Factors associated with the frailty syndrome in elderly individuals living in the urban area 1

OBJECTIVE: to identify the occurrence and factors associated with pre-frailty and frailty conditions among elderly individuals. METHODS: this cross-sectional, observational and analytical household survey was conducted with 958 elderly individuals living in the urban area. The Brazilian version of the Functional Assessment Questionnaire and Multidimensional Scales (Depression, Katz and Lawton brief geriatric versions) were used, together with the Phenotype of Frailty developed by Fried. Descriptive analysis was performed along with a bivariate and multinomial logistic regression model (p<0.05). RESULTS: a total of 313 (32.7%) non-frail elderly individuals were found in addition to 522 (55.4%) pre-frail and 128 (12.8%) frail individuals. Factors associated with pre-frailty and frailty, respectively, included: being 70├ 79 years old and 80 years old or older; using 1├ 4 medications and 5 or more; greater number of morbidities, functional disability for instrumental activities of daily life, and negative self-perception. The absence of a partner was associated with pre-frailty while hospitalization in the last year, functional disability for basic activities of daily life and indication of depression were associated with frailty. CONCLUSION: pre-frailty and frailty conditions presented a percentage higher than that reported by Brazilian studies and are associated with health-related variables. These variables can be prevented with interventions directed to the health of elderly individuals.


Introduction
Frailty among elderly individuals can be defined as a geriatric clinical syndrome that involves a physiological state of increased vulnerability to stressors that result in decreased physiological reserves and deregulation of multiple systems. It is supported by a triad of changes related to the aging process: sarcopenia, neuroendocrine deregulation, and immune system dysfunction (1)(2) .
From the operational point of view, it is understood as a phenotype of frailty, proposed by Fried et al. (1) , which includes five components: unintentional weight loss, self-reported fatigue and/or exhaustion, decreased muscle strength, slow walking speed, and low level of physical activity. Hence, the presence of one or two criteria characterizes the pre-frailty condition, while three or more criteria characterize frailty (1) .
Frailty is considered a predictor of adverse outcomes, such as: comorbidities, falls, the use of healthcare services, health conditions, institutionalization, impairment, negative impact on quality of life, mortality, and its prevalence is particularly relevant for the field of public health (1)(2)(3) .
Brazilian and international studies have reported different prevalence rates, ranging from 6.9% to 40.6% among frail elderly individuals and 46.3% to 60.1% among pre-frail individuals. Associated factors include: being female, advanced age, low level of education and income; absence of a partner, living alone, negative health perception, functional disability, comorbidities, hospitalization, and indication of depression (1,(4)(5)(6)(7)(8) .
In this sense, the frailty syndrome should be a target of investigations and interventions given its impact on elderly individuals, their families and the society as a whole (2) . Despite recent initiatives (4)(5)8) , points for identifying cognitive deficit (9) .
The dependent variable, frailty syndrome, was identified through five items, described as components of the frailty phenotype proposed by Fried et al. (1) , as follows: (1) unintentional weight loss assessed by the question: "Have you unintentionally lost more than 4.5 kg or 5% of your body mass (that is, without diets or exercises) in the last year?"; (2) self-report of exhaustion and/or fatigue, week with physical activities. Individuals who met three or more of these criteria were classified as frail, those who met one or two items were considered pre-frail, and those whose scores were negative in the tests were considered robust or non-frail (1) .
The following were selected for the exploratory   Tables 1 and 2.
The association of pre-frailty and frailty with being 70 to 79 years old or 80 years old or older corroborates the findings of both Brazilian (5,8) and international studies (1,(6)(7) . The influence of aging as a predisposition for the development of the frailty syndrome may be related to changes and decline taking place in multiple systems, due to the interaction of physiological mechanisms and pathological conditions (1) with current and accumulated risks and functionality (4) . Nonetheless, even though aging predisposes to the frailty syndrome, not all elderly individuals are frail (16) or pre-frail, suggesting there are common but not identical elements. Hence, it is believed that this syndrome presents more accentuated characteristics than those regarding the normative process of physiological aging (17) .
The pre-frailty condition was associated with the absence of a partner; a similar result was found among Mexican pre-frail and frail elderly individuals (7) . A longitudinal study conducted in São Paulo, SP reports female elderly individuals separated or divorced present mortality rates 82% and 35%, respectively, higher than that observed among their married counterparts (18) .
In this sense, considering that the marital status is a component of the social support network of elderly individuals, we assume that, considering its complex interaction with clinical and social factors, the frailty syndrome sets in when there is rupture and/or absence of social ties (3,19) , considering a decline in physiological reserves (1) and the existence of stressful events or factors.
As opposed to other Brazilian and international studies (1,(5)(6) , the variables: sex, housing, education and income were not associated with pre-frailty and frailty conditions. Other variables, such as being a woman, having low income and education, and living alone pose risks to the development of the frailty syndrome (1,(6)(7) , suggesting that disadvantages such as economic, educational and health deficits accumulated over the course of life may contribute to the problem (4) .
In this study, the condition of frailty was associated with hospitalization in the last year, a result that disagrees with that reported by a study conducted in Belo Horizonte, MG, which found this association among frail and pre-frail elderly individuals (5) . Frail individuals experience decreased ability to respond to stressful situations, a vulnerability that predisposes them to chronic diseases, anorexia, sarcopenia, osteopenia, cognitive deficit and disabilities, which justify their greater susceptibility to adverse outcomes, such as hospitalization (1)(2) .
Additionally, intervening hospitalizations are strongly associated with mortality in the transition between states of frailty. Hospital environments may compromise the functional conditions of elderly individuals, hindering recovery from frailty and prefrailty conditions. These findings show the need for actions to reduce hospitalizations due to evitable causes, preventive measures to avoid hospital complications (20) , and the implementation of care protocols that take into account admission, procedures, surgeries, time of hospitalization, hospital discharge and post discharge.
The pre-frailty and frailty conditions remain associated with a greater use of medication, especially among those taking 5 or more medications. This finding was also reported by an international investigation in which polypharmacy was associated with increased prevalence and incidence of frailty among communitydwelling elderly individuals (21) . Polypharmacy is considered a risk factor for frailty among the elderly (21) , in which the overlap of multiple medications, indiscriminate use of medications, and associated side effects (22) , may aggravate this condition. Moreover, the association between frailty and chronic diseases in this study indicates that the greater use of medications may reflect the manifestation of comorbidities.
This study's results include the association between pre-frailty and frailty and morbidities, corroborating Brazilian (5,8) and international (1)(2)7) studies. Frailty and chronic diseases function as modulators of an individual's health, suggesting that understanding the presence or absence of these conditions may favor the representation of physiological reserves in old age (22) .
Frailty may enhance the development or progression of chronic diseases, possibly because of decreased levels of activity or the progression of other conditions that affect mechanisms responsible for homeostasis, such as inflammatory processes and sympathetic-parasympathetic balance (2) .
Additionally, frail elderly individuals experience increased vulnerability to stressful events, such as the manifestation of pathological processes due to low energetic reserves and/or their inefficient use, which result from a pathological response of the limited physiological reserve of this syndrome (22) .
Disability or dependence for the performance of instrumental activities of daily life was associated with the conditions of frailty and pre-frailty, however, disability to perform basic activities of daily life was only associated with frailty. Brazilian (5,8) and international (1,7,23) studies also report associations between frailty and disability to perform BADL and IADL. Despite distinctions in their theoretical conception (2) and confusion regarding the definition of frailty and disability due to the similarity between their adverse outcomes, frailty predicts disability among elderly individuals (23) , which in turn, is seen as a outcome or contributing factor, potentially aggravating frailty and comorbidities (2) . Therefore, there is a need for care actions directed to the organization of healthcare services, family and society to cope with this scenario, in order to delay or alleviate functional decline in elderly individuals, taking into account frailty conditions, and specially pre-frailty, to promote an active aging process (5) .  (24) .
Pre-frail and frail elderly individuals present 67% and 82% more chances, respectively, of presenting a negative health perception, a result that agrees with that reported by other studies (6,8) . Given characteristics inherent to the condition of frailty and pre-frailty, such as decreased ability to respond to stressful conditions and greater susceptibility to adverse events (e.g. the progression of diseases), it is believed that these aspects justify such an association. On the other hand, it is possible that the perception of elderly individuals with regard to adverse events experienced over the course of life (8) , such as: personal experiences, goals, and mechanisms used to overcome disappointments and failures, may predispose to the frailty syndrome (8) .

Conclusion
The conditions of frailty presented a percentage