Falls are the leading cause of injury among older adults and the risk of falls and subsequent fall-related injury increases with age [1]. Falls are not only associated with morbidity and mortality in older populations, but are also related to immobility, decreased quality of life, fear of falling, functional dependency, early admission to long-term care facilities, and increased medical costs [2]. Accordingly, identifying older adults at an increased risk of falls and effective fall prevention interventions have the potential to reduce fall risk among older individuals, as well as fall-related disability and medical costs [3].

In the United States, around one-third of people aged 65 years or older living in the community fall every year, and about half of those who fall do so repeatedly. Although not all falls lead to injury, about 10% result in a major injury such as a fracture, serious soft tissue injury, or traumatic brain injury requiring medical attention [4]. In 2012, 2.4 million nonfatal falls among older adults were treated in emergency departments and more than 722,000 of these patients were hospitalized [5]. Accordingly, the direct medical costs of falls, adjusted for inflation, is estimated at $30 billion [6].

The incidence of falls among Chinese older people is approximately half of that among Caucasian populations. A systematic literature review of studies conducted in China, Hong Kong, Singapore, and Taiwan revealed that the annual fall rate ranges from 14.7% to 34% (median, 18%). In four prospective studies, injuries were reported by 60% to 75% of those reporting falls, with fractures accounting for 6% to 8% of all injuries [7].

Few studies have explored the prevalence and medical burden of falls among Korean older adults. One study of 351 individuals aged 65 years or older found that 42% reported at least one episode of falling in the previous 12 months, 38% of whom required either the attention of a physician or hospitalization [8]. In another study, 13% of 828 community-dwelling older Korean adults experienced falls during the last year [9]. Additionally, a questionnaire-based interview survey of 2,295 older adults living in rural communities revealed that 32% had suffered from fall-related injuries during the previous year. The direct costs of these injuries were calculated to be 596,466,000 won (US $1 = ￦1,140) and the total socioeconomic costs were estimated to be 1,054,547,000 won. When the above calculated socioeconomic cost for the 2,295 subjects is applied to the 1,067,262 Korean rural older adults in 2009, the socioeconomic costs due to fall-related injuries can be estimated as 343,614,988,000 won [10]. Accordingly, falls are one of the most common, and most important, medical problems among Korean older adults.

Previous studies have identified independent risk factors for falls or fall-related injuries. Comprehensive management of identified risks has a clinical benefit in preventing falls [11]. The greatest risk factors for falls include previous falls, strength, gait and balance impairments, visual impairment, arthritis, disability, depression, and cognitive impairment. Additionally, polypharmacy, anti-hypertension or psychotropic medications, arrhythmia, and Parkinson’s disease are reportedly risk factors for falls [12-16]. The risk of falls increases with the number of risk factors, and comprehensive multifactorial assessment and risk factor interventions can decrease the risk of falls and improve the health status of older adults [17,18].

Primary care physicians should be able to identify community-dwelling older adults at a high risk for falls. Previous studies have identified independent risk factors of falls or fall-related injuries, and fall risk increases as the number of risk factors increase. However, it is challenging to translate these findings into a strategy for primary care physicians to reliably identify older adults that require fall interventions.

Screening for falls is aimed at preventing or reducing fall risk. Any positive answer to the screening questions puts the person screened in a high-risk group that warrants further multifactorial fall risk evaluation. A history of falling is most commonly used to identify an increased risk for future falling and has generally been considered concurrently or sequentially with other key risk factors, particularly gait and balance. Previous studies confirmed that fall history is the most common risk factor other than age.

Furthermore, it is simple to obtain information regarding fall history. The definition of fall history varies, with a history of at least one fall during the previous 12 months or a history of more serious falls that required medical attention. Gait and balance deficits should be evaluated in older individuals reporting a single fall as a screen for identifying individuals who may benefit from a multifactorial fall risk assessment. Older adults at higher risk of falling, as identified by screening, should be assessed for known risk factors.

According to the National Institute for Health and Care Excellence (NICE) guidelines, older people in contact with healthcare professionals should be asked routinely whether they have fallen in the past year and asked about the frequency, context, and characteristics of the falls. Older people reporting a fall or those considered at risk of falling should be observed for balance and gait deficits and considered for their ability to benefit from interventions to improve strength and balance [21].

Although the United States Preventive Services Task Force did not find evidence for frequent brief falls risk assessments, they recommended that primary care physicians could consider the following factors to identify older adults at an increased risk of falls: a history of falls, a history of mobility problems, and poor performance on the timed Get-Up-and-Go test [22].

In contrast, the American Geriatrics Society/British Geriatrics Society (AGS/BGS) guidelines recommend that all older adults under the care of a health professional should be asked at least once a year about falls, frequency of falling, and difficulties in gait or balance [23]. For individuals who screen positive for falls or fall risk, evaluation of balance and gait should be part of the multifactorial fall risk assessment. Commonly used tests of gait or balance include the Timed Up and Go test, the Berg Balance Scale, and the Performance-Oriented Mobility Assessment.

Accordingly, despite the controversy about the frequency of falls risk assessment and tools for gait and mobility evaluation, we recommend that primary care physicians should be able to identify older adults at an increased risk for falls by asking about a history of falls and performing gait or balance tests such as the Timed Up and Go test, the Berg Balance Scale, and the Performance-Oriented Mobility Assessment (Fig. 3).

Comprehensive multifactorial fall assessments and interventions include assessment of multiple risk factors for falls and providing medical and social care to address factors identified during the assessment. A multifactorial fall risk assessment followed by interventions to modify any identified risk factors is considered a highly effective strategy to reduce falls among older adults, as this can address the risk factors of falls, and is expected to lead to more reductions in fall risks than dealing with each risk factor separately. Multifactorial fall risk assessments are a comprehensive geriatric assessment or falls-focused assessment, generally including two or more of the following assessments: vision, gait, mobility, muscle strength, medication use, cognitive impairment, orthostatic hypotension, and environmental risks. Multifactorial assessments should be performed by a healthcare professional with appropriate skills and experience. A multifactorial fall risk assessment should be performed for community-dwelling older persons who report recurrent (≥ 2) falls, difficulties with gait or balance, or who seek medical attention or present to the emergency department because of a fall [23].

According to the NICE guidelines, multifactorial assessments should include fall history, assessment of gait, balance, mobility, and muscle weakness, assessment of osteoporosis risk, assessment of the older person’s perceived functional ability and fear of falling, assessment of visual impairment, assessment of cognitive impairment and neurological examination, assessment of urinary incontinence, assessment of home hazards, cardiovascular examination, and medication review.

According to the AGS/BGS guidelines, multifactorial fall risk assessments can identify factors associated with the increased risk of falling and the most appropriate interventions. They list the following components of multifactorial fall risk assessments; medication, visual acuity, neurological impairment, muscle strength, heart rate and rhythm, postural hypotension, feet and footwear, and environmental hazards [23].

Some research has reported that some combination of multifactorial fall risk assessments and interventions in a select population can provide benefits. However, the characteristics of a comprehensive multifactorial assessment and intervention have not been clearly defined, and different approaches to classification may lead to different results. Additionally, there has been statistical heterogeneity and uncertainty regarding the optimal combination of multifactorial risk assessments. Overall, these comprehensive programs seem to be complicated in a primary care setting. The USPSTF does not recommend automatically performing an in-depth multifactorial risk assessment in conjunction with comprehensive management of identified risks to prevent falls in community-dwelling older adults because the likelihood of benefit is expected to be small [25]. They recommend that clinicians should consider the balance of benefits and harms based on the circumstances of prior falls, medical comorbid conditions, and patient values in determining whether this service is appropriate in individual cases.

However, for older adults at an increased risk for falls based on screening tests such as fall history and abnormalities in gait or balance tests, multifactorial fall risk assessments and interventions can decrease the risk of falls and improve health status. Therefore, we recommend that primary care physicians perform multifactorial fall risk assessments to identify multiple risk factors for falls and improve the health status of older adults at an increased risk for falls using screening tests such as fall history and abnormalities in gait or balance tests (Fig. 3).

Vitamin D is known to play an important role in bone tissue. The effects of vitamin D on intestinal absorption of calcium and bone mineralization increase bone mineral density and decrease the risk of fracture. Several lines of clinical evidence suggest the existence of a link between vitamin D and muscle or nerve function [26-28]. Vitamin D deficiency or insufficiency may result in metabolic bone disease, may increase the risk of fall, and is associated with increased risk for several health conditions including cardiometabolic diseases, infection, and autoimmune diseases [29,30]. A major reason for vitamin D deficiency is the lack of cutaneous production of vitamin D by ultraviolet due to an indoor lifestyle. Thus, vitamin D deficiency is very common in Western countries, as well as Korea [31]. Aging is also an important cause of vitamin D deficiency. Vitamin D plays an important role in elderly people at increased risk of fracture [32]. Therefore, determining whether to replenish vitamin D in community-dwelling older people to reduce falls or fractures is important. Many studies have analyzed the effect of vitamin D on falls and fractures in the relatively healthy elderly, but the results have been inconsistent. This could be due to potential confounders such as the characteristics of participants, vitamin D alone or the combination of vitamin D and calcium, the dosage and form of vitamin D, treatment period of vitamin D, or the baseline level of vitamin D. Thus, each set of guidelines includes slightly different recommendations. The U.S. Preventive Services Task Force recommends vitamin D supplementation to prevent falls in community-dwelling adults aged 65 years or older at an increased risk for fall or older persons with proven or suspected vitamin D deficiency [22,23]. In contrast, the NICE has made no firm recommendations about the use of vitamin D for this indication, because of uncertainty regarding the relative contribution to fracture reduction and the dose and route of administration required [21].

The recommendations in these guidelines are derived from meta-analysis of randomized controlled trials [25,33]. A meta-analysis of 14 trials (n = 28,135) that evaluated the efficacy of fall prevention by supplementation with vitamin D, either alone or with calcium co-supplementation, did not reveal statistically significant differences in rate of falls, risk of falling, or risk of fracture. Analysis limited to the elderly at higher fall risk revealed no significant differences in either rate of falls or risk of falls. However, vitamin D supplementation to older people with lower vitamin D levels significantly reduced the rate of falls (relative risk [RR], 0.57; 95% confidence interval [CI], 0.37 to 0.89) and risk of falls (RR, 0.70; 95% CI, 0.56 to 0.87).

The effects of vitamin D on fractures differ depending on the characteristics of the participants and co-supplementation with calcium. Vitamin D alone produced no statistically significant reduction in hip fracture or any fracture. In contrast, administration of both vitamin D and calcium was associated with a significant reduction in the incidence of hip fracture (RR, 0.84; 95% CI, 0.74 to 0.96), non-vertebral fracture (RR, 0.86; 95% CI, 0.78 to 0.96), and any fracture (RR, 0.95; 95% CI, 0.90 to 0.99). In a subgroup analysis by residential status, these effects for fracture reduction were observed only in institutional residents, and were not significant in community-dwelling older people (hip fracture: RR, 0.91; 95% CI, 0.77 to 1.09; any fracture: RR, 0.96; 95% CI, 0.91 to 1.01).

Adverse effects were not affected by vitamin D alone. However, there was a small increase in the risk of gastrointestinal symptoms (RR, 1.05; 95% CI, 1.01 to 1.09) and a significant increase in renal calculi and renal disease (RR, 1.17; 95% CI, 1.03 to 1.34), especially for vitamin D plus calcium supplementation. Hypercalcemia was more common in people receiving calcitriol, a vitamin D analogue, compared to those receiving placebo or control (RR, 4.41; 95% CI, 2.14 to 9.09). Other systemic reviews have found an increased association of cardiovascular disease with calcium and/or vitamin D supplementation, particularly in people with a higher dietary calcium intake [34]. However, this association remains controversial. Additionally, it should be considered that daily calcium intake in the Korean population is very low (511.0 ± 7.0 mg) compared to that of participants enrolled in these studies [35].

In conclusion, routine supplementation of vitamin D for fall and fracture prevention for community-dwelling healthy older people is not recommended. However, vitamin D supplementation for elderly people who have lower vitamin D levels may prevent falls. Combined vitamin D and calcium supplementation may prevent fractures in elderly people at an increased risk of fall or fracture. A small but significant increase in gastrointestinal symptoms and renal disease is associated with vitamin D and/or calcium. Therefore, supplementation with vitamin D and/or calcium for older people living in the community should be individualized.

Elderly residing in long-term care settings are at high risk for falls and fracture and are frequently deficient in vitamin D. Effective important interventions are required to reduce falls in this specific high-risk group.

Two trials were conducted: oral vitamin D3 plus calcium or oral vitamin D2 plus calcium versus a control group supplied with calcium. These two trial results both revealed a statistically significant reduction in the rate of falls [36,37]. However, another trial involving oral vitamin D3 (800 IU plus calcium 1,200 mg vs. matching placebo control group) revealed no significant reduction in fall risk [38]. After hospital discharge, neither vitamin D supplementation nor a home-based program of quadriceps resistance exercise improved the risk of fall compared to a control group, but patients in the exercise group were at an increased risk of musculoskeletal injury [39]. An intervention group (oral vitamin D 800 IU plus calcium 1,200 mg) was compared with a control group (calcium 1,200 mg). Although there were fewer falls in the vitamin D group, neither the mean number of falls or time to first fall differed between groups [40]. Elderly people residing in long-term care settings were randomly assigned to receive one of four doses of vitamin D (200, 400, 600, 800 IU) or a placebo control for 5 months. The highest vitamin D group (800 IU) had fewer fallers and a lower incidence rate of falls (72%) than the placebo control group [41]. In vitamin D2 (2.5 mg) or control groups living in care homes, no significant reductions in risk of falls or fractures were observed [42]. The effects of multivitamin supplementation, which included oral vitamin D3 400 IU and calcium 360 mg, were investigated for 6 months. There was a statistically significant reduction in rate of falls, but not in risk of falls [43].

According to the AGS/BGS Clinical Practice Guideline for Prevention of Falls in Older Persons (2010), vitamin D supplements of at least 800 IU daily should be provided to elderly people residing in long-term care settings with proven or suspected vitamin D insufficiency. Additionally, vitamin D supplements of at least 800 IU daily should be considered for elderly people residing in long-term care settings who have gait or balance disorders or who are at high risk for falls [23].

Elderly people who have healthy living habits, avoid sedentary lifestyles, and undergo physical exercise such as walking and other muscle exercises often maintain their health and have an independent daily life.

Falls may cause fractures, which can make it impossible for elderly people to live independently. Therefore, many studies have focused on fall prevention, including the benefits of physical exercise in improving the functional capacity of frail elderly people. Exercise programs tailored to this population are known to be effective [44].

Grahn Kronhed et al. [45] compared the fall incidence rate between two groups of people who engaged in regular exercise or did not engage in regular exercise for a period of 1 year in 2009. The regular exercise group had an average fall incidence of 0.6, whereas the non-exercise group had an average fall incidence of 0.8, and the difference between the two groups was statistically significant. In 2010, Clemson et al. [46] reported that those who regularly performed balance exercises and muscle strengthening had a significantly lower fall rate than those who did not. One group of elderly people living in the community performed exercises for 30 to 90 minutes with one 10-minute break two to three times every week. This group had more fall prevention effects than a control group [47]. One study investigated fall incidence rates among those who engage in multiple forms of exercise (muscle strengthening, balance training, endurance training, and cooperation training) compared to rates among those who do not exercise, and reported that those who engaged in multiple exercises had a significantly lower fall incidence rate. The multiple exercises improved the functional indexes of the physically weak elderly [48]. Cadore et al. [49] performed a meta-analysis of 79 studies, and found that elderly people who engage in muscle strength or endurance exercises two to three times every week have a significantly lower fall incidence rate than those who do not. Regular exercise performed at home is also effective in preventing falls [50].

The fall prevention guidelines proposed by the US/UK Geriatrics Society in 2010 strongly recommend that regular and multi-layered exercises be included in fall prevention programs for the elderly [23]. The NICE guidelines recommend muscle strength and balance exercises to prevent falls among elderly people living in local communities, especially those who have experienced repeated falls, and suggested that the exercise be ordered and managed by experts [21]. USPSTF suggests that fall risk can be reduced when exercise and physical therapy are applied to high fall-risk groups of elderly patients living in local communities, and reported that this can lead to a 13% decrease in falls [22].

In conclusion, regular exercise is required to prevent falls among community-dwelling older adults.

Regular exercise can prevent falls among community-dwelling elderly. Exercise among community-dwelling elderly is classified as group-based exercise or homebased exercise. Home-based exercise has advantages such as being less expensive and allowing long-term performance. Regular exercise in home-based programs improves physical function, prevents falls, maintains bone mineral density, and is feasible within daily life. Strengthening exercises and balance training in homebased exercise decreases the risk of fall [51,52]. However, home-based programs also have limitations in terms of lower compliance and being less effective than groupbased exercise [53,54].

Static and dynamic balancing exercises can be used to improve balance among community-dwelling elderly. Balance exercises may include sit-to-stands, tandem standing, tandem gaiting, unipedal standing, knee bends, change in direction, catching/throwing a ball, and tai-chi [48,55-58].

Strengthening exercises may include ankle cuff weights [57], thera bands [59], and various resistance exercises [60]. They may also include walking, exercise on stationary cycles, and knee and hip extensions performed with a oneleg press in a sitting position. Aerobic and resistive exercises include hip abduction and extension in a standing position [61]. The appropriate amount and type of exercise depends on individual health status. In conclusion, community-dwelling elderly persons at high risk of falling should undergo balance training, strengthening exercises, aerobic exercises, and/or resistance exercises.