Susan W. Muir

Use of the Berg Balance Scale for Predicting Multiple Falls in Community-Dwelling Elderly People: A Prospective Study

Background and Purpose: Falls are a significant public health concern for older adults; early identification of people at high risk for falling facilitates the provision of rehabilitation treatment to reduce future fall risk. The objective of this prospective cohort study was to examine the predictive validity of the Berg Balance Scale (BBS) for 3 types of outcomes—any fall (≥1 fall), multiple falls (≥2 falls), and injurious falls—by use of sensitivity, specificity, receiver operating characteristic (ROC) curves, area under the curve, and likelihood ratios. Subjects and Methods: A sample of 210 community-dwelling older adults received a comprehensive geriatric assessment at baseline, which included the BBS to measure balance. Data on prospective falls were collected monthly for a year. The predictive validity of the BBS for the identification of future fall risk was evaluated. Results: The BBS had good discriminative ability to predict multiple falls when ROC analysis was used. However, the use of the BBS as a dichotomous scale, with a threshold of ≤45, was inadequate for the identification of the majority of people at risk for falling in the future, with sensitivities of 25% and 45% for any fall and for multiple falls, respectively. The use of likelihood ratios, maintaining the BBS as a multilevel scale, demonstrated a gradient of risk across scores, with fall risk increasing as scores decreased. Discussion and Conclusion: The use of the BBS as a dichotomous scale to identify people at high risk for falling should be discouraged because it fails to identify the majority of such people. The predictive validity of this scale for multiple falls is superior to that for other types of falls, and the use of likelihood ratios preserves the gradient of risk across the whole range of scores.

Effect of vitamin D supplementation on muscle strength, gait and balance in older adults: a systematic review and meta-analysis.

To systematically review and quantitatively synthesize the effect of vitamin D supplementation on muscle strength, gait, and balance in older adults.

Dual-Task Complexity Affects Gait in People With Mild Cognitive Impairment: The Interplay Between Gait Variability, Dual Tasking, and Risk of Falls

OBJECTIVE To determine the effect of 2 different dual tasks on gait variability in people with mild cognitive impairment (MCI) compared with control subjects. DESIGN Cross-sectional study. SETTING Memory clinic at a university hospital. PARTICIPANTS Older adults with MCI (n=43) and cognitively normal control subjects (n=25) from the community. Gait was assessed under single (usual walking) and dual tasking (naming animals and subtracting serial 7s), using an electronic walkway. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES The dependent variable was the coefficient of variation of gait variability, a marker of gait stability and an established risk factor for falls. Two-way repeated-measures analysis of variance was used to examine main effects (group, task) and their interaction. RESULTS A significant difference was found within and between groups (P=.016) of increasing gait variability as dual-task complexity increased. Gait velocity decreased within groups as dual-task complexity increased. The magnitude of increased gait variability across tasks was greater for the MCI group (2.68%- 9.84%) than for the control group (1.86%-3.74%), showing a significant between-group difference (P=.041). CONCLUSIONS Dual-task load significantly increased gait variability in the MCI group compared with the control group, an effect that was larger than the changes in gait velocity. The magnitude of this impairment on gait stability was related to the complexity of the dual task applied. Our findings help to explain the high risk of falls recently described in older adults with MCI, and may help in the identification of fall risk in cognitively impaired persons.

Quantifying the magnitude of risk for balance impairment on falls in community-dwelling older adults: a systematic review and meta-analysis

OBJECTIVES To evaluate and summarize the evidence linking balance impairment as a risk factor for falls in community-dwelling older adults. STUDY DESIGN AND SETTING Systematic review and meta-analysis. English language articles in MEDLINE, EMBASE, CINAHL (1988-2009), under keywords of accidental falls, aged, risk factors, and hip, radius, ulna, and humerus fractures; and bibliographies of retrieved articles. Community-dwelling older adults in a prospective study, at least 1-year duration, age more than 60 years, and samples not specific to a single disease-defined population were included. Sample size, inclusion/exclusion criteria, demographics, clinical balance measurement scale, type of fall outcome, method of fall ascertainment, length of follow-up, and odds ratio (OR) or risk ratio (RR) were extracted. Studies must have reported adjustment for confounders. Random effects meta-analysis to generate summary risk estimate was used. A priori evaluation of sources of heterogeneity was performed. RESULTS Twenty-three studies met the selection criteria. A single summary measure could not be calculated because of the nonequivalence of the OR and RR, producing an overall fall risk of RR of 1.42 (1.08, 1.85) and OR of 1.98 (1.60, 2.46). CONCLUSIONS Balance impairment imparts a moderate increase on fall risk in community-dwelling older adults. The type of fall outcome, the length of follow-up, and the balance measurement tool impact the magnitude of the association. Specific balance measurement scales were identified with associations for an increased fall risk, but further research is required to refine recommendations for their use in clinical practice.

Gait assessment in mild cognitive impairment and Alzheimer's disease: The effect of dual-task challenges across the cognitive spectrum

Gait impairment is a prominent falls risk factor and a prevalent feature among older adults with cognitive impairment. However, there is a lack of comparative studies on gait performance and fall risk covering the continuum from normal cognition through mild cognitive impairment (MCI) to Alzheimers disease (AD). We evaluated gait performance and the response to dual-task challenges in older adults with AD, MCI and normal cognition without a history of falls. We hypothesized that, in older people without history of falls, gait performance will deteriorate across the cognitive spectrum with changes being more evident under dual-tasking. Gait was assessed using an electronic walkway under single and three dual-tasks conditions. Gait velocity and stride time variability were not significantly different between the three groups under the single-task condition. By contrast, significant differences of decreasing velocity (p<0.0001), increasing stride time (p=0.0057) and increasing stride time variability (p=0.0037) were found under dual-task testing for people with MCI and AD. Less automatic and more complex dual-task tests, such as naming animals and serial subtraction by sevens from 100, created the greatest deterioration of gait performance. Gait changes under dual-tasking for the MCI and AD groups were statistically different from the cognitively normal controls. Dual-task assessment exposed gait impairments not obvious under a single-task test condition and may facilitate falls risk identification in cognitively impaired persons without a history of falls.

Balance Impairment as a Risk Factor for Falls in Community-Dwelling Older Adults Who Are High Functioning: A Prospective Study

Background Screening should have simple and easy-to-administer methods that identify impairments associated with future fall risk, but there is a lack of literature supporting validation for their use. Objective The aim of this study was to evaluate the independent contribution of balance assessment on future fall risk, using 5 methods to quantify balance impairment, for the outcomes “any fall” and “any injurious fall” in community-dwelling older adults who are higher functioning. Design This was a prospective cohort study. Methods A sample of 210 community-dwelling older adults (70% male, 30% female; mean age=79.9 years, SD=4.7) received a comprehensive geriatric assessment at baseline, which included the Berg Balance Scale to measure balance. Information on daily falls was collected for 12 months by each participants monthly submission of a falls log calendar. Results Seventy-eight people (43%) fell, of whom 54 (30%) sustained an injurious fall and 32 (18%) had recurrent falls (≥2 falls). Different balance measurement methods identified different numbers of people as impaired. Adjusted relative risk (RR) estimates for an increased risk of any fall were 1.58 (95% confidence interval [CI]=1.06, 2.35) for self-report of balance problems, 1.58 (95% CI=1.03, 2.41) for one-leg stance, and 1.46 (95% CI=1.02, 2.09) for limits of stability. An adjusted RR estimate for an increased risk of an injurious fall of 1.95 (95% CI=1.15, 3.31) was found for self-report of balance problems. Limitations The study was a secondary analysis of data. Conclusions Not all methods of evaluating balance impairment are associated with falls. The number of people identified as having balance impairment varies with the measurement tool; therefore, the measurement tools are not interchangeable or equivalent in defining an at-risk population. The thresholds established in this study indicate individuals who should receive further comprehensive fall assessment and treatment to prevent falls.

Gait Variability Is Associated With Frailty in Community-dwelling Older Adults

BACKGROUND The relationship between frailty and gait characteristics other than velocity has received little attention. Gait variability quantifies the automaticity of gait with greater variability usually indicating an irregular and unstable gait. High gait variability reflects the loss of gait regulation and predicts mobility decline and falls, which may reveal systemic vulnerability. Thus, we hypothesize that high gait variability may be associated with frailty phenotype. METHODS Cross-sectional study including 100 community-dwelling women and men 75 years and older. Frailty was defined using validated phenotypic criteria and two additional frailty indexes that omit gait velocity criterion were used to verify associations between frailty and quantitative gait parameters. Gait was assessed under usual and fast pace using an electronic walkway. RESULTS Frailty phenotype was identified in 20% of the participants and at least one component of frailty was present in 75%. Linear regression models were generated to explore the associations between frailty and gait variability. In the univariate regression model, frailty was associated with higher variability for all the gait parameters of interest. After adjustments, stride time variability under fast gait condition was the most prominent parameter consistently associated with frailty. This association remained significant in two additional frailty indexes that omit gait velocity criterion. CONCLUSION Frailty is associated with low performance in several quantitative gait parameters beyond velocity of which the most prominent is high stride time variability. This finding may help to understand the high risk of falls and mobility decline in people with frailty.

Phenotype of Osteosarcopenia in Older Individuals With a History of Falling

OBJECTIVES In older persons, the combination of osteopenia/osteoporosis and sarcopenia has been proposed as a subset of frailer individuals at higher risk of institutionalization, falls, and fractures. However, the particular clinical, biochemical, and functional characteristics of the osteosarcopenic (OS) patients remain unknown. In this study, we used a clinical definition of osteosarcopenia aiming to determine the clinical, functional, and biochemical features that are unique to these patients within a population of older people who fall. DESIGN Cross-sectional study. SETTING Falls and Fractures Clinic, Nepean Hospital (Penrith, NSW, Australia). PARTICIPANTS A total of 680 people (mean age = 79, 65% women) assessed between 2009 and 2013. MEASUREMENTS Assessment included medical history, physical examination, bone densitometry and body composition by dual-energy X-ray absorptiometry, posturography, grip strength, gait parameters (GaitRITE), and blood tests for nutrition and secondary causes of sarcopenia and osteoporosis. Patients were divided into 4 groups: (1) osteopenic (BMD <-1.0 SD), (2) sarcopenic, (3) OS, and (4) nonsarcopenic/nonosteopenic. Difference between groups was assessed with 1-way ANOVA and χ(2) analysis. Multivariable linear regression evaluated the association between the groups and measures of physical function. Multivariable logistic regression evaluated risk factors for being in the OS group. RESULTS Mean age of the OS patients was 80.4 ± 7.0 years. Our analyses showed that OS patients are older, mostly women, are at high risk for depression and malnutrition, have body mass index lower than 25, and showed a higher prevalence of peptic disease, inflammatory arthritis, maternal hip fracture, history of atraumatic fracture, and impaired mobility. CONCLUSION We have reported a set of characteristics that are highly prevalent in OS patients. This study could be used to inform the design of future trials and to develop interventions to prevent institutionalization and poor outcomes in this particular set of high-risk patients.

Vitamin D and Brain Imaging in the Elderly: Should we Expect Some Lesions Specifically Related to Hypovitaminosis D?

Hypovitaminosis D is associated with cognitive decline in the elderly, but the issue of causality remains unresolved. Definitive evidence would include the visualization of brain lesions resulting from hypovitaminosis D. The aim of the present article is to determine, through a literature review, the location and nature of possible brain disorders in hypovitaminosis D. We found limited brain-imaging data, which reported ischemic infarcts and white matter hyperintensities in hypovitaminosis D, though did not provide their specific location or report any focal atrophy. Based on the finding of executive dysfunctions (i.e., mental shifting and information updating impairments) in the presence of hypovitaminosis D, we suggest that hypovitaminosis D is associated with a dysfunction of the frontal-subcortical neuronal circuits, particularly the dorsolateral circuit. Further imaging studies are required to corroborate this assumption and to determine whether hypovitaminosis D results in degenerative and / or vascular lesions.

Association of executive function impairment, history of falls and physical performance in older adults: A cross-sectional population-based study in Eastern France

ObjectiveTo estimate: 1) the association between executive function (EF) impairment and falls; and 2) the association of EF impairment on tests of physical function used in the evaluation of fall risk.DesignCross-sectional study.SettingThirteen health examination centres in Eastern France.ParticipantsFour thousand four hundred and eighty one community-dwelling older adults without dementia aged 65 to 97 years (mean age 71.8±5.4, women 47.6%).MeasurementsParticipants underwent a comprehensive medical assessment that included evaluations of EF using the Clock Drawing Test and of physical performance using the Timed Up & Go Test (TUG). Analysis used multivariable modified Poisson regression to evaluate the association between impaired EF and each of the fall outcomes (any fall, recurrent falls, fall-related injuries). Multivariable linear regression was used to evaluate the association between EF impairment and performance on the TUG and grip strength.ResultsEF impairment, assessed using the clock drawing test, was present in 24.9% of participants. EF impairment was independently associated with an increased risk of any fall (RR=1.13, 95% CI (1.03, 1.25)) and major soft tissue fall-related injury (RR= 2.42, 95% CI (1.47, 4.00)). Additionally, EF impairment was associated with worse performance on the TUG (p<0.0001).ConclusionsEF impairment among older adults without dementia was highly prevalent and was independently associated with an increased risk for falls, fall-related injuries and with decreased physical function. The use of the Clock Drawing Test is an easy to administer measure of EF that can be used routinely in comprehensive fall risk evaluations.