important than widely believed. WHO calls the contrast between rich and poor people “shocking.” The burden from many of the risks is borne almost exclusively by the developing world, while other risks have already become global. Some 170 million children in poor countries are underweight, mainly from lack of food, while more than one billion adults worldwide – in middle income and high income countries alike are overweight or obese. About half a million people in North America and Western Europe die from overweight/obesity-related diseases every year.

WHO warns that the “cost of inaction is serious.” The report predicts that unless action is taken, by the year 2020 there will be nine million deaths caused by tobacco, compared to almost five million a year now; five million deaths attributable to overweight and obesity, compared to three million now; that the number of healthy life years lost by underweight children will be 110 million, which, although lower than 130 million now, is still unacceptably high.

If all of these preventable risks could be addressed as WHO recommends (which WHO acknowledges is a highly ambitious goal), healthy life spans could increase as much as 16 plus years in parts of Africa, where healthy life expectancy now falls as low as just 37 years (in Malawi). Even in the richer developing countries, such as Europe, the United States, Australia, New Zealand and Japan, healthy life spans would increase by about five years.

“Globally, we need to achieve a much better balance between preventing disease and merely treating its consequences,” says Christopher Murray, M.D., Ph.D., Executive Director of WHO's Global Programme on Evidence for Health Policy and overall director of World Health Report 2002. “This can only come about with concerted action to identify and reduce major risks to health.”

WHO has developed a unique framework for using a wide body of scientific evidence to comparably assess the impact of different risks in a ‘common currency’ of lost healthy life years, called the DALY (disability-adjusted life year). This takes into account the impact of the different risks on mortality and on morbidity. A DALY is equal to the loss of one healthy year of life.

Risks that result in death reduce life expectancy. Risks that result in short or long term morbidity mean that people stay alive, but not in full health. Healthy life expectancy (HALE) is, therefore, lower than life expectancy. For example, overall life expectancy in Japan is 84.7 years for women and 77.5 for men, versus a healthy life expectancy of 73.6 years for men and women.

The report divides the world into 14 different regions on the basis of geography and health development (see Annex), then analyzes the risks most important in each area and the gains in healthy life span that can be achieved. The top risks vary widely, from being underweight and unsafe sex in most of Africa to tobacco use and high blood pressure in North America, Western Europe and developed countries in the Western Pacific such as Japan.

The major risks reviewed in the report are responsible for a substantial loss in healthy life expectancy – on average about five years in developed countries and 10 years in developing countries. The amount of lost healthy life years due to these leading risks varies by region In Canada, the United States and Cuba (highest ranked group in the Western Hemisphere), healthy life expectancy can increase by 6.5 years, from their current healthy life expectancy of Canada, 69.9 years; Cuba, 66.6 years, U.S., 67.6 years. In the wealthiest countries of Europe, including Germany, France, Italy, Spain and the United Kingdom, healthy life expectancy can grow by 5.4 years; in most of Latin America, including Argentina, Brazil and Mexico, 6.9 years; in an Asian group including China, 6 years; in another Asian group including India, 8.9 years. (WHO estimates apply to each region as a whole and may not apply to any given country.)

A considerable part of this burden could be reduced by a set of cost-effective interventions identified in the report. WHO has developed a first-ever system of identifying and reporting cost-effective health interventions consistently across different regions that it calls CHOICE (CHOosing Interventions that are Cost-Effective). Various CHOICE options are contained in a new statistical database that is also a part of the World Health Report 2002, one of the largest research projects ever undertaken by the World Health Organization. These interventions can be implemented on an à la carte basis, depending on each country's individual circumstances.

“Although the report carries some ominous warnings, it also opens the door to a healthier future for all countries - if they’re prepared to act boldly now,” says Dr. Murray. “In order to know which interventions and strategies to use, governments must first be able to assess and compare the magnitude of risks accurately. Our report gives assessments for each of the major risks.”

Selected Major Risk Factors and What to Do About Them

The report shows that a relatively small number of risks cause a huge number of premature deaths and account for a very large share of the global burden of disease. For example, at least 30 per cent of all disease burden occurring in the highest mortality developing countries, such as those in sub-Saharan Africa and south-east Asia, results from underweight and deficiencies in micronutrients like iron and zinc, unsafe sex, unsafe water, sanitation, and hygiene and indoor smoke from solid fuels, the leading risks examined in those countries.

“Every country has major risks to health that are known, definite and increasing, sometimes unchecked,” says Anthony Rodgers, M.D., Ph.D., of the University of Auckland, New Zealand, and a WHO consultant who is one of the report’s main writers. “For each of these risks, we have established effective, but often underused, interventions.”

The report also breaks new ground by assessing avoidable death and disability at a global scale. By incorporating current knowledge in risk factor, demographic and mortality trends, an intriguing picture emerges – an increasingly ageing world facing some major risks globally (such as tobacco), as well as remaining very high mortality regions, particularly sub-Saharan Africa.

“This report brings out for the first time that 40 per cent of global deaths are due to just the10 biggest risk factors, while the next 10 risk factors add less than 10 per cent,” says Alan Lopez, Ph.D., WHO Senior Science Advisor and co-director of the Report. “This means we need to concentrate on the major risks if we are to improve healthy life expectancy by about 10 years, and life expectancy by even more.”

Given the risks measured in this Report and other known major risks, current scientific knowledge has clearly identified causes for most death and disability globally. For example, more than three-quarters of major diseases such as ischaemic heart disease, stroke, HIV/AIDS and diarrhoea were due to the combined effects of risks assessed in the Report. WHO emphasizes that each risk is also a prevention opportunity, and the potential for prevention from tackling major known risks is clearly substantial, and much greater than commonly thought. “Since many of these risks are continuous, without a threshold, the most cost-effective interventions are often those that move the entire population to a lower risk zone,” says Dr. Rodgers. “A good example would be government- and industry-led reductions of salt in processed foods, which would have major population-wide benefits.”

Underweight/under-nutrition -- Childhood and maternal underweight was estimated to cause 3.4 million deaths in 2000, about 1.8 million in Africa. This accounted for about one in 14 deaths globally. Under-nutrition was a contributing factor in more than half of all child deaths in developing countries. Since deaths from under-nutrition all occur among young children, the loss of healthy life years is even more substantial: about 138 million DALYs, 9.5 per cent of the global total.

Under-nutrition is mainly a consequence of inadequate diet and frequent infection, leading to deficiencies in calories, protein, vitamins and minerals. Underweight remains a pervasive problem in developing countries, where poverty is a strong underlying cause, contributing to household food insecurity, poor childcare, maternal under-nutrition, unhealthy environments, and poor health care.

Interventions -- The most cost effective strategy to reduce under-nutrition and its consequences combines a mix of preventive and curative interventions. Micronutrient supplementation and fortification - Vitamin A, zinc and iron – is very cost-effective. It should be combined with maternal counselling to continue breast feeding, and targeted provision of complimentary food as necessary. In addition, routine treatment of diarrhoea and pneumonia, major consequences of under-nutrition, should be part of any health improvement strategy for children.

Unsafe sex -- HIV/AIDS caused 2.9 million deaths in 2000, or 5.2 per cent of total. It also causes the loss of 92 million DALYs (6.3 per cent of all) annually. Life expectancy at birth in sub-Saharan Africa is currently estimated at 47 years; without AIDS it is estimated that it would be around 62 years. Current estimates suggest that 95 per cent of the HIV infections prevalent in Africa in 2001 are attributable to unsafe sex. In the rest of the world the estimated percentage of HIV infections prevalent in 2001 that are attributable to unsafe sex ranges from 25 per cent in Eastern Europe to 90 per cent or more in parts of South America and the developed countries of Western Pacific. Interventions -- Most people infected with HIV do not know they are infected, making prevention and control more difficult. Various sexual practices contribute to the risk of sexually transmitted infections. High-risk sex practices include multiple partners, together with lack of condom use and the type of sex acts involved. Treatments include:

  • Population-wide mass media health promotion using the combination of television, radio and printed media.
  • Voluntary counselling and testing.
  • School-based AIDS education targeted at youths aged 10-18 years.
  • Peer counselling for sex workers.
  • Peer outreach for men who have sex with men.
  • Treatment of sexually transmitted infections as a way of reducing transmission of HIV infections.
  • Treatment of mothers with HIV infection to prevent maternal to child transmission.
  • Anti-retroviral therapy has also been evaluated.
  • Intervention combinations: WHO says that the best way to address the problem is to apply a combination of the above interventions at a population-wide level.

High blood pressure and cholesterol -- Worldwide, high blood pressure is estimated to cause 7.1 million deaths, about 13 per cent of the global fatality total. Across WHO regions, research indicates that about 62 per cent of strokes and 49 per cent of heart attacks are caused by high blood pressure.

High cholesterol is estimated to cause about 4.4 million deaths (7.9 per cent of total) and a loss of 40.4 million DALYs (2.8 per cent of total), although its effects often overlap with high blood pressure. This amounts to 18 per cent of strokes and 56 per cent of global ischemic heart disease.

Blood pressure is a measure of the force that the circulating blood exerts on artery walls. High blood pressure levels damage the arteries that supply blood to the brain, heart, kidneys and elsewhere. Cholesterol is a fat-like substance found in the bloodstream that is a key component in the development of atherosclerosis, the accumulation of fatty deposits on the inner lining of arteries of the heart and brain.

Interventions – The World Health Report 2002 urges countries to adopt policies and programs to promote population-wide interventions like reducing salt in processed foods, cutting dietary fat, encouraging exercise and higher consumption of fruits and vegetables and lowering smoking. These are the most cost-effective interventions identified to reduce cardiovascular disease. This reflects recent evidence that such therapy benefits all groups at elevated risk, even those with average or below average blood pressure or cholesterol.

When added to this base, a combination of drugs -- statins (cholesterol lowering), low-dose blood pressure lowering medications and low-dose aspirin (blood-thinning) -- given daily to people at elevated risk of heart attack and stroke, would achieve very substantial additional benefits. This highly effective drug combination is likely to more than halve stroke and heart disease incidence and could be widely used in the developed world, and is increasingly affordable in the developing world.

"Our new research finds that many established approaches to cutting CV disease risk factors are very inexpensive, so that even countries with limited health budgets can implement them and cut their CV disease rate by 50 per cent,” says Derek Yach, M.D., Executive Director of the Cluster on Non-communicable Diseases and Mental Health. "In addition, drug treatments are increasingly affordable in middle and low-income countries, as effective drugs come off patent."

Tobacco Use -- WHO estimates that tobacco caused about 4.9 million deaths worldwide in 2000, or 8.8 per cent of the total, and was responsible for 4.1 per cent of lost DALYs (59.1 million). In 1990, it was estimated that tobacco caused just 3.9 million deaths, demonstrating the rapid evolution of the tobacco epidemic and new evidence of the size of its hazard, with most of the increase in developing countries.

Interventions -- Countries that have adopted comprehensive tobacco control programs involving a mix of interventions including a ban on tobacco advertising, strong warnings on packages, controls on the use of tobacco in indoor locations, high taxes on tobacco products and health education and smoking cessation programs have had considerable success. WHO found that for every 10 per cent real rise in price due to tobacco taxes, tobacco consumption generally falls by between 2 per cent and 10 per cent. In addition to national programs, an effective Framework Convention on Tobacco Control will address transnational aspects of the issues.

Nicotine replacement therapy (NRT) targeting at all current smokers was less cost-effective than the other strategies, but affordable in higher income countries. NRT includes nicotine patches, nicotine chewing gum, nicotine nasal sprays, lozenges, aerosol inhalers and some classes of anti-depressants.

Unsafe Water and Sanitation -- Approximately 3.1 per cent of deaths (1.7 million) and 3.7 per cent of DALYs (54.2 million) worldwide are attributable to unsafe water, sanitation and hygiene. Of this burden, about one-third occurred in Africa and one-third in south-east Asia. Overall, 99.8 per cent of deaths associated with these risk factors are in developing countries, and 90 per cent are deaths of children. Various forms of infectious diarrhoea make up the main burden of disease associated with unsafe water, sanitation and hygiene.

Interventions -- The United Nations has adopted a goal of halving the number of people with no access to safe water and sanitation by 2015. Improved water supply and basic sanitation, if extended globally, could prevent 1.8 billion cases of diarrhoea (a 17 per cent reduction of the current number of cases) annually. If universal piped and regulated water supply were achieved, 7.6 billion cases of diarrhoea (69.5 per cent reduction) would be prevented annually. Universal piped water is the ideal, but is high cost. In the short term, the most cost-effective strategy evaluated was disinfection of unsafe water at the point of use. This is a simple technology, is of very low cost, and would achieve substantial health benefits.

Iron deficiency -- Iron deficiency is one of the most prevalent nutrient deficiencies in the world, affecting an estimated two billion people with consequences for maternal and perinatal health and child development. In total, 800,000 (1.5 per cent) of deaths worldwide are attributable to iron deficiency, 1.3 per cent of all male deaths and 1.8 per cent of all female deaths. Attributable DALYs are even greater, amounting to the loss of about 25.9 million healthy life years (2.5 per cent of global DALYs) because of the non-fatal outcomes like cognitive impairment.

Interventions -- Iron fortification is very cost-effective in areas of iron deficiency. It involves the addition of iron usually combined with folic acid, to the appropriate food vehicle made available to the population as a whole. Cereal flours are the most common food vehicle, but there is also some experience with introducing iron to other vehicles such as noodles,rice, and various sauces.

“We surprised even ourselves in how far-reaching the health benefits can be if governments and health systems adopt our recommendations,” says Dr. Murray. “WHO believes that the wide distribution of this report should become a prime goal of all Member States.”

For further information please contact:

Dr Christopher Murray, Executive Director, Evidence and Information for Policy, WHO; Tel: (+41 22) 791 2418; Mobile: (+41 79) 217 3462; E-mail: murrayc@who.int

Dr Derek Yach, Executive Director, Noncommunicable Diseases and Mental Health, WHO, Tel: (+41 22) 791 2736; Mobile: (+41 79) 217 3404; E-mail: yachd@who.int

Mr Jon Lidén, Communications Adviser, Director-General’s Office, Tel: (+41 22) 791 3982; Mobile: (+41 79) 244 6006; E-mail: lidenj@who.int

Journalists can also call WHO press officers in Geneva: contact Helen Green, Information officer, Tobacco Free Initiative, Noncommunicable Diseases and Mental Health, WHO, Tel: (+41 22) 791 3432; E-mail: greenh@who.int or Thomson Prentice, Managing Editor, World Health Report, Tel: (+41 22) 791 4224; Mobile: (+41 79) 244 6030, E-mail: prenticet@who.int;

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For more information contact:

Dr Christopher Murray
Telephone: (+41 22) 791 2418
Mobile phone: (+41 79) 217 3462
E-mail: murrayc@who.int

Dr Derek Yach
Telephone: (+41 22) 791 2736
Mobile phone: (+41 79) 217 3404
E-mail: yachd@who.int

Mr Jon Lidén
Telephone: +41 (22) 791 3982
Mobile phone: (+41) 79 244 6006
E-mail: lidenj@who.int

Ms Helen Green
Telephone: +41 (22) 791 3432
Mobile phone: +41 (79) 475 5572
Fax: +41 (22) 791 4832
E-mail: greenh@who.int

Mr Thomson Prentice
Telephone: (+41 22) 791 4224
E-mail: thomsonp@who.int