Biomedical Engineering Reference
In-Depth Information
Older age, female gender, and low socioeconomic status were found to be the main causes
of multimorbidity, whereas disability and functional state decline, poor quality of life, and
high health-care costs were the major consequences of multimorbidity (Marengoni et al.
2011). Considering epidemiological data on mental disorders in the older population, it is
important to know that comorbid mental disorders are associated with functional status
and quality of life, and that mental disorders increase the risk of death (Gijsen et al. 2001).
In particular, dementia and depression are very common mental disorders in the elderly
population. Approximately 24 million people have dementia in the world, with the num-
ber being projected to double every 20 years. Approximately 60% of dementia patients
live in developing countries, and this proportion is predicted to increase to more than
70% by 2040 (Qiu et al. 2007). With respect to attendance rates due to the various forms of
dementia, the main cause is Alzheimer's disease (50-80% of dementia cases), followed by
Lewy body dementia (20%) and vascular dementia (5%; Corey-Bloom 2004). Considering
the epidemiology of depression in the elderly, Alexopoulos (2005) reported 1-4% for major
depression and 4-13% for minor depression. The incidence and prevalence of depression
is double this in the oldest old, and the prevalence in medical settings is higher than in
the community. Late-life depression is common in individuals with medical and psycho-
social problems such as cognitive impairment, diseases, and social isolation. The care of
depressed older people is complicated by a reciprocal interaction of depression with dis-
ability, medical illness, treatment adherence, and psychosocial factors (Alexopoulos et al.
2002). Depression is a predictor of disability in both sexes; in fact, it causes physical and
social inactivity and the psychological aspects of depression even provoke a sense of dis-
ability (Tas et al. 2007).
13.2.2 Disability
Considering the interaction between disease and the environment, the concept of disabil-
ity, in a biopsychosocial perspective, is an important aspect to consider in a society with
an increasing number of old people. In a recent study (Landi et al. 2010), physical disability
in aging was described as an effect of diseases plus physiological alterations connected
to aging. In this view, social, economic, and behavioral factors and access to medical care
modify the impact of the underlying causes. At the same time, disability is considered
as an adverse health outcome and a risk factor for other adverse health outcomes. On the
basis of several studies, the authors wrote that “disability, independent of its causes, may
predict subsequent difficulty in instrumental and basic activities of daily living, and it has
been associated with an increased risk of death, hospitalization, need for long term care,
and higher health care expenditures” (Landi et al. 2010, p. 752).
During the last few decades, different scenarios have been proposed concerning the
patterns of health trends in older people; these were resumed by Jagger (2000):
1. The compression of morbidity theory suggests that disease and disability will
become compressed into a short period before death if changes in lifestyle delay
the age -at onset and the progression of nonfatal disabling diseases (Fries 1980).
2. The opposite view, namely the expansion of morbidity theory, proposes that living
longer implies living with a disabling disease such as Parkinson's disease, demen-
tia, vision and hearing loss, and arthritis (Kramer 1980).
3. The third theory supports a dynamic equilibrium between an increase in the
number of years lived with a disability and the number of years lived with a less
severe disability (Manton 1982).
