Perspective. Making Geriatric Assessment Work: Selecting Useful Measures. Key Words: Geriatric assessment, Physical functioning.

Transcription

1 Perspective Making Geriatric Assessment Work: Selecting Useful Measures Often the goal of physical therapy is to reduce morbidity and prevent or delay loss of independence. The purpose of this article is to describe issues to consider when selecting measures of physical function for use with community-dwelling adults over the age of 65 years. We chose 16 measures of physical function for review because they have been used in studies of community-dwelling older adults and some psychometric properties of reliability and validity have been described in the literature. Three major issues are discussed: (1) appropriateness of the measure for community-dwelling older adults, (2) practical aspects of test administration, and (3) psychometric properties. These issues are illustrated using examples from the 16 measures. Two scenarios, applying the measures to the assessment of physical performance of community-dwelling well older people and to the assessment of physical performance of community-dwelling frail older people, are used to illustrate how this information can be used. [VanSwearingen JM, Brach JS. Making geriatric assessment work: selecting useful measures. Phys Ther. 2001;81: ] Key Words: Geriatric assessment, Physical functioning. Jessie M VanSwearingen Jennifer S Brach Physical Therapy. Volume 81. Number 6. June

2 The objective of this Assessment of a person s physical performance is part of the health care management of older people, 1,2 particularly for physical therapists for whom the goal of intervention is often to improve function or reduce morbidity. 3 Health care professionals need to recognize who has a problem, 4 to determine when interventions are necessary and often what those interventions should be, to select outcome measures, to predict physical function, and to plan for the public health needs of older adults. 4 7 The impact of geriatric assessment and interventions on morbidity, 1,2,8 10 such as improved performance of basic and instrumental activities of daily living (BADL and IADL) and optimal independence, remains to be demonstrated. We contend that the selection of appropriate measures is important for determining the effectiveness of geriatric assessment and interventions in reducing morbidity. Despite the number of older people living in the community rather than in institutions, 11 the literature has little information about the physical performance of community-dwelling older adults. The focus of this article is to provide our views on the appropriateness of measures for use, the practicality of administration, and some of the psychometric properties of some measures of physical function in community-dwelling older adults over the age of 65 years. Our objective is to provide clinicians working with community-dwelling older people with a guide to be used in selecting measures of physical function. Our intent was to review only measures of physical function at the disability level (ie, as defined by the World Health Organization s International Classification of Impairments, Disabilities, and Handicaps disablement scheme 12 ) and not to examine measures of individual body systems (ie, impairment level). Measures of balance or fitness, although sometimes considered as impairment-level measures, typically, in our opinion, represent assessment of the interaction of multiple body systems (much like gait) in the performance of the tests. Thus, we have included balance and fitness in our review. article is to provide clinicians working with communitydwelling older people with a guide to be used in selecting measures of physical function. Selecting Measures for Review Measures selected for review had to meet certain basic criteria. They must have been: (1) developed for and tested among communitydwelling older people, (2) shown to be measures that could be applied in almost any clinical setting with minimal equipment, cost, or special requirements, (3) described in peerreviewed studies of community-dwelling older people, and (4) reported to have some form of reliability and validity. The measures reviewed are listed in Table 1. We organized the description of the measures into 3 categories: (1) comprehensive physical performance of activities of daily living (ADL), (2) mobility and balance, and (3) fitness for activity. Within each category, performance-based measures are discussed first, followed by a discussion of self-report measures. Selecting a Measure for Clinical Use Previous investigators studying outcomes of interventions in older adults defined 3 major considerations: (1) appropriateness to the target population, (2) practical aspects of test administration, and (3) psychometric properties. 13,14 In this article, we discuss the selection of physical function measures relative to these 3 broad concerns. We recommend that readers should consult a more detailed guide of things to consider in selecting measures, the Standards for Tests and Measurements in JM VanSwearingen, PT, PhD, is Associate Professor of Physical Therapy, Department of Physical Therapy, School of Health and Rehabilitation Sciences, University of Pittsburgh, 6035 Forbes Tower, Pittsburgh, PA (USA) Address all correspondence to Dr VanSwearingen. JS Brach, PT, PhD, GCS, is Clinical Assistant Professor of Physical Therapy, Department of Physical Therapy, School of Health and Rehabilitation Sciences, University of Pittsburgh, and a postdoctoral fellow, Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh. Both authors provided concept/project design and writing VanSwearingen and Brach Physical Therapy. Volume 81. Number 6. June 2001

3 Table 1. Measures Reviewed Based on Results of MEDLINE Search a Scale 1966 February 2000 Berg Balance Scale Timed chair rise Functional Reach Test Functional Status Questionnaire Gait speed Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) Modified Gait Abnormality Rating Scale Modified seated step test Performance-Oriented Mobility Assessment Physical Activity Scale for the Elderly Physical Performance Test Rosow-Breslau Scale Sickness Impact Profile 27, Six-Minute Walk Test Balance Timed Up & Go Test February 2000 a Search of the National Library of Medicine MEDLINE database for the following key words: geriatric assessment, aged, physical function, mobility, gait, and balance. Measures listed were most commonly cited in the search results and met the criteria cited in the text. The number of citations of each measure is reported for the entire database (1966 to February 2000) and for the past decade only (1990 to February 2000). Physical Therapy Practice,* for additional direction in choosing assessment instruments. Selecting a Measure: Appropriateness to the Target Population We believe that measures should be chosen based on whether they were designed and have been used with people similar to the people to be measured. 16,17 For example, if a measure could be used to determine whether an older patient in the hospital recovering from pneumonia and nearing discharge has recovered physical function adequate to return home. We believe that a measure of physical function in ADL designed and examined for use with community-dwelling older people should be chosen. We do not believe that the Barthel Index of ADL, 18 designed for use with institutionalized older adults, would be appropriate. In our view, the Physical Performance Test (PPT), which was designed and tested on a sample of community-dwelling older * The Standards for Tests and Measurements in Physical Therapy Practice 15 were developed by the American Physical Therapy Association s Task Force on Standards for Measurement in Physical Therapy in 1991 and referred to in the Guide to Physical Therapist Practice (rev ed, 1999) for clinical issues of measurement by physical therapists. The specific standards highlighted in the Standards of Tests and Measurements in Physical Therapy Practice, particularly those recommended for the tertiary purveyor (ie, teacher) and user of measures, further define issues within the major areas of concern. people, could enable the user to describe the physical function of the older person. 19 Limitations in measurements, such as ceiling or floor effects, can usually be avoided by selecting measures that have been demonstrated to provide meaningful information about people who are similar to those being measured. Ceiling or floor effects, meaning a large number of individuals receive the maximum or minimum score, limit the ability of a test user to show change. 16 Measures for which a sizable proportion of those measured perform at the ceiling or floor level typically fail to provide meaningful information. 20 For example, in one study of self-reported physical performance of community-dwelling older people using the Functional Status Questionnaire (FSQ), 64% of the people obtained the highest or ceiling level score for the BADL subscale and 23% scored the highest for the IADL subscale. 20 The FSQ would then have limited ability to provide much information about improvements in physical function because many older people scored the maximum prior to the intervention. In contrast, for the same group of community-dwelling older people, only 4% of the people scored at that level for the PPT, and 8% performed at that level for the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) physical function subscale. For all of the scales (ie, FSQ- BADL, FSQ-IADL, 7-item PPT, and SF-36 physical function subscale), 0% of the people scored at the lowest or floor level. 20 If the purpose of the measure is to describe performance and to be able to monitor change (eg, response to treatment or decline in physical function), the wide range of scores represented in the sample using the PPT and the SF-36 physical function subscale indicate that these 2 measures may be more useful than the FSQ. Face validity indicates whether a measure appears to have been designed to measure what it is supposed to measure, and, for our purposes, that is physical function of older people. Face validity, while contributing to validity of the data obtained with a measure, is not represented by the outcome of a statistical test but by the judgment of the tester that the measure has been used under similar conditions of measurement. 21 In our view, appropriateness for those being measured and face validity appear to be the first considerations for selecting a measure. This, in our view, quickly narrows the possible choices. For example, the Timed Up & Go Test (TUG) was designed and tested as a measure of mobility. 22 The recommended interpretation of TUG scores is based on distinguishing older people who are mostly independent in mobility and chair-to-stand transfers (TUG score of 20 seconds) from those who need assistance in most mobility and chair-to-stand transfers (TUG score of 30 Physical Therapy. Volume 81. Number 6. June 2001 VanSwearingen and Brach. 1235

4 seconds). 22 The relationship between timed scores for the TUG and risk of falling for older people has not been determined. Thus, we believe that the TUG could not be expected to provide useful information about the risk of an older person falling (but see VanSwearingen 23 ). Selecting a Measure: Practicality Practicality should be considered when choosing a test. Factors to consider are: (1) the time needed to administer the test, (2) the experience needed by the person administering the test (eg, professional or technical), (3) whether administering the test requires prior experience or formal training, (4) the equipment needed, (5) the format of the test (self-report or performancebased), (6) the method of scoring (eg, manually or computer-assisted), and (7) the format of the resulting measurements. 16,24,25 Practicality: Time Needed to Administer the Test In choosing a test, the time to complete the test and the patient s ability to tolerate testing without fatigue should be considered. For example, although patients may appear to have the time to complete self-report measures in the waiting room before being seen for therapy, we believe that lengthy or numerous self-report forms could interfere with patient care. Some older people (as well as some younger people), in our opinion, may fatigue while completing self-report forms, and this fatigue could influence their responses. We contend, therefore, that the SF may be preferred for use instead of the Sickness Impact Profile (SIP) 27 for self-report of physical function in ADL because the SF-36 is brief compared with the SIP, which contains 136 questions in 12 categories. Practicality: Experience of the Person Administering the Test The issue of skill may influence the choice of a test. In our view, nonprofessional support personnel, with even minimal training, may obtain measurements using the Functional Reach Test, 28 the TUG, gait speed, 29,30 chair rise time, 31 and balance measures. 32 In contrast, some measures of mobility and balance such as the Berg Balance Scale 33 and the Modified Gait Abnormality Rating Scale (GARS-M), 34 in our opinion, appear to require and have been tested using only the expertise of a professional to make judgments about performance relative to standards for the items of the test. To a lesser degree, we assume that the Performance-Oriented Mobility Assessment (POMA) 35 requires professional expertise, although much of the reported use of the POMA does not appear to have involved a physical therapist in the application of the test Timed tests of physical function often results in scores based on the time needed to complete a task. For example, on the PPT, item scores range from 0 to 4, based on the time for completion of the task, with the exception of one item that involves a criterion-based judgment (ie, turning 360 ). We believe that the PPT can be administered by support personnel or by a physical therapist with similar results. Practicality: Administering the Test Requires Prior Experience or Formal Training Instructions for administration of a test sometimes are not sufficient, and special training and experience are needed to achieve an acceptable level of accuracy in measurement. 21,39 The Berg Balance Scale 33 and the GARS-M 34 have been described in reports of studies in which the raters were trained. Both tests have instructions for testing individual items; however, initial reliability and validity testing of the measures was based on raters who compared item scoring on trial testing of sample patients, discussing discrepancies in scoring until agreement was reached prior to the actual use of the measure. 33,34 Other users could not expect similar accuracy of measurement without similar experience and training and would need to determine the reliability for specific conditions of measurement that differ from those previously described. The seated step test 40 does not involve what we would consider a novel measurement scale or calibration of raters, as we believe the GARS-M and the Berg Balance Scale do, and can be administered, in our opinion, by any personnel trained in recording vital signs. In practice, however, seated step tests 40 require the tester to be experienced in manually recording an exercising heart rate and blood pressure. The Six-Minute Walk Test, 41 based on distance walked and not a recording of exercising vital signs, might serve, in our opinion, as a more reasonable measure of endurance than the seated step tests, if testing personnel have limited experience with the measurement of vital signs. Practicality: Equipment Needed The equipment needed to obtain some measurements of physical function can be costly, as can time for setup and operation, in addition to the space required for equipment. If the equipment is not portable, transport or operation of the equipment in settings where community-dwelling older people are measured (eg, free-standing outpatient clinics, home care) may be difficult or even impossible. We selected the measures discussed in this review because we believe that they can be used to obtain measurements in a variety of settings, with minimal equipment costs and without special setups to obtain the measurements (eg, obstacle course) VanSwearingen and Brach Physical Therapy. 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5 Practicality: Format of the Measure (Performance-based or Self-Report) Guralnik et al 21 described the advantages and disadvantages of performance-based and self-reported measures for older people. Performance-based measures typically are used to determine what older people can do in the setting in which the measurements are obtained (often a clinic, which is much different from the home or usual living environment). 21 Proponents of self-reported measures have argued that these measures reflect what a person does in a more usual or familiar setting. 39 Some self-reported measures have been demonstrated to yield reliable measurements 42,43 and are correlated with performance-based measures of physical function. 20,44 In 1995, Reuben et al 20 reported that the information obtained with performance-based and self-report measures of physical function is complementary. Thus, selecting a performance-based measure of physical function (eg, the PPT) and a self-report measure of physical function (eg, the SF-36 physical function and physical role function subscales) may maximize the description of physical function of the older patient. 44,45 For example, the performance-based measure indicates an older person s ability to perform functional tasks, whereas the self-report measure indicates a person s usual performance or perception (opinion) of his or her ability to perform functional tasks. 39 Self-report measures may be desirable when there are no professional or support staff to obtain performance-based measurements. Practicality: Method of Scoring Scores may be obtained while subjects are tested (eg, Functional Reach Test, distance reached in inches), derived from scores assigned to ratings of individual items (eg, PPT, FSQ, GARS-M), or scored through a coding system based on rules for combining various item scores for different subscale measures (eg, SF-36). The SF-36 and the SIP have complex processes (eg, differential weighting of items scores, combining items from multiple sections of the instruments) for calculating scores for each subscale of the instruments. Computer programs can be used for scoring the SF-36 and SIP, reducing the burden on the test administrator, but this delays scoring and interpretation of findings. We believe there is an argument for a clinician interested in immediate feedback and interpretation using the FSQ, a self-report of physical function during ADL. Items have individual point values assigned relative to the items, and subscale scores are transformed from the total for the questions answered to a 100-point basis with basic mathematical processes of addition, subtraction, division, and multiplication. 46 Although composite scores transformed to a 100-point basis result in a score for which the relative value is easily recognized (eg, 50/100 suggests that performance is 50% of maximum or of some criterion of performance), it is also true that transformed scores obscure clinical meaning and magnify change in the measurement, which is potentially a problem in statistical analyses. 24 Practicality: Format of Results or Reported Scores All of the instruments reviewed in this article result in a single composite score or in a composite score and subscale scores for components of the item being measured. A single composite score can be desirable for communicating findings to others 24 and for identifying older people who are at risk for difficulty in physical function. However, a single composite score may not represent an older person s physical function for a specific task or for all categories of performance. 24 Subscale scores for components of physical function, in our opinion, may be more useful for planning intervention and monitoring outcomes. Gait speed may be a sensitive measure of mobility and fall risk 3 and responsive to intervention, 47 but this measure may not provide the clinician with insight into problems in gait. Selecting a Measure: Psychometric Properties According to Kirshner and Guyatt, 48 clinical tests and measures have 3 uses: (1) to discriminate between individuals, (2) to predict a result or expected outcome, or (3) to evaluate change with time. The patient management model used in the Guide to Physical Therapist Practice 49 describes the following uses of clinical measures: (1) examination, evaluation, and diagnosis (discrimination), (2) prognosis (predict a result), or (3) intervention (evaluate change). Reliability Reliability indicates the degree to which 2 measures are alike. 15,50 Intraclass correlation coefficients (ICCs) for quantitative, continuous data and the Kappa statistic for determining agreement of categorical data are often used to represent reliability for measures used in examination, but other statistical tests also are used. Unlike the Kappa statistic, the percentage of agreement, when used to reflect reliability, can be used to estimate closeness of sets of measures, but it does not correct for chance agreement and may not represent reliability relative to any clinical group of patients. Statistical indexes of association (eg, Pearson product moment correlation coefficient [Pearson r], Spearman rho) indicate how 2 measures vary together, but they do not indicate the agreement between the measures. Thus, the Pearson correlation coefficient is rarely appropriate for representing reliability, whereas the ICC, indicating the degree of common variance between measures for continuous data, is a better representative of agreement. 50 The standard error of the measurement (SEM) is the most desirable statistic for estimating reliability of measurements obtained with an instrument. 50 However, the Physical Therapy. Volume 81. Number 6. June 2001 VanSwearingen and Brach. 1237

6 SEM requires a large sample size (eg, measurements) to be accurate. 51 For the purposes of prognosis or prediction, reliability estimates determined using measures of agreement 48 seem to us appropriate. For example, values of the time to rise from and return to sit in a chair (ie, chair rise time) have been determined for quartiles, 34 with the expectation that the quartiles indicate a ranking of risk for disability (eg, older people in the second quartile at greater risk for disability than those in the third quartile). Using the chair rise time to classify older people and to make prognoses of the risk for functional decline necessitates, in our view, a reliability calculation using an ICC or Kappa statistic of agreement. Validity Measures used for evaluation and for determining the outcome of intervention, in our opinion, should relate to other measures (ie, have criterion-based validity) based on whether the other measures relate to the theoretical constructs underlying the measure (eg, content and construct validity). 52,53 The PPT measure of physical function during ADL has been demonstrated to have some validity for some inferences for some subjects by comparison with previous performance-based measures of function (eg, walking speed, POMA) and selfreport (eg, Rosow-Breslau Scale, SF-36, FSQ) at one point in time. 19 Chair rise time also has been associated with physical function and thus we contend would be valid for evaluating an outcome of physical function, 31,54 but not for predicting risk of falling. When used to make a prognosis (eg, to predict a future event), the purpose of balance measures is often to recognize older people who are likely to fall. 55 The criterion for these balance measures then should be the ability of the measure to predict falls, not the ability to detect or predict an intermediate outcome such as improved balance or reduced postural sway. This logic was used by reviewers who identified studies included in a systematic analysis of best evidence for interventions for reducing falls among older people. 55 Of the measures of community-dwelling older people reviewed, the Berg Balance Scale, PPT, GARS-M, gait speed, and Functional Reach Test meet, to some extent, tests for criterion validity for balance measures (eg, all have been studied for the association with an outcome of falls for older people). 3,56 58 The TUG and POMA, although associated with other measures of fall risk, have not been independently demonstrated to be related to the outcome of falls for older people. Sensitivity and specificity are important characteristics of measures used for screening because, when these indexes are used in this context, the intent is to identify Figure. Receiver operating characteristic (ROC) curve for use of walking speed for recognizing risk of recurrent falls among community-dwelling older people with frailty. individuals whose performance places them at risk for a designated problem. 4,59 Effective practice often depends on correctly identifying the person who will develop problems and tailoring interventions to prevent the occurrence of the problems. 6 A cutoff score for any measure is the value at which the optimal combination of sensitivity and specificity can be obtained. Cutoff scores can be determined from the receiver operating characteristic (ROC) curve, a plot of the sensitivity versus 1 specificity. 60 Optimal cutoff values for a specific purpose (eg, predicting fall risk, future disability) are determined from observing the ROC curve for the point that provides the best combination of sensitivity and specificity, the point closest to the upper left-hand corner of the curve. 60 For example, on the ROC curve for identifying the risk of recurrent falls from the gait speed of an older person, the optimal cutoff value for identifying fall risk is 0.56 m/s (Figure). Subsequently, likelihood ratios (sensitivity/1 specificity or true positive/false positive) for the measures are determined to indicate the odds of correctly identifying the older person with or without an increased risk for a specific physical function deficit (eg, falling), given a certain value of the measure. 4 The meaning of a cutoff score, particularly changing a cutoff score, becomes apparent from the ROC curve, illustrating the trade-off between sensitivity and specificity. 17 For example a cutoff score of 0.50 m/s for walking speed would be associated with a 4 to 1 likelihood of identifying a person who is at risk for falling from a person who is not at risk for falling. Selecting a walking speed of 0.62 m/s as the cutoff score for fall risk reduces the likelihood to 2 to 1 of identifying a person who is at risk for falling from a person who is not at risk for falling (Figure). Cutoff scores determined in a manner other than from the ROC curve do not provide the clinician with the same confidence in the prognosis or prediction VanSwearingen and Brach Physical Therapy. Volume 81. Number 6. June 2001

7 Measures with known predictive validity allow clinicians to make statements about expected outcomes or performance (prognosis), and this can be helpful in treatment and discharge planning. The physical therapist knowing the predictive validity of measures of physical function for independence in ADL 61 will be able to plan for appropriate community services and living arrangements. The performance-based PPT has some predictive validity for identifying who will be residing in a nursing home or dead 18 months later, 61 the self-report FSQ has predictive validity for death 51 months later, 62 and the short performance battery of lower-extremity function has predictive validity for mobility and ADL disability 4 years later among community-dwelling older people. 63 Predictive validity of a measure can also provide a meaningful standard of expected performance, which can be used to determine whether interventions change the expected outcome. 64 The responsiveness of a measure is its ability to detect clinically meaningful change over time. 65 Responsiveness of a measure is a critical issue for determining the results of interventions. 52,53 Effect size (ES) (standard deviation of baseline values/mean of the baseline values) and standard response mean (SRM) (standard deviation of the change pre-intervention to postintervention/mean of the change pre-intervention to post-intervention) represent the responsiveness of a measure and can be used to compare responsiveness with other outcome measures. 65 For example, in a study of the responsiveness of the SF-36, the ES and SRM of the SF-36 subscales were small, suggesting that the scale scores did not change dramatically with the intervention for the older people. 66 Performance-based measures have been shown to be more responsive to change, detecting a change (eg, preclinical) in physical function before the change becomes measurable by self-reported BADL and IADL scales. 45 Changes in self-reported measures may parallel but not match the magnitude of changes in performance-based measures of impairment and disability. 21 The smaller the change detected by a measure (better responsiveness), the greater confidence the clinician has that modest changes in the measurements represent real change. Responsiveness determined by comparing data obtained with a measure that is known to be responsive or by detecting changes after an intervention that is known to be efficacious assures clinicians that the measure is detecting meaningful change. 65 Review of Selected Measures Comprehensive Physical Performance Performance-based Measures Physical Performance Test. 19 The PPT, a measure of usual daily activities, including both BADL and IADL, is a performance-based global measure of physical performance. Developed and tested in frail and well community-dwelling and institutionalized older adults, the PPT has been used to describe and monitor physical performance, 19 to screen for falls, 3 and to predict the need for institutionalization and the likelihood of death. 61 There are 2 versions of the PPT: a 7-item version and a 9-item version. The 7-item PPT consists of the following items: writing a sentence, simulated eating, donning and doffing a jacket, turning 360 degrees while standing, lifting a book, picking up a penny from the floor, and walking 15.2 m (50 ft). For the 9-item PPT, 2 stair-climbing tasks time to climb a flight of stairs and number of flights climbed (maximum 4) are added to the items of the 7-item test. 19 The PPT takes about 10 minutes to administer and requires only a few simple props, making the measure practical in most clinical settings. Scoring for the majority of the items of the PPT is based on the time it takes to complete the item, reducing the potential for rater bias. Scores on the 7-item and 9-item PPTs range from 0 to 28 and 0 to 36, respectively, with higher scores representing better performance. The PPT involves performance of usual daily tasks; thus, instructions are minimal. In our experience, some older people who do not respond to the verbal request to perform a task when being tested recognize the task when it is demonstrated or presented with the prop (eg, a bowl and spoon) and perform the task appropriately. The PPT was designed for and tested on community-dwelling older adults, and the total score can be compared with percentile rankings for community-dwelling older adults. This should allow clinicians to place an individual s performance in the context of the performance of a population of people over 65 years of age and living in the community. Interrater reliability for both the 7-item PPT and the 9-item PPT has been determined in a sample of 6 individuals from a geriatric medicine group practice. 19 Given the small sample size and the use of the Pearson correlation coefficient, however, we believe that we really cannot state what the reliability is for the measure. Concurrent validity (Pearson r.50.80) was established by comparing the PPT with accepted functional status assessments (ie, Rosow-Breslau Scale, IADL, ADL, POMA) in a sample of 183 patients from geriatric outpatient clinics, senior housing units, board-and-care Physical Therapy. Volume 81. Number 6. June 2001 VanSwearingen and Brach. 1239

8 facilities, and a clinic specializing in the treatment of people with Parkinson disease. 19 The predictive validity for institutionalization and mortality has also been demonstrated in a study of 149 individuals from 3 different settings (a senior citizen housing unit, an ambulatorybased geriatrics practice, and a board-and-care facility). 61 The PPT has also been used to identify individuals who are at risk for recurrent falls (n 84) (sensitivity 78%, specificity 71%, cutoff score 15). 3 Comprehensive Physical Performance Self-Report Measures Functional Status Questionnaire. 46 The FSQ is a selfreport measure of physical, psychological, and social role functions in patients who are ambulatory. 46 The FSQ has been widely used to screen and monitor functional status (Tab. 1). 46,62 The FSQ can be quickly administered, taking approximately 15 minutes to complete. The 6 subscales can be used individually or as a composite. 46 An important aspect of the FSQ is the ease of scoring and what we believe are readily understood subscales and summary scores, which are transformed to a 100-point scale (lower scores represent greater limitations). In addition, if a question is left unanswered, the instrument can still be scored. Warning zones (ie, score ranges indicating functional disabilities) 46 have been developed for each of the 6 subscales to identify individuals with potential problems. 46,62 The FSQ has been shown to yield internally consistent measurements for the various subscales (.64.82). 46 The ADL and IADL subscales have demonstrated high internal consistency (.79 and.82, respectively). 46 The social activity subscale also has internal consistency (.65). 46 High internal consistency indicates that the items of the subscale reflect a single concept or phenomenon. 50 The FSQ has been shown to exhibit construct and convergent validity based on correlations with 7 health measures such as reported bed disability days and restricted activity days for older people (mean age 76 years, age range years; N 83). 20 Scores in the warning zone for the social activities and IADL subscales were independently predictive of mortality. 62 Medical Outcomes Study 36-Item Short-Form Health Survey. 26 The SF-36 is a general measure of health status that was designed for use in clinical practice and research, for health policy evaluations, and for general population surveys. The SF-36 is a self-report measure, with 8 subscales of health: limitations in physical function, physical role, social function, emotional role, bodily pain, mental health, vitality, and general health perceptions. The SF-36, a relatively short questionnaire (10 minutes to complete), can be self-administered or administered by a trained interviewer in person or over the phone. In older adults (aged 75 years and older) with poor physical or mental health, some assistance may be needed to complete the questionnaire. 67 Scoring can be complex and may require a computer to aid in the process. Scores on each of the subscales range from 0 to 100, with a score of 0 representing worst health and a score of 100 representing best health. Psychometric properties have been established in both a general medical outpatient population and a frail older adult population. Internal consistency was established with Cronbach alpha coefficients of.85 and reliability coefficients of Test-retest reliability (ICC.65.87) was determined by administering the SF-36 twice, 1 month apart, in a sample of 186 older adults (65 years of age and older). 69 In a sample of frail older people (over the age of 65 years of age) with one or more limitations of ADL admitted to a restorative care or day-hospital care facility for older adults, Cronbach alpha coefficients for internal consistency (a measure of the reliability of tests items for representing a single construct) were within the range of.72 to.91 for the 8 subscales (N 131), and ICCs for test-retest reliability ranged from.24 to.80, with the ICCs between.61 and.80 (n 41) for all except one of the test subscales. 66 Because groups with expected health differences could be differentiated, measurements obtained with the SF-36 have some validity. 68 In people who are considered to be at risk for acute deterioration of their health because of age (over 75 years of age) or because of debilitating medical diagnoses (in people 50 to 74 years of age), the bodily pain, social function, physical role, and emotional role subscales may demonstrate a problematic ceiling or floor effect. 70 The ability of the SF-36 to detect changes over a 12-month period (responsiveness) was examined in a sample of 131 frail older adults (65 years of age and older). Changes in mean scores over time were found for all scales of the SF-36 except the general health and emotional role subscales. Compared with other measures (eg, Barthel Index, Older Americans Research and Service Center Instrument [OARS]-IADL scale, Spitzer Quality of Life Index), all 8 subscales of the SF-36 were less responsive. 66 The SF-36 was originally developed to assess health-related quality of life in a more general population (mean age 54 years, 71% less than 65 years of age; uncomplicated medical diagnoses; N 2,293), so the lack of responsiveness in a frail older population is not surprising VanSwearingen and Brach Physical Therapy. Volume 81. Number 6. June 2001

9 Rosow-Breslau Scale. 71 The Rosow-Breslau Scale is a questionnaire developed in the 1960s to evaluate the relative difficulty of performing tasks of daily living for people with a high-level of physical function. 19,71 Although the items of the Rosow-Breslau Scale are physically challenging, they are typical of tasks faced by community-dwelling older adults (eg, walk a half mile, walk up to the second floor and down, perform heavy housework). The instrument, in our view, may not be good for measuring the range of performance exhibited by many community-dwelling older adults who are ambulatory and who demonstrate greater disability. Test-retest reliability for the Rosow-Breslau Scale was examined in a sample of 177 older adults with a mean age of 76.9 years. The Rosow-Breslau Scale was administered twice, on average, 21 days apart. The test-retest reliability was assessed using the Pearson correlation coefficient (Pearson r.81). Because the Pearson correlation coefficient is a measure of association and rarely appropriate for representing reliability, we cannot be sure of how much error (lack of reliability) is associated with this measure. This correlation also may have been inflated because many of the individuals did not report any functional limitations (n 69). After excluding the individuals with no functional limitations, the Pearson correlation coefficient decreased slightly to Concurrent validity of measurements obtained with the Rosow-Breslau Scale was established by comparison with other measures of physical performance. 19 Sickness Impact Profile. 73 The SIP is a multidimensional measure of health status and the impact of sickness. The SIP has been used extensively in both younger and older individuals to describe and monitor health status The scale consists of 136 items in 12 different categories: sleep and rest, emotional behavior, mobility, body care and movement, eating, ambulation, recreation and pastimes, social behavior, communication, alertness behavior, home management, and work. The SIP, a relatively lengthy questionnaire, can be either self-administered or interviewer administered. However, Bergner et al 79 found that, when the SIP was administered through the mail, slightly different information was obtained than when the questionnaire was administered in person. The SIP has been used for both younger people (ages 3 14 years, years, 75 and years 76 ) and older people (ages years, years, 77 and 65 years 78 ), and respondent age does not appear to be a factor in the use of the scale. 80 Scores on the SIP are expressed as a percentage from 0% to 100%, with higher scores representing greater dysfunction. Overall, category, and dimension scores can be calculated. 79 Some psychometric properties have been established for the SIP. Initially, reliability was determined using different interviewers, different forms, different administration procedures, and subjects with varying levels of dysfunction. In this study, 73 internal consistency (.94) was also determined. Test-retest reliability was determined by administering the SIP twice, 24 hours apart, in a sample of 119 subjects (age range years). 73 The Pearson product moment correlation was used to examine test-retest reliability for the overall SIP score. 73 As stated previously, however, the Pearson correlation coefficient is a measure of association and is rarely appropriate for representing reliability; an ICC to determine the common variance between measures is a better statistical choice. The validity of measurements obtained with the SIP was established by comparison with self-assessment of dysfunction (Pearson r.69) and self-assessment of sickness (Pearson r.63) and with clinician assessment of dysfunction (Pearson r.50). The SIP was also correlated to the National Health Interview Survey (Pearson r.55), and the instrument could discriminate among subsamples of patients. 27 In a sample of older adults without impairments (mean age 72.5 years), scores on the SIP were strongly skewed toward low (good health) scores, with 27% of the subjects having a score of 0%. 81 Responsiveness of the SIP was determined in 7 longitudinal projects that differed by the diagnoses of the patients studied in each project. Changes in health indicated by clinical judgment and other health status indexes were associated with changes in SIP scores. Thus, the changes in functional status were identified using the SIP, and the changes appeared to be valid representations of changes in health-related functional status. 82 Mobility and Balance Performance-based Measures Berg Balance Scale. 33 The Berg Balance Scale is a performance-based measure designed to monitor performance during balance activities, 33 to screen for individuals who therapists perceive would benefit from a physical therapy referral, 5 and to predict multiple falls in community-dwelling and institutionalized older adults. 83 The Berg Balance Scale consists of 14 common tasks, requires only a few props, and takes approximately 15 to 20 minutes to administer. The 14 items are scored on a 5-point ordinal scale (0 unable to perform, 4 independent) based on ability to complete the task and time for completion. The scores on the 14 items are combined for a total score, which can range from 0 to 56, with a higher score relating to better performance. Physical Therapy. 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10 The Berg Balance Scale has some established psychometric properties. The Cronbach alpha value for internal consistency for the entire scale for a sample of older adults (N 38) was Interrater reliability was determined by having one physical therapist administer the test and rate 14 older people and then having 5 physical therapists rate the same 14 patients from videotaped recordings of the evaluation (ICC.98) 33 ; for individual items, reliability ranged from.71 to.99. Four of the physical therapists rated the same videotapes of the balance testing 1 week later and determined intrarater reliability for the total score to be ICC.99; for individual items, the ICCs ranged from.71 to Interrater reliability determined with multiple raters using videotapes of the administration of the test indicates the reliability of scoring the test and not the reliability of test administration by multiple raters. Concurrent validity for the Berg Balance Scale as a measure of balance and mobility was determined by comparison with tests of postural sway (Pearson r.55), the POMA balance subscale (Pearson r.91), and the TUG (Pearson r.76). 83 The Berg Balance Scale has been used to identify individuals who would benefit from a referral for physical therapy as determined by the recommendation of physical therapists based on a screening physical examination (sensitivity 84% and specificity 78% using a cutoff score for referral of 48). 5 In addition, a score of less than 45 was shown to be predictive of risk for recurrent falls by a meta-analysis (N 110 older people) 55 and predictive of a future fall in 113 older people. 57 Functional Reach Test. 28 The Functional Reach Test was developed as a measure of the margin of stability. The Functional Reach Test has been used to describe and monitor an individual s balance 28 and to screen for or predict an individual who is at risk for falling. 58 The Functional Reach Test is an easily administered performance-based measure. The test consists of measuring the distance that an individual can reach forward without moving his or her feet. The score is the distance (in inches) that the person can reach. Variations of the test, having individuals reach in different directions, have been suggested. Shumway-Cook and Woollacott 84 referred to age-related normative values for functional reach for men and women in 2 age groups: people aged 41 to 69 years and people aged 70 to 87 years. However, we argue that the values should not be considered age-related norms, given the design of the original research from which the values were taken. The values of functional reach by age groups in the original study 28 were based on small numbers (age years: 22 men, 28 women; age years: 20 men, 14 women). We believe the sample was not representative of the general older adult community-dwelling population (eg, volunteers, excluded left-hand dominant people, smaller number of female subjects although the number of women substantially exceeds the number of men among the oldest old), and there was no indication of the range of ages within the groups. 28 Test-retest reliability (ICC.81) and interrater reliability were demonstrated in a sample of 128 volunteers whose ages ranged from 21 to 87 years. 28 Concurrent validity for balance and physical function was established by comparison with center-of-pressure excursion (Pearson r.71) and various measures of physical performance (Spearman rho, r.64.71) in a sample of 45 community-dwelling older adults aged 66 to 104 years. 85 Predictive validity for falls has also been determined in a prospective study of a sample of 217 male veterans. 58 Compared with people who reached 25.4 cm or more, people with a reach of greater than 15.2 cm but less than 25.4 cm were twice as likely to fall, people with a reach of 15.2 cm or less were 4 times more likely to fall, and people who could not reach were 8 times more likely to fall (fall likelihood referring to people who fell 2 or more times in 6 months). The odds ratios for the category of reach give the strength of association between a category and recurrent falls, but they indicate little about the meaning of a specific value relative to the risk for recurrent falls, as all categories are relative to the group who could reach 25.4 cm or more. In addition, of the individuals who were unable to perform the reaching task (score 0, n 24), only 8 (33.3%) reported 2 or more falls. Therefore, although individuals who were unable to reach were 8 times more likely than the people who could reach 25.4 cm or more, only 33% of the people who were unable to reach fell 2 or more times in 6 months. A cutoff score for risk of recurrent falls determined from a ROC curve plotted from the sensitivity and specificity of reach values for recognizing people with a history of recurrent falls should indicate the predictive ability of the measure, but this has not been reported. We question whether the Functional Reach Test is a measure of balance, because a recent study measuring reach in elderly people without impairments and individuals with vestibular hypofunction, who were expected to have poor balance, showed no difference in functional reach distance between the 2 groups. 86 Gait speed. 29 Gait speed is an extremely common measure used to describe and monitor mobility 29,87 and to screen for falls 3 in older adults. Gait speed is easy to measure by timing an individual while he or she walks at a habitual pace over a known distance. The distances used to calculate gait speed have ranged from 6 m 88,89 to 20 m. 87,90, VanSwearingen and Brach Physical Therapy. Volume 81. Number 6. June 2001

11 Test-retest reliability (Pearson r.93, ICC.78), with 48 hours between measurements, was established in a sample of 199 adults who were over 55 years of age (60% of the sample was over 70 years of age). 42 The sample represents a spectrum of ages of older adults living in the community, not a subgroup of only young old adults. In people who were more frail (N 105), test-retest reliability for measurements obtained approximately 2 weeks apart was ICC Gait speed has been shown to be a valid measure of the ability to walk in older adults (over 60 years of age) by comparison with stride length (Pearson r.93, n ; r.84, n 27 and r.88, n 22 for those with and without a history of falls, respectively 90 ), cadence (Pearson r.74, n ), and double support time (Pearson r.86, n ) and by comparison with a measure of gait abnormalities associated with falling (Spearman rho, r.68, n ; r.82, n 27 and r.79, n 22 for those at risk and not at risk for recurrent falls, respectively 90 ). Sensitivity (72%) and specificity (74%) of gait speed for recognizing the risk of recurrent falls have been determined by physical therapists recording gait speed in frail older adults, including a cutoff score of 0.56 m/s for risk of recurrent falls. 3 Sensitivity (80%) and specificity (89%) using a cutoff score of 0.57 m/s for identifying individuals who would benefit from physical therapy evaluation and possible treatment (as determined by comparison with recommendations of physical therapists conducting screening physical examinations) have also been established. 5 Modified Gait Abnormality Rating Scale. 34 The original Gait Abnormality Rating Scale (GARS) 90 from which the GARS-M was derived was designed to measure abnormalities of gait for older adults who are at risk for falling. The GARS has been used to describe gait and to distinguish people who are likely to fall from other nursing home residents, 90 whereas the GARS-M has been tested most extensively on community-dwelling, frail older adults. 3,34 The GARS-M is a 7-item measure designed to identify abnormalities of gait for older adults who are at risk for falling. The GARS-M is administered by videotaping the individuals as they walk on level surfaces. The 7 items of the GARS-M gait variability, guardedness, staggering, foot contact, hip range of motion, shoulder extension, and arm heel-strike synchrony are scored from the videotape of the individual walking. The 7 items of the GARS-M are scored on a 4 point criterion scale (0 3), with higher scores representing poorer performance. The total score of the GARS-M ranges from 0 to 21, with higher scores indicating greater abnormality and risk for falling. One advantage of the GARS-M is that anyone can videotape the subject walking and the professional can presumably score the GARS-M from the videotape at a more convenient time. A range of measurement characteristics has been established on the GARS-M. The GARS-M has demonstrated interrater reliability (Kappa coefficient [ ].97) and intrarater reliability (.97). 34 The Kappa coefficient statistic was used to indicate agreement of raters because the GARS-M is a categorical measure. Item scores represent a description of gait and are ranked by presumed difficulty (0 3), but the distance between scores is not equivalent. 93 Concurrent validity of data obtained with the GARS-M was determined by comparison with temporal and spatial gait characteristics. Construct validity of data obtained with the GARS-M was determined by the ability of the measure to distinguish older adults with a history of recurrent falls from older adults without a history of recurrent falls. 34 Sensitivity (62.3%) and specificity (87.1%) for risk of recurrent falls have been determined, with a cutoff score of 9 for identifying individuals who are at risk for recurrent falls. 3 Performance-Oriented Mobility Assessment. 35 The POMA is a widely used clinical measure of gait and balance in community-dwelling older adults. 5,35,38,94,95 The POMA has been used to describe and monitor balance and gait and to identify individuals who are at risk for falling. The original version of the POMA consisted of the direct observation of the performance of 13 balance skills (eg, sit-to-stand transfers, standing balance, turning 360 ) and 9 gait skills (eg, initiation of gait, step length and height, path deviation) and rating the skills as normal, adaptive, or abnormal. 35 In subsequent versions, the individual items have been scored using a criterionbased scale, with scores ranging from 0 to 1 or from 0 to 2. The item scores are combined for a balance scale score, a gait scale score, and a total score. Since the original version, 35 several different versions of the balance and gait scales have been described, with variability in the items included and scoring of the subscales. We have found 5 different versions of the POMA (Tab. 2). The items included in the gait and balance subscales and the scoring of the subscales differed. For example, balance subscale scores excluded some items, used a descriptive score (eg, normal, adaptive, abnormal ), or used a numerical score (eg, 0 1, 0 2), and total scores differed (11, 15, and 16) for the 5 versions. All of the investigators who wrote about these versions referred to the original version of the POMA 35 as the source for scoring and for psychometric properties. Only Robbins et al 94 reported using a modified version of the POMA, but these authors did not indicate how the scale was modified or what items were included in the modified version. Physical Therapy. Volume 81. Number 6. June 2001 VanSwearingen and Brach. 1243