**2. Epidemiology**

responses to the different noxas, placing them in a state of greater vulnerability, which has an effect of greater comorbidity, loss of autonomy, disability, sensory alterations, cognitive deterioration, and a social-familiar problematic that can occur simultaneously, determining a special difficulty for their evaluation and treatment and, many times, altering its prognosis

In this way, the concept of biological aging is important, understood as the state of an individual resulting from the wear and tear associated with age plus its conditions of illness, functionality, mental well-being, and social support. This biological aging is very different among the elderly, regardless of their chronological age and condition differences in the functional

In a recent Spanish study, it was established that older patients had a higher priority in the care by severity, had more complementary tests taken, had a longer average stay, had a higher probability of hospital admission and of being exitus, and needed assessment by the social services. In addition, it requires more complex evaluations, more consultations with other specialists, and a higher percentage of readmissions [5]; however, they attend in a justified manner and with a significantly used pattern different from young adults. Therefore, the progressive aging of the population may seriously affect the dynamics and functioning of the

In young patients admitted to an emergency department, it has been determined that there are undoubtedly clinical factors related to the acute disease, which decisively influence the outcome. However, this is not so clear in the elderly, and the characteristics that go beyond the severity of the acute disease modify the prognosis. More specifically, these conditions refer to the functional, emotional, and cognitive states, the level of comorbidity, the degree of polypharmacy, and the social support networks. Due to their condition of high vulnerability or fragility, in the elderly patients, the health problems are explained in the multicausality model, and the resolution of these does not derive from the attention of a single cause, but from a comprehensive identification and treatment of all related factors that affect

Hospitalization alone is already a negative factor in the outcome of elderly patients. Survival decreases by the mere fact of being reduced to a hospital bed, immobilized, both in men and women, but above all in the older groups (>80 years) [7]. Even if you take into account that the emergency services are noisy, in constant movement and lack of privacy, which can be disconcerting for the elderly and enhance their deterioration in relation to hearing, vision,

In general, the elderly patients have a longer stay in the emergency department, requiring more time for medical assessment and nursing care, and alarmingly they have a higher frequency of readmissions, generating a great assistance pressure on the professionals that

The lack of knowledge of the elements that affect the prognosis of the elderly patients in the emergency services is still notorious, which results in diagnostic errors and what is more

adversely [3].

86 Gerontology

capacity [4].

hospital emergency services.

the prognosis [6].

attention, and understanding.

attend these services [8].

Recent studies have shown a progressive increase in emergency visits, which is much more noticeable in the elderly population. In fact, some studies mention that up to 25% of all emergency visits correspond to elderly patients. In general, they represent more than 15% of all consultations and almost 50% of all admissions to intensive care units. Therefore, some authors mention that "the emergency units are aging" [9].

In the United States, the Centers for Disease Control and Prevention (CDC) report that between 1993 and 2003, there was an increase in the absolute number of visits to the emergency department, with the group of people over 65 years of age, who had the highest frequency of visits (an increase of 26%). If this trend is maintained, it is expected that the frequency of emergency consultations in the elderly will double from 6.4 million to 11.7 million by 2013 [10]. Elderly patients are four to six times more likely to be admitted to an emergency unit than a nonelderly patient.
