Falls prevention in the elderly - common causes and risk assessment

Chung-Tai Sy 施鍾泰

HK Pract 2005;27:103-107

Summary

Falls are common in the elderly; it is often associated with significant morbidity, mortality and admissions to institutions. When a multi-factorial fall evaluation is coupled with intervention of the modifiable risk factors, the likelihood of future falls in an elderly person can be reduced. All elderly persons should be asked for the history of falls at least once a year. For those patients with history of fall, history of recurrent falls or problems of mobility and instability, they should be referred to a clinician or specialist familiar with comprehensive falls evaluation.

摘要

跌倒是長者常見的問題，與發病率、死亡率和護老院的比例有顯著的關係。綜合性多因素的跌倒評估， 應配合治療從而改善可改變的危險因素，並降低再次跌倒的機會。至少每年一次詢問長者有否跌倒的病史， 將曾跌倒、或反復跌倒，或是行動不穩的病人，轉介給熟悉跌倒綜合評估的醫生或專業人仕跟進。

Introduction

Fall is an important subject in geriatrics. It is because falls are prevalent among elderly people and they are closely linked to other major areas in geriatric medicine including incontinence, immobility, intellectual impairment and iatrogenesis. The aim of this article is to review common causes and risk assessment of falls in elderly population in community.

Definition of fall

Fall is often defined as an event which results in a person coming to rest inadvertently on the ground or other lower level and other than a consequence of the following: sustaining a violent blow; loss of consciousness (LOC); sudden onset of paralysis, as in a stoke; or epileptic seizure.¹ It is also defined simpler as a sudden and unintentional coming to rest at a lower level or on the floor.²

Epidemiology

Falls are the most common and serious problems in elderly population. Falls are associated with significant mortality, morbidity and reduced functioning. Community-based surveys indicated that approximately 30% of persons older than age 65 fell each year.³ About half of these fallers had multiple fall episodes, and the likelihood of fall increased with age.

In a 12 months cohort study which investigated the occurrence and the correlates of falls of 1947 local community dwelling elderly aged 70 years and above,⁴ 18% of the subjects sustained at least one fall. Most falls resulted in an injury of some types, usually minor soft tissue injuries such as bruises and abrasions. However, 10 % of falls resulted in fracture, with approximately 1% of these falls resulted in hip fracture.⁵ Those elderly persons who survived after hip fractures often suffered from permanent disability and dependency. More than 75% of all patients who suffered from a hip fracture were discharged to a nursing home. Fewer than 50% of patients were able to walk independently 1 year after hip fracture and fewer than 30% regained their pre-fracture level of physical functioning.⁶

Falls accounted for 75% of home accidents among patients aged 65 or above who presented to an emergency department of a regional hospital in Hong Kong.⁷ Falls cause not only injuries to elderly, but also mortality occasionally. Death can be a direct result of the injury sustained after fall; death can also be a subsequent complication after injury (e.g., hypostatic pneumonia, pulmonary embolism or stress ulcer with gastro-intestinal bleeding). In the United States of America, accident is the fifth leading cause of death in older people: two third of which were due to fall. As shown in a large epidemiological study of elderly persons seeking emergency care after a fall, 2.2% of injurious falls resulted in death.⁸

Fallers are more likely to develop the fear of falling than those without falls; 24% of fallers in a cohort study acknowledged the fear but denied the effect on activities; 19% acknowledged the avoidance activities because of the fear of falling.⁹ Among community dwelling elderly fall is a strong predictor of placement in a skilled-nursing facility; the risk of nursing home admission is 10 folds higher in elderly with injurious falls than those without falls.¹⁰

Risk factors

The risk factors responsible for a fall can be intrinsic (i.e., age-related physiological changes, diseases and medications) or extrinsic (i.e., environmental hazards). Fall in older adults is rarely the result of a single factor only. It is important to remember that a single fall may be the result of interactions of multiple risk factors. Studies revealed the additive effect of multiple independent risk factors; Tinetti showed that the fall rate rose from 27% (no or one risk factor) to 78% (4 or more risk factors).¹¹ The most common risk factors for falls identified in 16 studies are muscle weakness, history of falls, gait deficit, balance deficit, use of assistive device, visual deficit, arthritis, impaired activities of daily living, depression, cognitive impairment and age older than 80.

Demographic data

Older persons with acute or chronic illnesses, female gender, advanced age, impairment in activities of daily living (ADL) and use of assistive device are risk factors for falls. These factors also reflect the state of frailty as well.¹²

History of falls

Previous history of falls is repeatedly found to be a significant risk factor for future falls. In a twelve-month prospective study of community dwelling elderly, the group with one or more falls at baseline was 5.9 times more susceptible to falls than the group without a fall even after adjustment of other confounders.¹³

Vision

Visual impairment is strongly associated with two or more falls in older adults. In addition to poor visual acuity, other visual problems such as reduced visual field, impaired contrast sensitivity and cataract may account for this association. In one case-control study (911 cases and 910 controls aged 60 years or older), which demonstrated the associations between impaired vision and risk of hip fracture, the risk of hip fractures was increased in those having poor vision (less than 20/100) in both eyes (OR = 2.4; 95% CI: 1.0, 6.1). Having no depth perception was associated with increased risk of hip fracture as well (OR = 6.0; 95% CI: 3.2, 11.1). The population attributable risk of hip fracture owing to poor visual acuity or depth perception was 40%.¹⁴

Peripheral neuropathy

A recent case-control study demonstrated that peripheral neuropathy (PN) was found to be significantly associated with the self-report of falls and postural instability. The PN subjects who fell demonstrated not only significantly worse vibration sense at the ankle and finger, but also significantly decreased uni-pedal stance time than other PN subjects who did not fall.¹⁵

Medications

Patients taking psychotropic medications appear to have about a 2-fold increased risk of falls and fractures comparing those not taking these drugs. The strongest evidence is the antidepressants.¹⁶ Recent studies suggest that the newer selective serotonin reuptake inhibitor (SSRI) antidepressants do not offer advantage over TCA.¹⁷ There is no difference in the effect on fall between those taking short-acting benzodiazepines and long-acting benzodiazepines. It may be the benzodiazepine dosage that matters, rather than the drug half-life.

In a meta-analysis of 29 studies by Leipzig RM et al,¹⁸ subjects reporting the use of more than three or four medications of any type were at increased risk of recurrent falls. Digoxin, type IA antiarrhythmic, and diuretic use are associated weakly with falls in older adults. In addition to these specific drug classes mentioned above, recent changes in the dosage of medication and the total number of at least four prescribed items also increase the risk of falls.

Chronic diseases

Parkinson's disease

Falls are common problems in Parkinson's disease and occurred in 68.3% of the subjects. Previous falls, disease duration, dementia, and loss of arm swing are independent predictors of falling in patients with Parkinson's disease. There are also significant associations between disease severity, balance impairment, depression and falling.¹⁹

Arthritis of lower extremities

Arthritis of hip or knee results in stiffness and pain on movement. Knee pain was found to be one of the major causes of falls in elderly Chinese.

Stroke

Stroke is another major disease that is associated with falls.²⁰ Weakness of the affected limbs, sensory loss, hemianopia and attention deficits are found to be the risk factors for falls in stroke victims.

Cognitive Impairment

Mild to moderate cognitive impairment is associated with a higher risk of falls and hip fractures. The risk of falls is five-fold higher for those with cognitive impairment than normal cognition individuals.¹¹ It is thought that demented persons often engage in high-risk activities and they are often unaware of the potential hazards of falls.

Evironmental factors

Older adults cite tripping and slipping as two of the most common reasons for a fall.²¹ An environmental assessment often identify the modifiable risk factors: such as inadequate or excessive lighting, rugs, floor mats, lack of handrails in toilets, furniture with inappropriate height for transfers or clutter at home.

Basic risk assessment

According to the guideline for the prevention of falls in older persons (developed and written by the American Geriatrics Society, British Geriatrics Society and American Academy of Orthopaedic Surgeons Panel on Falls Prevention), all older persons should be asked at least annually about falls.¹²

The guideline recommends that all older persons who report a single fall should have the "Get up & Go Test".²² This is done by observing the person's ability to stand up from a chair without using arms, walk for 3 metres and return (using a walking aid if and aid is typically employed). Those demonstrating no difficulty or unsteadiness need no further assessment. Those who have difficulty or demonstrate unsteadiness in performing the "Get up & Go Test" test require further assessment. Moreover, older persons with history of recurrent falls, those who are prone to injurious falls or presenting after a fall would require a more comprehensive and detailed assessment by a clinician with appropriate skills and experience or referral to a specialist (e.g., geriatrician).

Timed "Up & Go" Test is another simple but powerful and commonly used screening tool for gait and balance problems.²³ The subject is asked to get up out of a standard armchair, walk a distance of 3 metres, turn, walk back to the chair and sit down again. He/She should wear regular footwear and use any customary walking aid if applicable. No physical assistance should be given. The examiner should use a stopwatch to time this activity. Usually the test can be completed in less than 1 minute. The test has acceptable sensitivity and specificity; the inter-rater reliability of this test is very high (98-99%) and it correlates well with conventional balance scale and Barthel ADL index. It is a useful screening tool in a busy clinic. The test is interpreted as below²⁴ (Table 1).

Comprehensive multi-factorial fall risk assessment

Various controlled trials have proven that multi-factorial fall assessment coupled with intervention can reduce the likelihood of future falls. The purposes of a multi-factorial fall assessment are to assess how high the fall risk is and to identify specific risk factors for falls. It is important to look for all risk factors in an individual and extra effort should be made to identify those modifiable risk factors for possible intervention.

This evaluation and assessment should be performed by a healthcare professional or professionals with appropriate skills and experience, normally in the setting of a specialized falls service. A comprehensive fall evaluation and assessment should include components as shown in Table 2.

Conclusion

Falls are prevalent in the elderly population; it is often associated with significant morbidity, mortality and admissions to institutions. However, falls are preventable if risk factors associated can be corrected. Therefore, an elderly person who has risks of falls or history of falls should be referred for comprehensive fall evaluation.

Key messages

1. Falls are prevalent in the elderly population; this subject is closely related to and is associated with significant morbidity and mortality.
2. All elderly should be asked for the history of falls at least once a year.
3. Timed "Up & Go" Test is a simple but powerful screening tool for screening of gait and balance problems. A score of 20 seconds or above is suggestive of increased fall risk.
4. For those patients with fall history, history of recurrent falls or problems of mobility/instability, they should be referred to a clinician or specialist familiar with comprehensive falls evaluation.
5. Multi-factorial fall assessment coupled with intervention can reduce the likelihood of future falls.