INTRODUCTION
As we enter the final decade of the twentieth century, we are witness to marked increases in life expectancy in almost all countries of the world. Life expectancy at birth for the world as a whole has risen from 51.5 years for the period 1960-1965 to 61 .5 years for the period 1985-1990 - an increase of ten years of life in only twenty-five years.
While some of the improvement in statistics is due to demographic variables, there can be no doubt that the increase in life expectancy is a real trend, attributable to impressive achievements in technological and socioeconomic development, and to specific, targeted, action taken to implement the WHO policy and strategy for health for all. Nevertheless, crucial questions remain as to the overall quality of additional years gained. On one side are those who perceive as positive the results of general and specific preventive activities that have increased the health status of older persons. The incidence of serious diseases has been reduced, and observations suggest that many of the elderly are more vital than ever before. On the other side are those who cite the "failures of success" of medical advances, and warm of a "rising pandemic" of elderly people suffering from chronic diseases. The truth may encompass both sides. I believe we must look at the elderly, not from the point of view of whether they are well, or suffering from a degenerative disease, but rather from the aspect of quality of life.
The World Health Organization defines health as a state of physical, mental and social well-being and not only the absence of disease or infirmity. In this context, healthy aging should be measured in terms of achieving the goal of making the later years of life vigorous, active and satisfying, instead of merely adding years to life.
Questions relating to the quality of life are not only of great human and scientific importance, they also address social consequences, and their implications for planning health care and social services are enormous. The elderly population is far from homogeneous; even in one small geographical area or country there is no "typical" old person. Yet the needs of each must be taken fully into account.

1. WHAT CHARACTERIZES OLD AGE?
Old people differ from younger adults in their greater physical and psychological vulnerability. Aging is characterized by a loss of adaptability of an individual organism over time. This loss of adaptability, due to a loss in functional reserve, is perhaps the outstanding feature of aging. Often vulnerability is compounded by an adverse environment and social discrimination.
Many theoretical issues as to the nature and cause of aging remain unanswered. What we do know is that aging is a complex phenomenon. The most important determinants of longevity and age-associated morbidity lie in primary aging, due to the interaction of genetic or environmental influences. Secondary aging encompasses the adaptations made to overcome the effects of primary aging, and it exists on an individual as well as on a species level.
In this regard, determinants of healthy aging, and the health and social needs of aging populations, within a life-time context, are closely associated with biological, psychosocial, cultural, environmental and economic factors. Some age-associated diseases, such as coronary heart disease, are vivid examples of how genetic predisposition to disease can be influenced favourably by a change in lifestyle, such as in smoking, dietary or exercise habits.

2. INTERNATIONAL DEMOGRAPHIC TRENDS
Countries that have sustained falls in fertility and have made progressive reductions in mortality have growing proportions of older citizens. This is dramatically illustrated by the experience of China. A very large and growing population led China to adopt, in the late 1970s, a policy of reducing fertility by encouraging married couples to restrict their families to one child. Effective implementation of this policy would have resulted in a significant proportion of the population being over the age of 65 years by the middle of the next century. This would be much higher than the level which Sweden, currently the country with the world's oldest population, expects to attain by 2025. By that year, 23.4% of Swedes will be in the 65-year and over age group. The corresponding proportions for the rest of Europe, Japan and the United States will be 20.1%, 23.7% and 19.6% respectively.
Currently, some 29 countries have two million or more people aged 65 years or more. Even before the year 2000, China will have more than eighty million citizens in this age group, and India will reach this mark around the year 2015.

Fig 1 Population aged 60 years and over, by world regions, 1960-2020

Fig. 1 shows the population aged 60 years and over, by major geographical areas of the world, in 1960 and in 1980, and projected for the year 2000 and beyond. While there is a balance in elderly population today, you will notice the enormous number of older persons in developing countries, and particularly in Asia and Oceania, expected by the year 2020.
In several developing countries, the population aged 60 years and over is increasing at a faster rate than the population as a whole. Thus, while between 1980 and 2020, the total population of the developing world is expected to almost double, the elderly population will probably more than triple.
While in European countries, where it began much earlier, the process of population aging is slowing, and even leveling off, in some parts of the globe countries are outpacing the historical and predicted trends.

Fig. 2 Projected increase in the elderly population between 1980 and 2020 for the 20 countries with the largest elderly population in 1980*

Fig. 2 shows the expected increase in the elderly population between 1980 and 2020 for the twenty countries with the largest populations as at 1980. You will note that the increases are among the lowest in the United Kingdom, Spain, Italy and France, for example, but highest in China, India, the U.S.A., the U.S.S.R., Indonesia and Brazil. Japan, for example, has a high percentage of annual growth rate of older people, which will bring the pro portion of its citizens aged 65 years and over to 14% of the total population by the year 1996 - double the 1970 proportion over a period of 26 years. The rate of increased longevity in Europe and North America has been much slower.

Fig. 3 Span of years required for the population aged 65 years or more to transit from 7% to 14% of the total population

As you can see in Fig. 3, it has taken France over 115 years for the population aged 65 years and over to grow from 7% to 14% of the total population. It took Sweden over 80 years, the U.S.A. over 60 years and the United Kingdom over 40 years, compared with only 26 years for Japan.
With the exception of Africa, the developing regions of the globe are expected to achieve the World Health Organization's objective of attaining, by the year 2000, a life expectancy at birth of 60 years. While there is considerable heterogeneity within the developing world, the average life expectancy at birth is still about 14 years lower in the developing, than in the developed world. Japan's life expectancy, which was 77 years in 1985, is the highest in the world.
In most countries, elderly women outnumber elderly men, greatly so at advanced age, especially in the industrialized countries.

Fig. 4 Percentage of population female at age 80 years and above in 1985

Fig. 4 shows the percentage of population that is female at the age of 80 years in selected countries. You will note that women represent over 60% in Germany, the U.S.A., China and Japan. In India, however, women represent only 50% of the population over 80 years of age.
A further trend is the increase in life expectancy at the age of 65, which outpaces that at birth. While in Japan life expectancy at birth increased by only 12% between 1960 and 1980, the average number of years remaining at the age of 65 increased from about 13 to about 17.

Fig. 5 Trends in life expectancy at age 65 years, in selected developed countries, 1950-1986 (calculated as 5-year averages)

Fig. 5 shows trends in life expectancy of men and women at the age of 65 in selected countries. You will notice that the gains are consistently higher for women, on the right-hand side of the screen, especially in developed countries. The gains for men are highest in Japan, but much higher still for women, especially in France.

Fig. 6 Trends in life expectancy at age 65 years, in selected developing countries, 1955-1984 (calculated as 5-year averages)

As shown in Fig. 6, in developing countries life expectancy at the age of 65 has increased for both men and women, but again the gains are markedly higher for women, especially in Panama.
There seems little reason to doubt that, as economic advances take place, in most countries women will tend to live longer than men. Also, unless there is a change in the widespread tradition of men marrying women younger than themselves, we can expect a disproportionate increase in the number of elderly widows whose husbands have pre-deceased them by many years. Few, if any, developed countries have been able to establish social and financial support systems appropriate to this challenge.
Life expectancy is closely related to social and economic development.
The vast differences between regions and countries remind us of the serious issue of equity or its absence, when considering health for all at a global level. At the same time, we must realize that success in raising life expectancy will increase the costs of health care services in countries least able to afford them.
Advancing age increases the demand for the more expensive medical, social and economic services. Developed countries have a per capita spending of about US$ 1000 on health care, of which 60% goes to people over 65 years of age. Developing countries, on the other hand, still face problems associated with their younger populations and are unable to spend more than about US$ 75 per person per year on health.
Table 1 Ratio of per capita public health expenditure on elderly to non-elderly in selected OECD countries

Table 1 shows the ratio of per capita public health expenditure for elderly and non-elderly persons in selected industrialized countries. You will note that on average a person aged 65 and over costs more than five times as much as a person under 65, and a person aged 75 and over costs nearly six times as much. Is this what developing countries have to look forward to? We must be sure that it is not.
These facts have significant implications for the economic sustainability of future health systems, and it is for this reason that the World Health Organization is placing increased emphasis on health economics, and methods of financing, including social security and health insurance.

3. HEALTH AND ILLNESS
Emerging understanding of health and morbidity in old age reveals the limited scope of the conventional medical model. The WHO conceptualization sees illness-related phenomena in a much broader frame, distinguishing among different aspects of disease - impairment, disability and handicap. While impairment denotes anatomical or physiological morbidity, disability relates to a decline in self-care in daily living activities, and handicap interferes with the individual's ability to carry out social functions and obligations. This broad view is especially relevant for chronic, progressive or irreversible disorders, which become more frequent with rising age.
The nature of aging also has implications for approaches to the prevention of disease and disability in later life. Epidemiological evidence suggests that 70% or more of adult cancers are environmentally caused. Reduced blood cholesterol is expected to reduce the risk of heart disease, and exercise has a beneficial effect on functioning capacity and bone density.
The relationship between ethnicity and environment in the determinants of age-associated diseases can be observed in a natural experiment in Japan. While the cause of dementias is mostly of a cerebrovascular nature in Japan itself, the Japanese population of Hawaii shows the western pattern of a predominance of the Alzheimer's type of dementia.
In some countries, blood pressure control appears to have contributed to a decline in the incidence of stroke. The effect of cigarette smoking or morbidity, and its relationship to accelerated aging, are well documented, as is the potential benefit of stopping smoking.
Environmental measures, as well as life-style changes must be focused on. Nevertheless, it seems that if widely distributed benefits are to be obtained from knowledge about preventive approaches to health, governments must have a direct hand in influencing incentives and disseminating knowledge. The reduction in related mortality produced by increasing the cost of alcohol and cigarettes is well known, although ignored by governments committed to sharing in the profits of the tobacco and alcohol industries. Pollution of air and water through industry also demands government intervention.
When considering health and illness in the elderly, we must focus or two major issues. The first relates to the opportunities for personal growth; third careers and new lives when historically it was assumed that life was drawing to an end. The second is the threat of "survival of the unfittest"; many more human beings surviving in a state of prolonged dependency, in need of comprehensive services.
Assessment of health status among the elderly on an international basis is essentially limited to the use of mortality data, since these are the only comprehensive data available. It must be recognized that mortality data do not always accurately reflect the underlying morbidity, particularly when multiple pathological conditions are often present at the time of death.
In the developed countries at least, roughly 50% of all deaths between the ages 65 and 74 years are attributable to a cardiovascular disease. Cancer accounts for one-quarter of deaths among men and women aged 65 to 74 years. Increased life expectancy at age 65 is due to the wide availability of drugs, antibiotics in particular, and to falling death rates from ischaemic heart disease and stroke, largely due to healthier lifestyle. Fig. 7 shows the age- specific mortality from heart disease for men aged 65 to 74 years, in Australia and the U.S.A.. Note how the rates from 1965 to 1969, shown in black, compare with the rates from 1980 to 1983. The declines are remarkable.

Fig. 7 Age-specific mortality per 1000 men aged 65 to 74 years from heart disease

Fig. 8 Age-specific mortality per 1OOO men aged 65 to 74 years from cerebrovascular disease

The situation is even more dramatic for reduction in age-specific mortality from cerebrovascular disease in Japan, as shown in Fig. 8. You will note that for both men and women in the age group 65 to 74 years, age-specific mortality from cerebrovascular disease fell, between 1980 and 1984, to about one-third the level they had been two decades previously.
In contrast, little progress has been made in Japan in lowering cancer mortality.

Fig. 9 Trends in mortality from leading causes of death at age 65-74 years, in selected countries, 1950-1984 (calculated as 5-year averages)

As shown in Fig. 9, malignant neoplasms, which are indicated by the solid line in the middle of the diagram, continue to rise, in the face of marked declines in heart, cerebrovascular and respiratory diseases. The challenge for the remaining years of the twentieth century is to find ways of achieving the same declines in cancer death rates as those in the other diseases.
When considering the social impact of disease and human suffering, serious attention must be given to the dementias. Their prevalence rises sharply with age, from an estimated 5% in the 65 to 74 year age group to over 25% in the 85 and over age group. Over the past three decades the average case duration of these diseases has risen from 4 to 12 years. Dementing illnesses pose a major challenge to the health and social services of the developed countries, and it seems likely that developing countries will also have to face this most difficult problem in the not too distant future.

4. KNOWLEDGE DEVELOPMENT
Much as is already known about aging, there are four major areas on which research must be focused.
(1) First, there is a need better to understand the biological processes underlying primary and secondary aging.
(2) Secondly, there is a need for greater understanding of the nature of disease, including impairment, disability and handicap, as well as appropriate interventions, taking into account the intricate interaction between physical, psychological, social, cultural and environmental factors.
(3) Thirdly, there is a great need for health care services research to identify the kind of health and social services needed by the elderly, their families and the communities in which they live, and at what cost, in order to match increasing life expectancy to increasing quality of life. This research will have to focus on the needs of family caregivers, who are mostly women. These caregivers shoulder a heavy burden, which is so well described in the best selling Japanese novel by Sawako Ariyoshi, "Kokotsu no hito - The Twilight Years".
(4) Finally, to improve the status and well-being of the elderly it is necessary for societies to adopt active measures to counter "age-ism" and accept that aged persons form a heterogeneous group, each entitled to equity in its own right. That is, a positive attitude and positive behaviour on the part of society which will preserve the rights of older persons to live and die with dignity.

(1) Education
While traditional values of respect for the elderly are to be found throughout the world, reinforced by the major religious teachings, negative stereotyped attitudes to aging and the aged are also universal. They are not restricted to modern, achievement-oriented societies. In many cultures, respect and negative attitudes tend to exist side by side. The demands of modernization and rapid change reinforce the notion that the old have nothing of value to contribute to society, and so must make room for the young. The answer lies in social education, with particular attention to three major groups: the wider public and society as a whole; the elderly themselves; and health care personnel. Such education must begin early in life, in the home and at school, and must be transmitted through lay groups, such as women's organizations, trade unions and religious groups. People everywhere must grasp the implications of the demographic transition, and the necessity for communities to be responsive to the needs of their elderly.
The elderly themselves are often affected by society's negative stereotyped attitudes towards them. It is difficult not to fall victim to self-defeating prophecies of illness and dependency. Helping the elderly to accept responsibility for selfcare; to realize when medical attention can be beneficial and when it may be harmful (e.g. polypharmacy); to continue active lives; and to accept dependency when it is unavoidable, without loss of self-respect, are some of our educational goals.
Knowledge relevant to aging must be integrated with basic and continuing education of health care personnel, so that they have the attitudes and skills for giving the elderly the care and attention they deserve. While, in some parts of the world, nursing curricula have been revised to address the specific needs of the elderly, much remains to be done to improve practice, and to develop interventions for improving the quality of life.

(2) Policy
Of all the difficult issues I have mentioned, perhaps the most challenging and controversial is that of health and social policy. There is understandable concern that the growth of the elderly population will inevitably be associated with rising expenditure on expensive care. While this fear is not unfounded, much can be done to prevent such a development. Several crucial areas deserve attention.
First, it must be realized that the growing healthy elderly population can be a source of economic development by continuing to contribute to the workforce, and as an important consumer group in its own right;
Secondly, there is a crucial need to secure a basic income for elderly people. Social security can play an important role in the maintenance of income during old age. In many countries, however, further development and changes are needed to make these social security systems economically viable and responsive to growing needs.
Thirdly, the needs of the elderly must be taken into account when planning for future urban development, public housing, public transport and other facilities. These aspects are crucial to preventing excess disability, which then unnecessarily creates the need for expensive care.
Whenever long-term care is needed, a wide range of services must be planned - from community care, including day care, home care, and social services, to hospital and institutional care. It seems to be a general rule that, in countries with universal access to health care services, more expensive care, for example in hospital, is a substitute for less expensive services if they are not readily available.
Lack of sheltered housing, home visiting or repair services may lead to unnecessary institutionalization. The answer to inadequate community services is often expensive hospital beds.
Since no government can afford to be the main source of care for dependent elderly people, services must include support to families. Even in the industrialized countries, more than 80% of care for the impaired elderly is given by their family. This vital unpaid workforce must be preserved, by pro viding specific support if necessary.
To draw attention to the growing need of society, and of families, for services, here is an example which shows the steep increase in the number of bedridden and demented aged expected in Japan.

Fig. 10 Projected number of aged people with senile dementia and of bedridden elders, Japan 1986-2025

Fig. 10, the tops of the bar graphs represent the total number of bedridden aged persons in Japan in 1986, today, and projected up to the year 2025. The black portion represents the number of persons with senile dementia. Both figures are growing rapidly. The time to prepare for these trends is now.
Planning for health professionals must take into account the fact that few areas are as dependent on multidisciplinary work as is good care of the elderly. While physicians diagnose and treat ailments amenable to intervention, nurses and nursing support personnel must provide both care and education in self-care, in the community, hospitals and institutions. Other disciplines are also needed, such as social workers and rehabilitation personnel.
All health care personnel should be educated in the special conditions and needs of older people. And they should learn the most effective methods of preventing and managing disease and disability. In addition, a relatively small group of clinicians - physicians, nurses, and others - should be prepared to provide guidance to general practitioners. And a cadre of faculty and investigators in the different disciplines must provide leadership in teaching and research.

5. SUMMARY
In summary, I have touched on a wide range of issues; from the global demographic transition, and social issues such as urbanization, poverty and the special situation of old women, to morbidity trends and the need to view health and health care of the elderly within a broad and comprehensive frame. Providing equitable and appropriate health care to the elderly is one of the greatest challenges facing us, extending well beyond the WHO goal of health for all by the year 2000. It is a challenge demanding policies and programmes that will ensure the availability of health and social services for older people, and will promote their continuing enjoyment of a socially and economically productive life.
While we wish that governments could learn from the experience of others who have had to face the problem earlier, this is a most difficult challenge. None of the economically advanced countries have planned ahead for their aging populations; partly because they have not appreciated the enormity of developments; partly because they have lacked the political will; partly because, during the crucial years, they have been preoccupied with other matters, such as war and reconstruction; and, more importantly, because they have not had past experience to draw on. They have been forced to apply inappropriate models of care. Many of their services are thus expensive, and do not respond to the variety of needs of an elderly population.
The rate of demographic transition is expected to be much more rapid for developing countries than it was for some of the industrialized countries. If they are not to repeat the mistakes of the industrialized countries, developing countries need innovative and creative leaders. They must appreciate emerging demographic realities, rally political will, and create a climate of care and support for the elderly. In times of great economic hardship and social upheaval this seems a task close to impossible.
Traditional values of family responsibility and social cohesion will only survive if this challenge is taken up by society and government as one. The unprecedented growth of the elderly population, while a threat on the one hand, is, on the other hand, an opportunity that might lead individuals and governments alike to discovr new ways of caring, and to become truly interdependent. In this way, old cultural values may be preserved, and scientific advances may become a real step in the service of the people.