risk factors

by Rein Tideiksaar, PhD

Risk Factors for Falls
Falls are complex events and are caused by a number of factors. These factors include intrinsic factors (such as diseases and medications) and/or extrinsic factors (environmental hazards, for example). The likelihood of falling increases with the number of risk factors a person experiences.

Intrinsic Factors

Previous Falls
A history of falling is the most reliable predictor of future falls among community-based, hospitalized and institution-based elderly. Previous falls are markers for underlying disorders associated with fall risk.

Diseases
Impaired vision (due to cataracts, macular degeneration, and glaucoma). These conditions can lead to a variety of outcomes:

Decrease in dark adaptation (the ability of the eyes to adjust to varying light levels, particularly under conditions of low illumination such as when walking about or visiting the bathroom at night)
Increase in the sensitivity of the eye to glare (common sources of glare include sunlight shining through windows and reflecting off waxed floors or glossy tabletops, and bright light from unshielded light bulbs)
Decrease in visual acuity and contrast sensitivity (this makes the detection of low-contrast objects in the environment difficult and leads to unsafe ambulation)
Decrease in depth perception (this make the visual detection of curb and step edges difficult). In addition, a loss of depth perception makes it difficult to perceive objects in areas of shadows, low illumination or excessive brightness.
Lower and upper extremity impairment (as from arthritis, muscular weakness, etc.). Any impairment of the legs and/or arms can lead to unsteady gait and balance and impaired transfers from beds, chairs, and toilets.
Gait and balance impairment (as in stroke, Parkinson's disease, arthritis, foot disorders, etc.).
Cognitive impairment (dementia, depression, delirium, and denial of mobility limitations, for example). Altered mental status (confusion, disorientation or impaired memory) is one of the most important risk factors for falling. Impaired understanding due to language or cultural differences and educational or literacy problems is associated with fall risk as well.
Bladder dysfunction (frequent urination, nocturia, incontinence and needing assistance with toileting). Elders who report nocturia two or more times during the night are at significant risk of falling.

Medications
Medications are a significant risk factor for falls. The most common drugs associated with fall risk include those that act on the central nervous system, such as sedatives and tranquilizers, and benzodiazepines. Individuals receiving three or more psychoactive drugs are particularly at risk of falling. Other important medications include digoxin, anti-seizure medications, beta blockers, anticoagulants and cardiac medications (diuretics and hypotensives). Drug effects and reactions can affect cognition and balance, thus contributing to falls.

Extrinsic Factors

Environmental factors account for up to one-half of all falls among elders. The risk of environmental hazards contributing to falls is greatest in those individuals with poor ambulation and transfer abilities, which may result in a mismatch between the individual's mobility capabilities and the design of the surrounding environment. For example, individuals with poor gait are at greater risk of balance loss and falls when walking on waxed or slippery floors than those individuals with normal gait.

Likewise, individuals with poor transfers are at greater fall risk when getting up from low-seated chairs than individuals with normal transfer capabilities. Important environmental hazards include:

Low or elevated bed heights
Bed side rails interfering with safe bed exits
Low-seated chairs
Low-seated toilets lacking sufficient grab bar support
Poor lighting
Stairways (lack of hand supports/rails)
Slippery floor surfaces (wet or polished floors, and rugs)
Slippery tub/shower ground surfaces
Bedroom and hallway clutter
Improper walking devices and wheelchairs (inappropriate size and/or use)
Faulty footwear (slippery soles, improper fit)
Poorly maintained walking aids (canes and walkers)
Lack of safety equipment, such as grab bars and other durable medical equipment

Causes of Falling
Falls are often a sign or marker of an underlying acute or chronic medical problem and/or mobility impairment. Consequently, a fall should be viewed as a nonspecific event representative of an underlying problem attributed to either intrinsic or extrinsic factors. For instance, a fall may be due to:

Acute diseases (syncope, arrhythmia, infection, sudden exacerbations of underlying chronic diseases, such as congestive heart failure, etc.)
Effects of acute diseases, such as urinary tract infection which can result in urinary frequency causing an individual to rush to the bathroom, and thereby, exceed their safe limits of mobility
Adverse medication effects (hypotension, delirium, ataxia, etc.)
Chronic diseases affecting gait and balance
Mobility dysfunction resulting from acute and chronic illness, fear of falling and/or injury, and activity restrictions
Hazardous environmental conditions interfering with safe mobility.

About ten percent of falls are due to acute medical problems and ninety percent of falls are due to chronic diseases and associated mobility impairments interfacing with unsafe environments.

Posted October 2005