**1. Introduction**

One of the greatest achievements of mankind in the last century was the increase in average life expectancy, mainly due to advances in public health, technology and medicine. While

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© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons

the twentieth century was the century of population growth, the twenty-first century will be known as the century of aging [1, 2].

The development of these chronic diseases occurs in several ways. There are malignancies such as lung or prostate cancer that are more common in the elderly population. An example of this condition is arthritis that may be present early but only with age it worsens and it manifests due to the senescence of the body in general. There are diseases that turn out to be a combination of the two factors, as with chronic respiratory disease, doubling its prevalence for each decade of

Adherence to Medication in Older Adults as a Way to Improve Health Outcomes and Reduce…

http://dx.doi.org/10.5772/intechopen.72070

27

Usually, older adults have multiple medical problems. Almost 50% of the elderly population has at least three chronic diseases, and of this, approximately 10% has five or more. These diseases can coexist for several reasons such as by random chance, because they are part of the same continuum, because they have risk factors in common or because one triggered the other [2]. Aging and comorbidities together increase the risk of hospitalization and

This "demographic time bomb" has direct consequences for the economy. With the increase of lifetime expectancy, more people are claiming for pensions, and less number of people are working and paying taxes, which will have an impact on national budgets. The economic growth will also be affected since higher savings for pensions may lead to the reducing of capital investments. At the same time, age-related diseases, comorbidities and geriatric syndromes are gaining attention in society, increasing the demand for health services. The elderly people require more health services, suffer more hospitalizations and occupy the bed longer than any other age group, thus increasing the money spent on

The main way to treat chronic illnesses is by using medicines. Although they are a powerful tool, its potential is not fully used, since half of the patients do not take them as prescribed, meaning they either do not take them or they do, but in the wrong dosage or in the wrong timing, failing to realize full benefits of treatments [14, 15]. Non-adherence is a huge problem that is directly linked with an increase in morbidity and mortality, costing between \$100 and

300 billion per year, in the United States (**Figure 1**) [16].

life after the 40 years [2].

mortality.

healthcare [13].

**Figure 1.** Non-adherence consequences.

Every second, two people celebrate their 60th anniversary [3]. Globally, in 2015, there were 901 million people who were 60 or older, most of whom are the elderly people living in developing countries. This number is expected to be more than double by 2050, reaching 2.1 billion (20% of total population). Interestingly, the number of people aged 80 or older is growing even faster than the elderly in general. By 2015, about 14% of the elderly population (125 million) were 80 or older, and that number is expected to triple by 2050, reaching 434 million (approximately 20% of the senior population) [4].

The speed at which the population is aging is dramatically increasing. For example, France needed 150 years to adapt from a change from 10 to 20% of the population over 60 years. However, developing countries such as India and Brazil have little more than 20 years to adapt to this reality [5]. In these countries, in 2010–2015, the average life expectancy was 68 years, but 78 years in the developed countries [3].

The increase in average life expectancy turns out to be an opportunity for older people and their families. With these extra years, the elderly can devote themselves to school again, can pursue a new career or can chase a lost passion [6]. But all of this depends on one key factor: health. WHO defined health as "a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity" [7].

From the biological point of view, aging occurs due to accumulation of damages, at both cellular and molecular levels. Telomeres are shortened as we age. Aging is characterized by changes in physical appearance such as gradual reduction in height and weight, due to loss of muscle and bone mass, higher reaction times, decline in memory, decreased sexual activity, reduced metabolic rate and a decline in auditory, olfactory and vision functions, as well as diminished lung, immune and renal functions. The speed at which aging occurs is determined by genetic and environmental factors [8]. Physical and social environments, as well as personal characteristics such as gender, ethnicity and socioeconomic status, are factors that affect the aging process from an early age. The environment has a huge influence on both the development and the maintenance of healthy habits. Lifelong healthy behaviors, in terms of diet, exercise and habits, contribute to the prevention of certain diseases [9].

Although this increase in average life expectancy is worthy of celebration, it must be borne in mind that increasing longevity has long-term consequences not only for health but for the health system and for economy too. There are health conditions that are associated with the increase in the elderly population. Cardiovascular diseases, cancer, chronic respiratory diseases and diabetes, the so-called non-communicable diseases are responsible for nearly 60% of the deaths, and they all share an unmodifiable risk factor such as age [10].

The major cause of death among the elderly in developed countries is cardiovascular diseases, accounting for 35% of all deaths [11]. Along with these diseases, cancer is the other major cause of mortality, being responsible for 22% of deaths [12].

The development of these chronic diseases occurs in several ways. There are malignancies such as lung or prostate cancer that are more common in the elderly population. An example of this condition is arthritis that may be present early but only with age it worsens and it manifests due to the senescence of the body in general. There are diseases that turn out to be a combination of the two factors, as with chronic respiratory disease, doubling its prevalence for each decade of life after the 40 years [2].

Usually, older adults have multiple medical problems. Almost 50% of the elderly population has at least three chronic diseases, and of this, approximately 10% has five or more. These diseases can coexist for several reasons such as by random chance, because they are part of the same continuum, because they have risk factors in common or because one triggered the other [2]. Aging and comorbidities together increase the risk of hospitalization and mortality.

This "demographic time bomb" has direct consequences for the economy. With the increase of lifetime expectancy, more people are claiming for pensions, and less number of people are working and paying taxes, which will have an impact on national budgets. The economic growth will also be affected since higher savings for pensions may lead to the reducing of capital investments. At the same time, age-related diseases, comorbidities and geriatric syndromes are gaining attention in society, increasing the demand for health services. The elderly people require more health services, suffer more hospitalizations and occupy the bed longer than any other age group, thus increasing the money spent on healthcare [13].

The main way to treat chronic illnesses is by using medicines. Although they are a powerful tool, its potential is not fully used, since half of the patients do not take them as prescribed, meaning they either do not take them or they do, but in the wrong dosage or in the wrong timing, failing to realize full benefits of treatments [14, 15]. Non-adherence is a huge problem that is directly linked with an increase in morbidity and mortality, costing between \$100 and 300 billion per year, in the United States (**Figure 1**) [16].

**Figure 1.** Non-adherence consequences.

the twentieth century was the century of population growth, the twenty-first century will be

Every second, two people celebrate their 60th anniversary [3]. Globally, in 2015, there were 901 million people who were 60 or older, most of whom are the elderly people living in developing countries. This number is expected to be more than double by 2050, reaching 2.1 billion (20% of total population). Interestingly, the number of people aged 80 or older is growing even faster than the elderly in general. By 2015, about 14% of the elderly population (125 million) were 80 or older, and that number is expected to triple by 2050, reaching 434 million

The speed at which the population is aging is dramatically increasing. For example, France needed 150 years to adapt from a change from 10 to 20% of the population over 60 years. However, developing countries such as India and Brazil have little more than 20 years to adapt to this reality [5]. In these countries, in 2010–2015, the average life expectancy was 68 years, but

The increase in average life expectancy turns out to be an opportunity for older people and their families. With these extra years, the elderly can devote themselves to school again, can pursue a new career or can chase a lost passion [6]. But all of this depends on one key factor: health. WHO defined health as "a state of complete physical, mental and social well-being and not

From the biological point of view, aging occurs due to accumulation of damages, at both cellular and molecular levels. Telomeres are shortened as we age. Aging is characterized by changes in physical appearance such as gradual reduction in height and weight, due to loss of muscle and bone mass, higher reaction times, decline in memory, decreased sexual activity, reduced metabolic rate and a decline in auditory, olfactory and vision functions, as well as diminished lung, immune and renal functions. The speed at which aging occurs is determined by genetic and environmental factors [8]. Physical and social environments, as well as personal characteristics such as gender, ethnicity and socioeconomic status, are factors that affect the aging process from an early age. The environment has a huge influence on both the development and the maintenance of healthy habits. Lifelong healthy behaviors, in terms of

Although this increase in average life expectancy is worthy of celebration, it must be borne in mind that increasing longevity has long-term consequences not only for health but for the health system and for economy too. There are health conditions that are associated with the increase in the elderly population. Cardiovascular diseases, cancer, chronic respiratory diseases and diabetes, the so-called non-communicable diseases are responsible for nearly 60%

The major cause of death among the elderly in developed countries is cardiovascular diseases, accounting for 35% of all deaths [11]. Along with these diseases, cancer is the other major

diet, exercise and habits, contribute to the prevention of certain diseases [9].

of the deaths, and they all share an unmodifiable risk factor such as age [10].

cause of mortality, being responsible for 22% of deaths [12].

known as the century of aging [1, 2].

26 Gerontology

(approximately 20% of the senior population) [4].

78 years in the developed countries [3].

merely the absence of disease or infirmity" [7].
