Epidemiology of the elderly

The sociological changes of the world population are occurring rapidly not only in the more developed countries (MDCs) but also in the less developed countries (LDCs). At present, the world has over 6 billion persons and this number is expected to reach 10 billion within next 50 years, with the majority of the change occurring in the LDCs. In fact, by 2050 over half of the world's population will be in eight countries, all LDCs except the United States of America. The greatest transformation occurring is the aging of the world's population. Western Europe and North America now have about 14% of their population over the age of 65, which is expected to increase to 25% within 50 years. Even more alarming is the proportional increase in the eldest-old group over the age of 85. Concomitant with this aging phenomenon, is a greater expenditure on health as the elderly need more aid in their activities of daily living. The elderly presently utilize up to 30% of the medical services of a country and diseases of the gastrointestinal tract have become a major contributor to this burden. This chapter relates to the epidemiology of the elderly, relating also to the gastrointestinal tract.