Predicting the Probability for Falls in Community-Dwelling Older Adults Using the Timed Up & Go Test.The Timed Up & Go Test (TUG) is a test of balance that is commonly used to examine functional mobility in community-dwelling, frail frail 1 adj. frail·er, frail·est 1. Physically weak; delicate: an invalid's frail body. 2. older adults (aged 70-84 years).[1] The test requires a subject to stand up, walk 3 m (10 ft), turn, walk back, and sit down. Time taken to complete the test is strongly correlated cor·re·late v. cor·re·lat·ed, cor·re·lat·ing, cor·re·lates v.tr. 1. To put or bring into causal, complementary, parallel, or reciprocal relation. 2. to level of functional mobility.[1] Older adults who are able to complete the task in less than 20 seconds have been shown to be independent in transfer tasks involved in activities of daily living, have high scores on the Berg Balance Scale, and walk at gait speeds that should be sufficient for community mobility (0.5 m/s).[1] In contrast, older adults requiring 30 seconds or longer to complete the task tend to be more dependent in activities of daily living, require assistive devices assistive device Public health Any device designed or adapted to help people with physical or emotional disorders to perform actions, tasks, and activities. See Americans with Disabilities Act, Architectural barriers, Assistive technology. for ambulation am·bu·late intr.v. am·bu·lat·ed, am·bu·lat·ing, am·bu·lates To walk from place to place; move about. [Latin ambul , and score lower on the Berg Balance Scale.[1] Although the TUG has been shown to be useful for predicting level of functional mobility, its validity for identifying community-dwelling older adults who are at risk for falls is unknown. Functional mobility is a term used to reflect the balance and gait maneuvers used in everyday life (eg, getting in and out of a chair, walking, turning).[1] Thus, one goal of our research was to determine the sensitivity and specificity of the TUG for predicting falls in community-dwelling older adults. Recent research has suggested that assessment of balance under multi-task conditions may be a more sensitive indicator of balance problems and falls than assessment of balance in a single-task context.[2-5] Researchers using laboratory tests of balance under dual-task conditions have found that the ability to maintain stability can be affected by performance of concurrent cognitive tasks,[2-4] and this effect is enhanced in older adults with balance impairments and a recent history of falls.[5] Lundin-Olsson and colleagues[6] investigated the effect of performing multiple tasks on balance, mobility, and falls in frail older adults who lived in an institutional setting. Physical frailty frailty Vox populi A state of delicacy or weakness which, which encompasses age-related fragility, in particular osteoporosis. See FICSIT, Osteoporosis. is defined by severely impaired strength, mobility, balance, and endurance. They modified the TUG to add a manual task ([TUG.sub.manual]) (ie, carrying a glass of water) and found that frail older adults who had a time difference of greater than 4.5 seconds between the [TUG.sub.manual] and the TUG were more prone to falls during the following 6 months. They concluded that the difference in time between the TUG and [TUG.sub.manual] is useful for identifying institutionalized in·sti·tu·tion·al·ize tr.v. in·sti·tu·tion·al·ized, in·sti·tu·tion·al·iz·ing, in·sti·tu·tion·al·iz·es 1. a. To make into, treat as, or give the character of an institution to. b. elderly people who are prone to falls.[6] Whether performance on the TUG in a dual-task condition is a useful measure for identifying community-dwelling older adults who are prone to falls is not known. Thus, another goal of our study was to determine whether, in community-dwelling older adults, the TUG performed under dual-task conditions was a more sensitive and specific predictor of falls than the TUG measure alone. In a previous study using a simultaneous task paradigm, we studied the effects of 2 types of secondary tasks (a spatial orientation task versus a language task) on postural control during stance under 2 surface conditions (firm versus compliant).[5] We compared the effects of these tasks on balance between a group of young adults (aged 24-44 years) and 2 groups of older adults (ie, those with a history of falls [aged 65-86 years] and those without a history of falls [aged 65-94 years]).[5] In young adults, neither secondary task affected stability in stance. In contrast, in the older nonfallers, the effect of a secondary task was dependent on the difficulty of the postural task. In the less challenging postural condition (standing on a firm surface), neither cognitive task affected balance; however, there was a significant increase in postural sway when cognitive tasks were performed in the more challenging postural condition (standing on a compliant foam surface). Finally, the older adults with balance problems and a history of recurrent falls swayed sway v. swayed, sway·ing, sways v.intr. 1. To swing back and forth or to and fro. See Synonyms at swing. 2. more when performing either secondary task even in the less challenging postural condition. Results from that study suggest that the effect of a secondary task on postural control was dependent on the balance abilities of the subject, the difficulty of the balance task, and the type of secondary task being performed.[5] The effects of different types of secondary tasks on functional mobility have not been determined. Certain types of secondary tasks performed in conjunction with the TUG may be more sensitive predictors of falls than others. Therefore, another goal of this study was to compare the sensitivity and specificity of 2 conditions of TUG performance (cognitive versus manual) in identifying community-dwelling older adults who are at risk for falls. Our hypotheses were (1) that, although the TUG itself would be a sensitive predictor of falls, the dual-task TUG would be a more sensitive predictor of falls than the TUG alone and (2) that the TUG with the addition of a cognitive task ([TUG.sub.cognitive]) would be a more specific and sensitive predictor of falls than the [TUG.sub.manual]. Method Subjects Thirty community-dwelling older adults living in the greater Seattle area were enrolled in the study after giving informed consent. The participants were volunteers recruited from subjects involved in previous aging studies that were carried out by the first author. The participants were 15 older adults with no history of falls (mean age = 78 years, SD = 6, range = 65-85) and 15 older adults with a history of 2 or more falls in the previous 6 months (mean age = 86.2 years, SD = 6, range = 76-95). The inclusion criteria
Inclusion criteria are a set of conditions that must be met in order to participate in a clinical trial. were that the subjects had to be aged 65 years or older, living independently in the community, able to walk 9.1 m (30 ft) with or without an assistive device but without the assistance of another person, able to follow simple instructions, and able to carry a cup by a handle. Criteria for inclusion in the group of older adults with a history of falls included a self-report of 2 or more falls within the past 6 months. A fall was defined as any event that led to an unplanned, unexpected contact with a supporting surface. We excluded falls resulting from unavoidable environmental hazards 'Environmental hazard' is a generic term for any situation or state of events which poses a threat to the surrounding environment. This term incorporates topics like pollution and Natural Hazards such as storms and earthquakes. such as a chair collapsing. In addition, we excluded people who had only 1 fall within 6 months in order to maximize the possibility of selecting a sample of older adults with recurrent fall problems. Further criteria for the older adults in the faller category included an absence of known neurological neurological, neurologic pertaining to or emanating from the nervous system or from neurology. neurological assessment evaluation of the health status of a patient with a nervous system disorder or dysfunction. or musculoskeletal musculoskeletal /mus·cu·lo·skel·e·tal/ (-skel´e-t'l) pertaining to or comprising the skeleton and muscles. mus·cu·lo·skel·e·tal adj. Relating to or involving the muscles and the skeleton. diagnosis that could account for possible imbalance and falls, such as cerebrovascular accident cerebrovascular accident n. Abbr. CVA See stroke. cerebrovascular accident Stroke, cerebral hemorrhage Neurology Sudden death of brain cells due to ↓ O2 , Parkinson disease Parkinson Disease Definition Parkinson disease (PD) is a progressive movement disorder marked by tremors, rigidity, slow movements (bradykinesia), and posture instability. , cardiac problems, transient ischemic attacks Transient Ischemic Attack Definition A transient ischemic attack, or TIA, is often described as a mini-stroke. Unlike a stroke, however, the symptoms can disappear within a few minutes. , or lower-extremity joint replacements. Procedure After informed consent was obtained, subjects completed a health status questionnaire providing information on age, residential status, marital status marital status, n the legal standing of a person in regard to his or her marriage state. , medical history, current coexisting co·ex·ist intr.v. co·ex·ist·ed, co·ex·ist·ing, co·ex·ists 1. To exist together, at the same time, or in the same place. 2. medical conditions See carpal tunnel syndrome, computer vision syndrome, dry eyes and deep vein thrombosis. , self-reported history of imbalance, type of assistive device used for ambulation, and use of prescription medications. This information was used to characterize the demographics The attributes of people in a particular geographic area. Used for marketing purposes, population, ethnic origins, religion, spoken language, income and age range are examples of demographic data. and health status of subjects participating in the study. In order to verify our classification of the 2 groups based on balance abilities, balance was measured using 1 self-report instrument and 2 performance-based measures. The Activities-specific Balance Confidence Scale (ABC ABC in full American Broadcasting Co. Major U.S. television network. It began when the expanding national radio network NBC split into the separate Red and Blue networks in 1928. ) is a self-report measure of balance that people can use to rate their perceived confidence related to balance when performing common activities of daily living.[7] We asked our subjects to use the ABC to rate their degree of confidence (1 = no confidence to 10 = full confidence) in performing 10 basic activities of daily living and instrumental activities of daily living instrumental activities of daily living A series of life functions necessary for maintaining a person's immediate environment–eg, obtaining food, cooking, laundering, housecleaning, managing one's medications, phone use; IADL measures a without fear of loss of balance. The result was a score ranging from 10 to 100. In a previous study examining the psychometric psy·cho·met·rics n. (used with a sing. verb) The branch of psychology that deals with the design, administration, and interpretation of quantitative tests for the measurement of psychological variables such as intelligence, aptitude, and properties of the ABC on 102 older adults living in the community, the ABC test-retest correlation (r) was .92 (P [is less than] .001), indicating good test-retest reliability test-retest reliability Psychology A measure of the ability of a psychologic testing instrument to yield the same result for a single Pt at 2 different test periods, which are closely spaced so that any variation detected reflects reliability of the instrument ; the Cronbach alpha was .96, indicating high internal consistency In statistics and research, internal consistency is a measure based on the correlations between different items on the same test (or the same subscale on a larger test). It measures whether several items that propose to measure the same general construct produce similar scores. .[7] The test did not discriminate dis·crim·i·nate v. dis·crim·i·nat·ed, dis·crim·i·nat·ing, dis·crim·i·nates v.intr. 1. a. fall status among community-dwelling older adults.[7] Subjects then underwent a 45-minute performance-based evaluation of balance and mobility function. Balance was evaluated using the Berg Balance Scale, which rates performance from 0 (cannot perform) to 4 (normal performance) on 14 different tasks, including ability to sit, stand, reach, lean over, turn and look over each shoulder, turn in a complete circle, and step.[8] The total possible score on the Berg Balance Scale is 56, which is supposed to indicate excellent balance. The Berg Balance Scale has been shown to yield measurements with excellent interrater and test-retest reliability (intraclass correlation In statistics, the intraclass correlation (or the intraclass correlation coefficient[1]) is a measure of correlation, consistency or conformity for a data set when it has multiple groups. coefficient [ICC ICC See: International Chamber of Commerce ] =.98 and .97, respectively) and good internal consistency (Cronbach alpha=.96).[8] Scores obtained from the Berg Balance Scale been shown to be correlated with scores obtained from other tests of balance and mobility, including the Tinetti Mobility Index (r=-.91) and the Get Up & Go Test (r=-.76).[9] Mobility was evaluated by asking subjects to walk for 3 minutes at their preferred speed. Distance walked was measured, and speed for self-paced gait was determined. Subject demographics and clinical test results are summarized in Table 1. Table 1. Demographics of Older Adults Without a History of Falls (n = 15) and Older Adults With a History of Falls (n = 15)
Nonfallers Fallers
Age(a) (y)
[bar]X 78.4 86.2
SD 5.8 6.4
Range 65-85 76-95
Sex
Female 10 (67%) 8 (53%)
Assistive device
None 15 (100%) 3 (20%)
Cane 7 (47%)
Walker 5 (33%)
No. of prescriptions
0-1 50% 42%
2-3 50% 42%
[is greater than or equal to] 4 16%
No. of comorbidities
0-1 82% 33%
2-3 18% 59%
[is greater than or equal to] 4 8%
Self-paced gait speed (m/s)(a) 1.2 (0.1) 0.47 (0.2)
Berg Balance Test(a)
(range 0-56) 55.5 (1) 32.7 (7.5)
Activities-specific Balance
Confidence Scale(a)
(range 0-100) 93.2 (7) 53.0 (17)
(a) Significant difference (P<.05) between groups. Experimental Protocol Subjects were asked to complete 3 trials of the TUG under 3 conditions: performance of the TUG alone, performance of the TUG with the addition of a cognitive task ([TUG.sub.cognitive]), and performance of the TUG with the addition of an upper-extremity motor task ([TUG.sub.manual]). The tasks were presented in random order. When performing the TUG, subjects were given verbal instructions to stand up from a chair, walk 3 m as quickly and as safely as possible, cross a line marked on the floor, turn around, walk back, and sit down. Those subjects who used an assistive device when walking in the community were requested to use that device. In the [TUG.sub.cognitive], subjects were asked to complete the test while counting backward by threes from a randomly selected number between 20 and 100. In the [TUG.sub.manual], subjects were asked to complete the test while carrying a full cup of water. Subjects who used a walker for ambulation (n=5) were excluded from this condition. Subjects were given one TUG practice trial to familiarize themselves with the task. Data Analysis Two raters measured performance by timing the TUG in all 3 conditions. Interrater reliability as measured with an ICC (3,3) was high, with [r.sub.i]=.98, .99, and .99 for the TUG, [TUG.sub.manual], and [TUG.sub.cognitive], respectively.[10] As a result, further analyses were performed on the data obtained from one rater rat·er n. 1. One that rates, especially one that establishes a rating. 2. One having an indicated rank or rating. Often used in combination: a third-rater; a first-rater. only. Histograms and descriptive statistics descriptive statistics see statistics. were calculated to determine distributions, detect outliers, and consider the need for transformations. A logarithmic logarithmic pertaining to logarithm. logarithmic relationship when the logs of two variables plotted against each other create a straight line. transformation was performed on time data due to nonnormality, the result of positively skewed skewed curve of a usually unimodal distribution with one tail drawn out more than the other and the median will lie above or below the mean. skewed Epidemiology adjective Referring to an asymmetrical distribution of a population or of data data. A multivariate analysis multivariate analysis, n a statistical approach used to evaluate multiple variables. multivariate analysis, n a set of techniques used when variation in several variables has to be studied simultaneously. of variance (MANOVA MANOVA Multivariate Analysis of the Variance ) was then performed to determine whether group differences existed on the transformed time measures. Scores were averaged over the 3 trials. In cases where the MANOVA demonstrated a difference (P [is less than] .05), a post hoc post hoc adv. & adj. In or of the form of an argument in which one event is asserted to be the cause of a later event simply by virtue of having happened earlier: within-subject analysis was performed. To determine the ability of the TUG performed under the 3 conditions to predict faller versus nonfaller group membership, cross-validated discriminant function discriminant function n. Statistics A function of a set of variables used to classify an object or event. analyses were performed on 5 variables: the 3 transformed timed measures and 2 difference measures ([TUG.sub.manual] - TUG and [TUG.sub.cognitive] - TUG). A prior probability prior probability, n the extent of belief held by a patient and practitioner in the ability of a specific therapeutic approach to produce a positive outcome before treatment begins. of classifying an older adult as a faller was set at 35%, based on falls rate literature.[11,12] A logistic regression In statistics, logistic regression is a regression model for binomially distributed response/dependent variables. It is useful for modeling the probability of an event occurring as a function of other factors. procedure was used to determine the cutoff value for each timed test that maximized sensitivity and specificity and predicted the probability of fallers at .5 or greater. All of these analyses were performed with SAS (1) (SAS Institute Inc., Cary, NC, www.sas.com) A software company that specializes in data warehousing and decision support software based on the SAS System. Founded in 1976, SAS is one of the world's largest privately held software companies. See SAS System. 6.12.[13],(*) The Pearson product moment correlation coefficient Correlation Coefficient A measure that determines the degree to which two variable's movements are associated. The correlation coefficient is calculated as: (r) was used in bivariate bi·var·i·ate adj. Mathematics Having two variables: bivariate binomial distribution. Adj. 1. correlations, and a 3-way analysis of variance was performed to compare demographics across the 2 groups. These analyses were performed using SPSS A statistical package from SPSS, Inc., Chicago (www.spss.com) that runs on PCs, most mainframes and minis and is used extensively in marketing research. It provides over 50 statistical processes, including regression analysis, correlation and analysis of variance. 8.0.[14],([dagger]) Results Results from the MANOVA showed that the older adults with a history of falls were slower (F=22.97, P [is less than] .001) than the older adults without a history of falls in all 3 conditions (TUG, [TUG.sub.cognitive], and [TUG.sub.manual]). Table 2 compares the time taken to complete the TUG in all 3 conditions for both groups of subjects. Table 2 Comparison of Time Taken (in Seconds) to Complete the TUG, [TUG.sub.manual], and [TUG.sub.cognitive] in Older Adults Without a History of Falls (n = 15) and Older Adults With a History of Falls (n = 15)(a)
TUG [TUG.sub.manual]
Nonfallers Fallers Nonfallers Fallers
[bar]X 8.4 22.2 9.7 27.2
SD 1.7 9.3 1.6 11
Range 6.4-12.6 10.3-39.2 6.9-12.6 14-48.7
[TUG.sub.cognitive]
Nonfallers Fallers
[bar]X 9.7 27.7
SD 2.3 11.6
Range 6.2-14.6 11-49.6
(a) TUG = Timed Up & Go Test, [TUG.sub.manual] = Timed Up & Go Test with addition of a manual task, [TUG.sub.cognitive] = Timed Up & Go Test with addition of a cognitive task Because there was a difference in age (t=-3.5, P=.002) between the older adults with a history of falls and the older adults without a history of falls, a MANCOVA MANCOVA Multivariate Analysis of Covariance was used to reanalyze the TUG data using age as a covariate. Using this analysis, there was still a difference in time taken to complete the TUG between the 2 groups, suggesting that the differences found in older subjects were not due to age alone, but rather due to balance status. In addition, the time taken to complete the TUG by the older adults with a history of falls was highly correlated (r=.95) with the type of assistive device used for ambulation. The time taken to complete the TUG with no device was 9.0 seconds (range=6.4-13.4), the time taken to complete the TUG with a cane cane, walking stick cane, walking stick. Probably used first as a weapon, it gradually took on the symbolism of strength and power and eventually authority and social prestige. was 18.1 seconds (range= 14.6-22.3), and the time taken to complete the TUG with a front-wheeled walker was 33.8 seconds (range=28.3-39.2). These results are illustrated in Figure 1. [Figure 1 ILLUSTRATION OMITTED] The addition of either a cognitive task or a manual task increased the time taken to complete the TUG in both groups of older adults (older adults with a history of falls: F=79.3, P [is less than] .001; older adults without a history of falls: F= 21.9, P [is less than] .001). Figure 2 compares the performance of individuals within each of the 2 groups on the 3 tasks. Table 3 displays the increase in time taken to complete the TUG in the 2 secondary task conditions for each of the 2 groups. In the older adults with a history of falls, the time taken to complete the [TUG.sub.cognitive] increased on average 25% compared with 16% in the older adults without a history of falls. The [TUG.sub.manual] increased 22% in the older adults with a history of falls compared with 15% in the older adus without a history of falls. [Figure 2 ILLUSTRATION OMITTED] Table 3. Difference in Time Taken to (in Seconds) Complete the [TUG.sub.manual] and [TUG.sub.cognitive] Compared With the TUG in Older Adults Without a History of Falls (n = 15) and Older Adults With a History of Falls (n = 15)(a)
[TUG.sub.cognitive] [TUG.sub.manual]
Nonfallers Fallers Nonfallers Fallers
[bar]X 1.28 5.56 1.32 4.98
SD 1.0 3.2 1.0 2.2
Range -0.3-3.0 0.7-11.7 0.01-3.9 2.2-10.9
(a) TUG = Timed Up & Go Test, [TUG.sub.manual] = Timed Up & Go Test with addition of a manual task, [TUG.sub.cognitive] = Timed Up & Go Test with addition of a cognitive task. Discriminate analysis Discriminate analysis A statistical process that links the probability of default to a specified set of financial ratios. indicated that the 3 measures (TUG, [TUG.sub.manual], and [TUG.sub.cognitive]) were equivalent with respect to classifying fallers and nonfallers, suggesting that all 3 tests were comparable for identifying community-dwelling older adults who are prone to falls. In Table 4, we compare the sensitivity and specificity for each of the 3 tests in predicting falls in community-dwelling older adults. The TUG alone correctly classified 13/15 fallers (87% sensitivity) and 13/15 nonfallers (87% specificity). Compared with the TUG under single-task conditions, use of the dual-task TUG (either cognitive or manual) to identify fall status decreased sensitivity to 80% while increasing specificity to 93%, thus maintaining a comparable overall prediction rate (87%). Using difference scores between the dual-task TUG and the single-task TUG to determine probability for falls resulted in lower prediction rates than when the actual test scores were used. Table 4. Comparison of the Sensitivity and Specificity for Identifying Older Adults With and Without a History of Falls(a)
Sensitivity Specificity
(% Fallers) (% Nonfallers)
TUG 13/15 (87%) 13/15 (87%)
[TUG.sub.manual] 12/15 (80%) 14/15 (93%)
[TUG.sub.cognitive] 12/15 (80%) 14/15 (93%)
[TUG.sub.manual] - TUG 10/15 (67%) 13/15 (87%)
[TUG.sub.cognitive] - TUG 7/15 (47%) 14/15 (93%)
Overall
Prediction
TUG 26/30 (87%)
[TUG.sub.manual] 26/30 (87%)
[TUG.sub.cognitive] 26/30 (87%)
[TUG.sub.manual] - TUG 23/30 (76%)
[TUG.sub.cognitive] - TUG 21/30 (70%)
(a) TUG = Timed Up & Go Test, [TUG.sub.manual] = Timed Up & Go Test with addition of a manual task, [TUG.sub.cognitive] = Timed Up & Go Test with addition of a cognitive task. Logistic regression analysis was used to determine cutoff levels for the TUG, the [TUG.sub.manual], and the [TUG.sub.cognitive]. Cutoff levels that maximized both sensitivity and specificity and had a predicted probability of .5 or larger were determined to identify the specific time score that best classified fallers and nonfallers. As shown in Table 5, older adults who took 13.5 seconds or longer to perform the TUG were classified as fallers with an overall correct prediction rate of 90%. On the [TUG.sub.manual], classification of older adults as fallers using the time score of 14.5 seconds or longer resulted in a 90% correct prediction rate. Finally, elderly subjects who completed the [TUG.sub.cognitive] in 15 seconds or longer were classified as fallers with an overall correct prediction rate of 87%. Table 5. Balance Test Cutoff Scores to Maximize Sensitivity, Specificity, and Predicted Probability(a)
Cutoff
Score (s)
TUG [is greater than or equal to] 13.5
[TUG.sub.manual] [is greater than or equal to] 14.5
[TUG.sub.cognitive] [is greater than or equal to] 15
Sensitivity Specificity
(% Fallers) (% Nonfallers)
TUG 80% 100%
[TUG.sub.manual] 86.7% 93.3%
[TUG.sub.cognitive] 80% 93.3%
Overall Predicted
Prediction Probability
TUG 90% .77
[TUG.sub.manual] 90% .5
[TUG.sub.cognitive] 86.7% .5
(a) TUG = Timed Up & Go Test, [TUG.sub.manual] = Timed Up & Go Test with addition of a manual task, [TUG.sub.cognitive] = Timed Up & Go Test with addition of a cognitive task. The relationship between fall status and time taken to perform the TUG in the 3 conditions is shown in Figure 3. In all 3 conditions, this relationship was nonlinear A system in which the output is not a uniform relationship to the input. nonlinear - (Scientific computation) A property of a system whose output is not proportional to its input. . For example, an individual who took 13 seconds to complete the TUG had a 69% probability of being a faller. An individual who took 14 seconds to complete the TUG had an 83% probability of being a faller. This nonlinearity could also be seen in the [TUG.sub.manual], where a 16-second score was associated with a 70% probability of being a faller, whereas the probability rose to 81% with a score of 17 seconds. [Figure 3 ILLUSTRATION OMITTED] Discussion and Conclusions We investigated the sensitivity and specificity of the TUG under both single and dual task conditions in identifying fall prone older adults living in the community. Our results indicate that the TUG itself is a sensitive and specific indicator of whether falls occur in community-dwelling older adults. Thus, we believe the TUG is a relatively simple screening test that takes only minutes to complete, and we contend that it appears to be a valid method for screening for both level of functional mobility and risk for falls in community-dwelling elderly people. Results from the discriminate analysis suggest that older adults who take longer than 14 seconds to complete the TUG have a high risk for falls. Our cutoff value of 14 seconds is different from that of Podsiadlo and Richardson,[1] who found that a cutoff value of greater than 30 seconds was best for predicting functional dependence among older adults. The differences in time values may reflect the differences in subjects used in the 2 studies. Podsiadlo and Richardson's study included older adults with a wide range of neurologic neurologic /neu·ro·log·ic/ (-loj´ik) pertaining to neurology or to the nervous system. Neurologic Having to do with the nervous system. pathologies. In contrast, we studied community-dwelling, frail older adults, but we excluded older adults with known neurologic diseases. Our finding that all 3 tests (TUG, [TUG.sub.manual], and [TUG.sub.cognitive]) were comparable in determining the likelihood of falling in community-dwelling older adults did not support our hypothesis that measurement of mobility under multi-task conditions would be a more sensitive indicator of likelihood for falls. In addition, difference scores (eg, [TUG.sub.manual]-TUG) did not increase the ability to identify community-dwelling older adults who are prone to falls. This finding is not consistent with Lundin-Olsson and colleagues'[6] finding that comparing mobility performance between single-task and dual-task conditions was a more useful way of predicting future falls in institutionalized elderly people. There are 2 dissimilarities between these studies that could explain these differences. First, Lundin-Olsson and colleagues studied a population of frail older adults living in an assisted-living environment. We examined older adults who, despite having balance impairments, were living independently within the community. Second, in Lundin-Olsson and colleagues' study, predictors of future falls were sought. In contrast, we were looking for Looking for In the context of general equities, this describing a buy interest in which a dealer is asked to offer stock, often involving a capital commitment. Antithesis of in touch with. measures that are useful for identifying individuals with a likelihood of falling. It may be that, although difference scores are not useful in a discriminate function, they may remain useful as predictors of future falls in some populations of elderly individuals. Effect of Multiple Tasks on Mobility in Elderly People Who Are Prone to Falls Results from this study confirm that simultaneous performance of a secondary task had a deleterious deleterious adj. harmful. effect on functional mobility. The addition of a secondary task increased the time taken to complete the TUG by 22% to 25%. This effect was independent of the type of secondary task performed (either manual or cognitive). These findings do not support our hypothesis that cognitive tasks would affect mobility more than manual tasks. Clinical Implications Given the incidence and consequences of falls among older adults, screening methods that identify elderly individuals who are prone to falls and who may benefit from interventions designed to improve balance and decrease falls and risk for falls are critical. Results from our study suggest that the TUG is a simple screening test that is a sensitive and specific measure of probability for falls among older adults. (*) SAS Institute SAS Institute Inc., headquartered in Cary, North Carolina, USA, has been a major producer of software since it was founded in 1976 by Anthony Barr, James Goodnight, John Sall and Jane Helwig. Inc, PO Box 8000, Cary, NC 27511. ([dagger]) SPSS Inc, 444 N Michigan Ave, Chicago, IL 60611. References [1] Podsiadlo D, Richardson S. The timed "Up & Go": a test of basic functional mobility for frail elderly frail elderly, n.pl older persons (usually over the age of 75 years) who are afflicted with physical or mental disabilities that may interfere with the ability to independently perform activities of daily living. persons. J Am Geriatr Soc. 1991;39: 142-148. [2] Guerts ACH (Automated Clearing House) A system of the U.S. Federal Reserve Bank that provides electronic funds transfer (EFT) between banks. It is used for all kinds of fund transfer transactions, including direct deposit of paychecks and monthly debits for routine payments to , Mulder TW, Nienhuis B, Rijken RAJ. Dual task assessment of reorganization in persons with lower limb amputation amputation (ăm'pyətā`shən), removal of all or part of a limb or other body part. Although amputation has been practiced for centuries, the development of sophisticated techniques for treatment and prevention of infection has greatly . Arch Phys Med Rehabil. 1991;72:1059-1064. [3] LaJoie Y, Teasdale N, Bard bard, in Wales, term originally used to refer to the order of minstrel-poets who composed and recited the poems that celebrated the feats of Celtic chieftains and warriors. C, Fleury M. Attentional demands for static and dynamic equilibrium dy·nam·ic equilibrium n. See equilibrium. . Exp Brain Res. 1993;97:139-144. [4] Lundin-Olsson L, Nyberg L, Gustafson Y. "Stops walking when talking" as a predictor of falls in elderly people. Lancet lancet /lan·cet/ (lan´set) a small, pointed, two-edged surgical knife. lan·cet n. . 1997;349(9052):617. [5] Shumway-Cook A, Woollacott M, Kerns Kerns is a municipality in the canton of Obwalden in Switzerland. It has a population of c. 5,200. KA, Baldwin M. The effects of two types of cognitive tasks on postural stability in older adults with and without a history of falls. J Gerontol A Biol Sci Med Sci. 1997;52:M232-M240. [6] Lundin-Olsson L, Nyberg L, Gustafson Y. Attention, frailty, and falls: the effect of a manual task on basic mobility. J Am Geriatr Soc. 1998;46:758-761. [7] Powell LE, Myers AM. The Activities-specific Balance Confidence (ABC) Scale. J Gerontol A Biol Sci Med Sci. 1995:50:M28-M34. [8] Berg KO, Wood-Dauphinee SL, Williams JI, Gayton D. Measuring balance in the elderly: preliminary development of an instrument. Physiotherapy physiotherapy: see physical therapy. Canada. 1989;41:304-311. [9] Berg KO, Wood-Dauphinee SL, Williams JT, et al. Measuring balance in the elderly: validation of an instrument. Can J Public Health. 1992;83(suppl 2):S7-S11. [10] Shrout PE, Fleiss JL. Intraclass correlations: uses in assessing rater reliability. Psychol Bull. 1979;86:420-428. [11] Lach HW, Reed AT, Arfken CL, et al. Falls in the elderly: reliability of a classification system. J Am Geriatr Soc. 1991;39:197-202. [12] Reinsch S, McRae P, Lachenbruch PA, Tobis JS. Attempts to prevent falls and injury: a prospective community study. The Gerontologist ger·on·tol·o·gy n. The scientific study of the biological, psychological, and sociological phenomena associated with old age and aging. ge·ron . 1992;32:450-456. [13] SAS/STAT Version 6.12. Cary, NC: SAS Institute Inc; 1996. [14] SPSS for Windows: Advanced Statistics, Release 8.0. Chicago, Ill: SPSS Inc; 1998. A Shumway-Cook, PT, PhD, is Associate Professor, Division of Physical Therapy, University of Washington, Box 356490, Seattle, WA 98195 (USA) (ashumway@u.washington.edu). Address all correspondence to Dr Shumway-Cook. S Brauer, PT, PhD, is Postdoctoral post·doc·tor·al also post·doc·tor·ate adj. Of, relating to, or engaged in academic study beyond the level of a doctoral degree. Noun 1. Fellow, Department of Exercise and Movement Science, University of Oregon The University of Oregon is a public university located in Eugene, Oregon. The university was founded in 1876, graduating its first class two years later. The University of Oregon is one of 60 members of the Association of American Universities. , Eugene, Ore. M Woollacott, PhD, is Professor and Chair, Department of Exercise and Movement Science, and Member, Institute of Neuroscience neu·ro·sci·ence n. Any of the sciences, such as neuroanatomy and neurobiology, that deal with the nervous system. neuroscience the embryology, anatomy, physiology, biochemistry and pharmacology of the nervous system. , University of Oregon. All authors provided concept/research design, writing, data collection and analysis, fund procurement The fancy word for "purchasing." The procurement department within an organization manages all the major purchases. , subjects, facilities and equipment, and institutional liaisons. The authors acknowledge Robin High, Statistical Consultant, for his statistical expertise. The study was approved by the Institutional Review Board of Northwest Hospital, Seattle, Wash. This investigation was supported by a grant from the Foundation for Physical Therapy to Dr Shumway-Cook and by National Institute on Aging The National Institute on Aging is a division of the U.S. National Institutes of Health, located in Bethesda, Maryland. Formed in 1974, NIA's mission is to improve the health and well-being of older Americans through research. It is the primary U.S. grant AG-05317 to Dr Woollacott. This article was submitted May 12, 1999, and was accepted May 30, 2000. |
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