Falls in Older People

As the aging population increases, falls and fall prevention have received much attention. Falls, both injurious and non-injurious, cause potentially adverse physical, social, and financial consequences. Fall incidents are common in older people, with higher occurrences in individuals aged 65 and above. There has been an increase in fall research and local and national management guidelines, reflecting multidisciplinary professional and public awareness of falls. Falls are complex with many contributing risk factors, such as muscle weakness, impaired postural stability, visual impairment, certain medical conditions and home/environmental hazards. Numerous assessment tools and interventions have been established to prevent fall incidents.

EPIDEMIOLOGY AND FALL CONSEQUENCES
Falls are one of the leading causes of death and injury among older people. Falls occur in more than one-third of adults aged 65 and older annually. Thirty to fifty percent (30 percent - 50 percent) of people aged over 65 fall at least once a year. In 2005, 15,800 people 65 and older died from fall-related injuries. Approximately 1.8 million people 65 and older were treated in emergency departments for nonfatal injuries from falls; of those, 433,000 were hospitalized. The risk of being seriously injured in a fall increases with age. Specifically, individuals aged 85 and above are four to five times more likely to fall than those aged 65 to 74. Consequences of falls include bruises, hip fractures, head trauma and death. Significant psychosocial implications of falls, such as loss of confidence, avoidance of activities, and increased social isolation because of reduced mobility and physical fitness, and an increase in an individual's actual risk of falling. Men are more likely to die from falls. In 2004, the fall fatality rate was 49 percent higher for men than for women after adjusting for age. However, women are 67 percent more likely than men to have a nonfatal fall injury. Ninety-five percent (95 percent) of hip fractures in older women are caused by falls. Individuals aged 75 and above who fall are four to five times more likely to be admitted to a rehabilitation facility for a year and longer. Costs associated with falls are enormous. In 2000, direct medical costs for fatal falls and nonfatal fall injuries were $179 million and $19 billion, respectively.


RISK FACTORS
A fall could be a consequence of interaction among a variety of risk factors. In excess of 400 potential falls associated with risk factors have been reported. For example, osteoarthritis, as an independent risk factor, could lead to a fall as a result of its contribution to muscle weakness and gait abnormalities. Risk factors can be broadly classified into two categories -- namely, intrinsic such as muscle weakness, postural control and certain medical conditions; and extrinsic, environmental hazards.

Intrinsic Factors

Neural Control of Balance
Postural control is a complex motor skill with two main functional goals; namely, postural orientation and postural equilibrium. Postural orientation involves active alignment of the body as it relates to changes in gravity, support surfaces, visual cues and internal resources. Sensory information from somatosensory, vestibular and visual systems are integrated and weighed depending on the goals of the movement task and the environmental context. Postural equilibrium involves the coordination of movement strategies (e.g., ankle, hip and stepping strategy) to stabilize the center of body mass during self-initiated or externally triggered disturbances of stability. Important resources required for postural stability and orientation include biomechanical constraints, movement strategies, sensory strategies, orientation in space, control of dynamics and cognitive processing. The most important biomechanical constraints on balance are the size and quality of the base of support and controlling the body center of mass (CoM) related to its base of support with the central nervous system (CNS) having an internal representation of the stability limits of the body. Individuals with basal ganglia disorders like Parkinson disease have postural instability due to abnormal representation of stability limits in CNS. Movement strategies, ankle, hip,and stepping are used to maintain postural stability. Older individuals with high risk of falls tend to use stepping, reaching and hip strategies. Selected strategies depend on intention, experience and expectation. Integration of the somatosensory, visual and vestibular systems are important to interpret complex sensory environment. The sensory information is weighed depending on environmental contexts. Individuals with a loss of at least one sensory system, e.g., neuropathy (somatosensory loss) are limited in their re-weight postural sensory, resulting in higher risk of falls. Body orientation in space related to gravity, the support surface, visual surround and internal references is controlled by the nervous system. Individuals with inaccurate internal representation of verticality will have postural instability due to problems with body alignment with gravity. Complex control of body CoM movement is important for dynamic balance. Older people with fall risks tend to demonstrate larger-than-normal lateral excursion of the body CoM and more irregular lateral foot placements. Cognitive processing is another requirement for postural control. Postural control and cognitive processing share the same cognitive resources. Individuals with cognitive impairment are at risk of falling as a consequence of their using a limited cognitive resource to control posture. Older people who have balance disorders are found to have multiple fall risk related impairments, such as multi-sensory loss, weakness, orthopaedic constraints and cognitive impairments. It is important, however, that these impairments do not directly cause functional loss. For example, some people with a particular impairment have much better function than others depending upon the type of impairment and the strategies used to compensate for the impairment. Thus, impairments to different systems result in different, context-specific instabilities. It is recommended that a comprehensive evaluation by a clinician skilled at systematically evaluating impairments and strategies underlying functional performance in postural stability is necessary for optimal balance rehabilitation and fall prevention.

Foot and Ankle Characteristics
A study by Menz et al showed that foot and ankle characteristics significantly contribute to balance and functional ability in older people. Plantar tactile sensitivity, ankle flexibility, the presence of lesser toe deformity and the sensitivity of hallux valgus for foot and ankle characteristics demonstrated the most consistent associations with balance and functional test scores. There is an association between plantar sensation and standing balance; for example, increase in postural sway was found in individuals with peripheral neuropathy. Toe muscle function is very important to maintain balance in older people, e.g., older people demonstrate greater pressure with their toes than do younger ones when standing while attempting to intensify sensory information to maintain balance. From the sensorimotor aspect, strength and reaction time exhibited the strongest correlations with balance and functional performance. Interventions that may improve balance in older people include augmentation of tactile sensory information from the sole of the foot, increase ankle ROM (range of motion) and increase strength of toe plantarflexor muscles.

Biomechanics of Slips and Falls
A study of the aging effects on the process of slips and falls using biomechanical parameters showed that there were no significant differences in the slip initiation process regardless of the influencing factors such as step length, walking velocity and heel contact velocity, among different age groups. On the other hand, during the slip and fall detection and recovery stage, older adults were more likely to fall as a result of a delayed fall response selection processes. Older adults exhibited longer motor control times and a slower and less effective recovery process. The study suggested that recovery from a slip is associated with lower extremity muscle strength and sensory integrity.

Muscle Weakness
As an independent risk factor, muscle weakness is closely linked with gait and balance abnormalities in older people. In one systematic review and meta-analysis of muscle weakness and falls in older adults, the researchers concluded that muscle strength (especially that of lower extremity) is an important risk factor for falls and should be assessed and treated in older adults.

Visual Impairment
Vision is important for stabilizing balance. Visual feedback provides the nervous system with continually updated information regarding the position and movements of body segments in relation to each other and the environment. Postural sway increases by 20 percent to 70 percent when people stand with their eyes closed. Accurate perception of visual stimuli and depth is important to provide a visual reference frame for body stabilization relative to its surroundings. Based on a review study by Lord, visual acuity might not be associated with increasing risk for falls. However, older people with a loss of edge-contrast sensitivity are predisposed to trip over obstacles within the home and outdoor hazards, e.g., steps, curbs, and pavement cracks and misalignments. Reduced depth perception also is found to be strongly associated with falls. The author suggested that the ability to negotiate and avoid obstacles and hazards in the environment depended on the ability to judge distances accurately and perceive spatial relationships. Another factor adding to the risk of falls is wearing multifocal glasses. With multifocal glasses, older people view the environment through their lower lenses and that impairs the important visual capabilities (contrast sensitivity and depth perception) for detecting environmental hazards, particularly in unfamiliar environments. Simple interventions recommended included regular eye examinations, use of correct prescription glasses, cataract surgery, the removal of tripping hazards in the home and use of single-lens distance glasses in higher-risk situations (e.g., negotiating stairs, walking outside the home).

Neurological Diseases
Fall prevalence is high among individuals with neurological problems. One study investigated the prevalence, risk factors and etiology of falls in neurological inpatients. The result showed that one-third of inpatients in the neurological department fell twice as often as those in an age-matched population living in the community. Fifty-five percent of the falls was directly related to a gait disturbance in neurological inpatients. Postural disturbance and sensory impairment (a typical symptom of polyneuropathy) was another factor found that strongly correlated with falls. These impairments are typical in neurological patients. Disease-related risk factors for falls included Parkinson disease (PD), syncope, polyneuropathy, spinal disorders, motor neuron disease and multiple sclerosis. Impairments in the sensory motor system are commonly found in patients with these neurological diseases. The number of falls and injuries were found very high among individuals with PD. Freezing episodes, difficulties with turns and problems getting up from a chair were identified as indicators of high fall risk in PD patients.

Syncope and Neurocardiovascular Factors
Syncopal episodes have been found to be related to falls, particularly in patients where there is no clear explanation for fall circumstances such as poor recall of falls, lack of witness account and the demonstration of amnesia from loss of consciousness. Syncope, the mechanism by which cardiovascular abnormalities is a symptom, defined as a transient, self-limited loss of consciousness, usually leads to falls. Syncope is common among older people (aged 70 and up) with increased fall incidences. Factors including age-associated physiological changes in heart rate, blood pressure, cerebral blood flow, baroreflex sensitivity and intravascular volume regulation, combined with comorbid conditions and concurrent medications, contribute to a higher incidence of syncope in the older population. Frequent causes of syncopal falls in older people include orthostatic hypotension, carotid sinus syndrome, neutrally mediated syncope and cardiac arrhythmias. Orthostatic hypotension occurs between six percent (in community-dwelling older people) to 33 percent (in hospital inpatients). It is responsible for up to 36 percent of syncope in older individuals. Orthostatic hypotension is defined as “a fall in systolic blood pressure by at least 20 or more or a drop in diastolic blood pressure by at least 10 mmHg on standing.” In the absence of identifiable precipitating factors, it occurs when the autonomic nervous system fails to respond adequately to the upright position by vasoconstrictor mechanisms, resulting in a reduction in blood pressure of sufficient magnitude to give rise to the symptoms. Identifiable causes of orthostatic hypotension include culprit medications, primary autonomic failure, secondary autonomic failure (diabetes), PD or multisystem atrophy. Cardioinhibitory carotid sinus syndrome is identified as a potential cause of unexplained falls and is accounted for up to 20 percent of syncope in elderly people. Carotid sinus syndrome rarely occurs before age 40. The syndrome is diagnosed in patients who are found to have an abnormal response to carotid sinus massage (carotid sinus hypersensitivity) and an otherwise negative investigational workup for syncope. One study related to intervention in the form of a dual-chamber pacemaker for subjects with unexplained or recurrent falls who had cardioinhibitory carotid sinus syndrome, was found to associate with a significant reduction in the rate of falls as well as of syncope.

Neutrally Mediated Syncope
Neutrally mediated syncope accounts for up to 15 percent of syncope individuals. In older individuals, nonclassical vasovagal syncope (episode without clear triggering events or premonitory signs) is more common, making these individuals more susceptible to falls. The cause is also found to be related to prescription of cardiovascular medications. Situation syncope with micturition and gastrointestinal stimulation (swallowing, defecation and visceral pain) is very common among older people.

Cardiac Arrhythmias
Up to 20 percent of syncope in older individuals is due to cardiac arrhythmias. Both bradyarrhythmias and tachyarrhythmias potentially trigger falls through reduction in cardiac output leading to hypotension and collapse.

Other Chronic Diseases
Based on a study by Lawlor et al, circulatory disease, chronic obstructive pulmonary disease, depression and arthritis are associated with higher odds of falling, even with adjustment for drug use and other potential confounding factors. The authors also investigated participants’ drug use and concluded that the risk of falls was higher for chronic diseases and multiple pathology (32 percent) than for polypharmacy (two percent - five percent). The recommended public health strategy for preventing falls in elderly persons was to target prevention and control of chronic disease rather than polypharmacy.

Extrinsic Factors

Physical Environment
Environmental hazards contribute to half of all falls in older people. Based on previous studies, 50 percent to 70 percent of falls happen in or around the home and 40 percent to 60 percent of falls are due to environmental hazards. Poor lighting, floor surfaces, stairs, objects on pathway, poorly designed furniture, placement of furniture and toilet design are most common hazards found in older adults’ homes. In one study, dim lighting (31.8 percent), slippery floor or floor with obstacles (18.2 percent), out of reach storage area (14.6 percent), carpeting or rug without nonskid backing (14.6 percent), and loose or nonexistent grab bars or handrails (13.0 percent) were major potential home environmental hazards. Based on another study, 80 percent of homes in community-dwelling individuals over 70 years of age had at least one hazard, and 39 percent had more than five hazards. The bathroom was identified as the most hazardous room, with 66 percent of bathrooms having at least one hazard. Another potential hazard found was mismatches between the home environment and physical capabilities. For example, low-lying chairs were more prevalent in homes of people having difficulty in transferring; whereas obstructed pathways were more prevalent in homes of people having gait problems. The studies on the effect of environmental hazards on frail versus vigorous older adults have shown that environmental hazards were more likely to be associated with falls in vigorous rather than frail individuals. A frail older person generally fell at home and during routine nondisplacement daily activities, such as standing or turning. On the other hand, vigorous individuals tended to fall while away from home, on stairs, in the presence of environmental hazards or during displacement activities such as walking or climbing. One study comparing falls and the presence of home hazards in vigorous and frail older people concluded that both variables were not strongly associated. A study examining interaction between behavioral and environmental factors on falls concluded that participants without preceding falls had a four-fold risk of falls in the presence of six or seven home hazards compared with those people without home hazards. In addition, there was no increased risk of falls with increasing numbers of home hazards in participants with preceding falls. The authors explained that the difference could be a result of behavioral differences between recurrent fallers (more cautious) and non-fallers (less cautious). Another study found that 63 percent of the falls were due to risk-taking behaviors, such as not being careful or alert, not looking where one was going and being in a hurry. Based on a study by Feldman and Chaudhury, falls were reduced by 60 percent after implementing home modification intervention only. The interventions included a free home safety inspection and simple home modification such as grab rails and nonslip floor surfaces. One study on adherence to home-modification interventions found that the intervention resulted in a small reduction in the mean number of hazards per house.

One reason was that older individuals are usually emotionally attached to their environments, and most do not acknowledge the need for interventions to prevent falls. Another study found that of the 419 home modifications that had been recommended in the 121 homes, only 216 (52 percent) were met with partial or complete adherence when revisited after 12 months. In addition, the only significant predictors of adherence were a belief that home modifications can prevent falls and having help from relatives at home.

Polypharmacy
Numerous studies supported that the use of four or more regular medications has been associated with an increased risk of falls. Psychotropic drugs associated with falls includes benzodiazepines, antidepressants, neuroleptics and anti-convulsants. Older people are especially vulnerable to the neurological side effects of these medications because of the changes in their pharmacokinetics and pharmacodynamics related to aging. Landi et al investigated current use of different classes of psychotopic medications (including antipsychotic agents, benzodiazepines, nonbenzodiazepine sedative-hypnotics and antidepressants) and the risks of falls. The result showed that users of psychotropic drugs had an increased risk of fall of nearly 47 percent after adjusting for all potential confounders. Users of atypical antipsychotic drugs also had an increased risk of falling at least once compared with nonusers. The risk of falls increased among benzodiazepine users regardless of the use of long elimination half-life or short elimination half-life. Compared to nonusers, patients taking antidepressants did not show a higher risk of falling. The authors concluded that minimizing the use of CNS active medications may decrease the risk for falling. Medication modification has been effective in fall reduction and also cost effective. A study by van der Velde N et al on geriatric outpatients showed that after adjustment for confounders, drug withdrawal resulted in a falls risk reduction of 0.89 (with a 95 percent confidence interval of 0.33 to 0.98) per patient compared with the nonwithdrawal group. Net cost savings were €1691 per patient in the cohort or €491 per prevented fall. There are multiple risk factors in many individuals with a history of falls.The risk of falling is increased by synergism of risk factors. An older person without identifiable factors has an eight percent risk of falling compared to 78 percent in those with fouror more risk factors.

RISK ASSESSMENT TOOLS
Fall-risk factors are multiple. There are several methods and tools devised to assess balance and risk of falls. The American and British Geriatrics Societies recommended the Timed Up and Go Test (TUGT) as a screening tool for identifying older people at increased risk of falls. The TUGT, an indicator of ‘basic mobility,’ measures the time required for a person to rise from a chair, walk three meters, return to the chair and sit down. The tool was found to be significantly correlated with slow gait speed, low Berg balance and Barthel Index scores. Some studies investigate the relationship between TUGT performance and falls in community-dwelling people. For example, a study by Shumway-Cook et al found that a TUGT cut-point of 14 seconds significantly discriminated between the faller and non-faller groups. In this study, 13/15 subjects from both groups were correctly classified using this criterion, providing sensitivity and specificity for identifying fall outcome of 87 percent. In another example using 157 subjects, the TUGT had very high sensitivity with 98 percent of the 109 fallers being correctly classified, but considerably lower sensitivity, with only 15 percent of the 48 non-fallers being correctly classified. The TUGT, although simple and easy to administer, cannot provide detailed information regarding the impairments in physiological domains that contribute to falls risk and therefore provides little in the way of information about how to target intervention strategies. The Physiological Profile Assessment (PPA) provides objective data on the relative contribution of vision, proprioception, muscle strength, reaction time and postural stability to fall risk, and is useful in identifying likely interventions to reduce falls risk. The PPA is a good predictor of those at risk of future recurrent falls; however, it requires specific equipment. Another comprehensive clinical assessment of falls risk to identify remediable causes of gait and balance problems is the performance-orientated assessment of mobility devised by Tinetti. This tool assesses gait and balance refined and applied to different study populations. It contains a nine-point gait score and a 13-point balance score for community-living older people. Besides the assessment tools mentioned, one study on the optimal sequence and selection of screening test items to predict fall risk recommended collecting data and assessment regarding the number of falls in the last year, frequency of difficulty balancing while walking, a four meter walking speed test, body mass index and a test of knee extensor strength in identifying risk of falls in older people.

FALL PREVENTION INTERVENTIONS
Any successful interventions in reducing fall rates, fall-related injury or the psychosocial restrictions linked with a fear of falling could improve quality of life for older people and reduce the expenses related to fall and fall injury. Numerous studies have investigated the efficacy of fall intervention and prevention. Fall risks are multifactorial; thus study outcomes need to be interpreted with caution, especially if only one outcome measure is reported. In general, interventions can be separated into single and multifactorial.

Exercise
Exercise interventions have been mostly widely studied of all the single interventions assessed in falls prevention. A study by Campbell and colleagues was to investigate the efficacy of a home-based exercise program in women aged 80 and older. The subjects were monitored on falls, injuries, and compliance with the exercise program over two years. This study concluded that an individualized home strengthening and balance retraining exercise program was effective in fall reduction. For those who keep exercising, the benefit continues over a two-year period. Individuals who were more likely to continue exercising were more physically active, had experienced a previous fall and remained confident about not falling. The authors recommended a minimum of ongoing contact with the therapists with a six monthly follow-up home visits for program modification, to encourage compliance and enthusiasm for the benefits of the program.

This finding also was supported by another study by Campbell et al. This study was to investigate the effectiveness of an individual home-based program of strength and balance retraining exercises in improved physical function and in reducing falls and injuries in women 80 years and older. The authors found that after six months, balance and performance of the subjects in the exercise group in the chair stand test had improved compared with the control group. After one year follow up, there were 152 falls in the control group and 88 falls in the exercise group.

Another type of exercise “Tai Chi,” becoming a popular choice of exercise, has been receiving increasing research attention, mainly because Tai Chi is supposed to be beneficial for improving flexibility and balance through its unique capacity to enhance lower extremity strength and improve postural stability. Based on the results of many studies, Tai Chi has been shown to reduce the risk for falls and fear of falling. For example, in a study by Lietalon on Tai Chi and fall reductions in older adults concluded that a three times per week, six-month Tai Chi program was effective in decreasing the number of falls, the risk for falling and the fear of falling. The program helped improve functional balance and physical performance in physically inactive persons aged 70 years or older. In summary, exercise as a single intervention has been supported by many studies to be effective in reducing fall rate, particularly the program that is individualized and prolonged in duration.

Fall Prevention Programs
In addition to single intervention, multicomponent fall prevention programs and community program guidelines are proved to be effective and supported by many studies. This seems logical since most falls result from multiple risk factors. An article by Tinetti on preventing falls in elderly persons recommended that all patients aged 75 years or older (or 70 years or older, if they are known to be at risk for falling) should be asked about their fall history, questioned about the circumstances of the falls and examined the potential risk factors. Since the majority of falls result from interactions between long-term or short-term predisposing factors and short-term precipitating factors in a person’s environment, multifactorial assessment and intervention is effectively reducing the fall rate. However multifactorial assessments that are not linked to targeted interventions have been ineffective in preventing falls. Single-intervention strategies also can be proved effective among elderly persons if there is the presence of a known risk factor or a history of falls. These interventions include professionally supervised balance and gait training and muscle-strengthening exercises, gradual discontinuation of psychotropic medications and modification of hazards in the home.

In addition to a fall prevention individual program, a community program can be effective to a high proportion of the elderly population at risk. In general, an individual program requires comprehensive patient assessment and diagnosis. A multidisciplinary team provides individual treatment based on the assessment. In order to reach more people at risk, community or public health programs are less expensive individually and staff intensive. The programs are commonly based on a simple assessment, delivered by a single health professional. One study was to investigate the efficacy of multiple components compared to single strategies in community-based fall prevention. The result showed that the delivery of single factor intervention to a selected population was as effective in reducing falls as delivering multifactorial interventions to at risk community populations. Effective fall prevention interventions decreased the number of falls by almost a third regardless of single or multiple components. Successful single interventions were the ones that addressed the risk factor that accounted for a large proportion of the falls risk. Multifactorial interventions were not successful if they caused confusion, or lead to more change than the older person was willing to accept. Based on the result, the authors recommended that targeted single interventions are the most acceptable, cost effective and easily instituted method of achieving fall reduction in the community.

SUMMARY
Falls and fall-related injuries are common problems in older people aged 65 years and older, with significant potential physical and psychosocial consequences. Falls mostly result from interactions among multiple risk factors broadly categorized into intrinsic and extrinsic factors. Intrinsic factors include muscle weakness, impaired neural control of balance, visual impairment and certain health conditions/diseases. Extrinsic factors include environmental hazards and polypharmacy. Several tools have been found to be effective to assess fall risk such as the Tinetti, Timed-Up-and-Go Test and the Physiological Profile Assessments. Intervention for fall prevention can be single or multifactorial. Effective interventions are ones that target and address the minimization or eliminate risk factors. Strengthening and balance retraining exercises such as Tai Chi have proven to be effective in fall reduction. Individualized comprehensive assessment for risk factors and correspondent intervention is very important in preventing falls in older people.


Powanusron, Alexis R., and Jennifer M. Bottomley. "Falls in Older People." Gerinotes Vol. 17,
No.2 (2010)