Prevalence of household falls in long-lived adults and association with extrinsic factors

Resume Objective: to identify the prevalence of falls among older adults and the extrinsic factors associated with them. Method: population-based cross-sectional study with 350 older adults. A household survey was conducted using a questionnaire addressing socio-demographic, clinical, and environmental characteristics. Data were analyzed using Stata Software V.10. Pearson’s chi-square test and logistic regression analysis were used with stepwise criteria for selection of variables in the model, with measures of effect expressed in Prevalence Ratio. For input into the multiple model, the variables with p ≤ 0.20 were considered. All ethical care regarding research on human beings has been observed and respected. Results: the prevalence of falls was 46.9%. The extrinsic factors associated with falls were: stairs, uneven floor and pets in the main entrance, lack of anti-slip loose throw rugs and slippery floor in the kitchen, lack of anti-slip loose throw rugs and objects on the floor in the room, lack of grab bars in the shower, lack of grab bars in the toilet and switch away from the bathroom door (p <0.05). Conclusion: falls are frequent in long-lived adults. The identification of the extrinsic factors associated with the occurrence of this event can help in its prevention.


Introduction
The aging phenomenon is marked by changes in the demographic structure and in the socioeconomic and health conditions of the population. Its repercussions are felt both by society and by the health system (1) . These transformations demand a more thorough study of this segment and of the problems older adults are exposed to, such as events associated with falls.
The occurrence of falls is considered one of the main external causes of morbidity and mortality among the older adults. A fall is defined as any unexpected contact with the ground by any part of the person's body, except for the soles of their feet (2) . Events associated with loss of consciousness, blunt cerebrovascular injury, car accident, vigorous recreational activity or violence are often excluded from the definition of falls in older adults (3) .
Falls provoke an important loss of autonomy in older adults (4) and can cause different consequences, such as mild injuries, fractures and even death (5) . These consequences have an impact on health services, since they increase the use of personal and material resources for medical and nursing care. For this reason, falls are considered the most costly injury among older adults (6) .
Older adults over 80, considered long-lived adults, have alterations in their organism. Among them, sensory and musculoskeletal alterations stand out, since they can cause damages such as an increase in the risk of falls and a reduction in the level of functional independence and, consequently, lead to a decrease in quality of life (3) .
In fact, throughout their lives, besides the changes in the biological, psychological and social dimensions, older adults are exposed to several situations that can lead to loss of autonomy and independence, such as the occurrence of falls (7) .
In Brazil, about 30% of older adults suffer falls at least once a year. One in three older adults aged 65 years or older fall one or more times, and half of the older adults who fall suffer a recurrence (8)(9) . Approximately 2.5% of them require hospitalization; of these, only half survive after one year (9) . The risk of falls almost doubles in individuals over 80 years old. For the long-lived adults, the percentage rises to approximately 50% (10) .
The cumulative effect of changes related to age, diseases and an inadequate environment may predispose people to falls (11) . These events may be associated with risk factors for falls, which may be multifactorial and related to intrinsic and extrinsic factors (12) .
Intrinsic factors are those related to the individual, resulting from the physiological changes brought by aging, the presence of diseases, psychological factors and adverse reactions to medications (9) . Extrinsic factors refer to the behaviors and the activities of older adults and their physical environment, factors that depend on social and environmental circumstances (9) .
In the review of the specialized literature, a study addressing the interaction of older adults with the environment in relation to falls was found (13) . The findings highlighted the interactions between personal factors and the environment, however, it was not possible to find conclusive answers regarding the relationship between older adults and the environment and the risk of falls. The knowledge of these factors is an important asset for the health care team to establish the necessary foundations for a care system and, consequently, propose measures to prevent future falls.
Regarding the falls suffered by older adults in the community described in the international literature, the greatest interest has been the prevention of falls (14) . On the other hand, most of the studies were conducted in the South and Southeast regions, and the most assessed aspects were: prevalence, incidence, causes and consequences of falls, risk factors and profile of older adults who fell (3)(4)8) . Therefore, studies addressing extrinsic risk factors for falls in older adults are important in order to understand the magnitude and characteristics of this event.
In this sense, a gap in the literature addressing this problem is identified. An extensive review of the literature performed by Spanish-speaking authors revealed there is only a single research addressing the problem of falls in a nursing home (15) , which identified

Results
The sample of this study consisted of 350 longlived adults, ten more than the result obtained from the sample calculation, with a mean age of 83.7 years (SD: 3.7 years).  In the bivariate analysis, there were statistically significant associations between the occurrence of falls and the variables: age, polypharmacy, Parkinson's disease, osteoporosis, dizziness/vertigo and perceived health ( Table 1) Table 2). Rev. Latino-Am. Enfermagem 2017;25:e2900.
In the multiple logistic regression analysis, the  Table 2).
The variables tall cabinet in the kitchen, grab bar in the toilet and switch far from the bathroom door lost significance when entering the multiple model.

Discussion
This is the first population-based, home-based study conducted exclusively with Brazilian older adults aged 80 years or older, investigating the association between falls and extrinsic factors, providing support for identifying risk factors for the prevention of falls. The prevalence of falls was similar to a related study that found a percentage of 43.0% (17) and is in accordance with the international literature, that presents a percentage of 42.0% (12) . Data from the World Health Organization show that 32.0% to 42.0% of the older adults aged 70 and over suffer falls every year (16) .
Older ages showed association with a higher number of falls and an increased risk of the event.
The biological aging process comprises structural and functional changes that progressively accumulate.
These alterations may compromise the performance of motor skills, hinder the individual's adaptation to the environment and predispose them to suffering falls (8) .
Advanced age is closely related to predisposing factors for falls (9) .
Regarding the usage of medication, a higher frequency of falls occurred in the elderly who used four or more medications, which characterizes polypharmacy.
The relationship between the usage of medications and occurrence of falls was statistically significant, since the medications may alter motor responses and cognitive capacity, and cause postural hypotension, somnolence, dizziness and the need to urinate more frequently (12) .
Parkinson's disease and osteoporosis were associated with falls. Parkinson's disease is a chronic and progressive pathology, characterized by the degeneration of neurons and difficulties in balance.

Cognitive decline is indicated as a variable that directly
influences the risk of falls in older adults (18) .
Osteoporosis is strongly related to falls, fractures, and declining functional capacity and quality of life.
Individuals with osteoporosis may present postural alteration, abnormal gait and body imbalance, which may lead to the occurrence of falls (8) . Most older adults in our study reported dizziness/vertigo. These changes are frequent in older adults and are factors that predispose them to the occurrence of falls (19) .  (20) .
Among those who suffered a fall, one-third had a fracture as a consequence, and most of them (34.3%) were fractures of the legs and/or knees. Studies conducted in the community have shown that fractures are more common in the lower limbs (8) . The higher probability of suffering a fracture as a consequence of a fall is due to the high prevalence of comorbidities in this population (17) .
The bathroom, the living room and the bedroom were pointed as the places where the elderly fell more frequently. Likewise, a study carried out in the city of Catanduva, in the state of São Paulo, Brazil, with institutionalized older adults found these same places as the main places of falls (21) . can also support guidelines to subsidize the construction of public policies and health care programs for this population.

Conclusion
The study showed a 46.9% prevalence of falls.
There was an association between falls and the presence