Performance-based Measures Of Function Research Articles

Giving Meaning to Measure: Linking Self-Reported Fatigue and Function to Performance of Everyday Activities

Fatigue, a common symptom of cancer patients, particularly those on active treatment, is generally evaluated using self-report methods, yet it remains unclear how self-reported fatigue scores relate to performance of daily activities. This study examines the relationships among self-reported and performance-based measures of function in patients receiving chemotherapy (CT) to link self-reported fatigue measures to self-report and performance-based measures of function. Self-reported fatigue using the Functional Assessment of Chronic Illness Therapy–Fatigue (FACIT-F) and self-reported physical function using the physical function 10 subscale of the Short Form 36 (SF-36) (PF-10) were measured in 64 patients within 2 weeks of beginning CT (n=64) and after three cycles of CT (n=48). Motor and cognitive functions were captured using five self-reported and seven observed-performance measures at each time point. Significant correlations between self-reported and observed measures ranged from 0.30 to 0.71. Self-reported fatigue correlated (0.30–0.45) with performance-based function. FACIT-F scores in the range of 30 and below and PF-10 scores in the range of 50 and below were related to an increased difficulty performing everyday activities. Observed measures of physical performance correlate moderately with self-reported fatigue and self-reported physical function. These relationships enable one to begin linking fatigue scores directly to a person's ability to perform everyday activities.

Do actions speak louder than words? Self-assessed and performance-based measures of physical and visual function among old people

Self-assessments and performance-based tests are methods commonly used to assess physical function in health surveys of older people. It has been suggested that the choice of method could affect the results, particularly in certain groups. This study compares results attained using self-assessed and performance-based measures of upper and lower body function and vision. The influence of sex, age, education and cognitive status is explored. This is done by studying the prevalence rates of self-reported and observed limitations in function, the prevalence rates of discrepancies between measures and the prevalence rates as well as the odds ratios of discrepancies depending on sex, age, education and cognitive status. Data are from a nationally representative sample of the Swedish population aged 77 or above (n=492). The results show that discrepancies occur among a minority of the sample and with no distinctive bias toward either under- or overestimations of functional ability at the cross-sectional level. Cognitive impairment seemed to increase the risk of discrepancies. Women showed an increased tendency toward discrepancies between measures of upper body function. Age and education showed associations with some discrepancies but were not significant in the multiple regression models. In conclusion, there is a risk of systematic biases in the association between self-assessed and performance-based measures of function. At the cross-sectional level, however, these differences are small.

Executive Function Correlates with Walking Speed in Older Persons: The InCHIANTI Study

To study the association between performance on psychological tests of executive function and performance on lower extremity tasks with different attentional demands in a large sample of nondemented, older adults. Cross-sectional study. Community-based. Nine hundred twenty-six persons aged 65 and older, without dementia, stroke, parkinsonism, visual impairment, or current treatment with neuroleptics, enrolled in a large epidemiological study. Trail Making Test (TMT) parts A and B and two performance-based measures of lower extremity function that require different executive/attentional-demanding skills: walking speed on a 4-m course at usual pace and walking speed on a 7-m obstacle course at fast pace. A difference score (Delta TMT), obtained by subtracting time to perform part A from time to perform part B of the TMT, was used as an indicator of executive function. Based on Delta TMT, subjects were divided into poor performance, intermediate performance, and good performance. After adjustment, no association between Delta TMT and 4-m course usual-pace walking speed was found. Participants with poor Delta TMT and with intermediate Delta TMT performance were more likely to be in the lowest tertile for 7-m obstacle course walking speed. In nondemented older persons, executive function is independently associated with tasks of lower extremity function that require high attentional demand.

Functional Correlates and Prevalence of Mild Parkinsonian Signs in a Community Population of Older People

Mild parkinsonian signs (MPS) are associated with incident dementia and an increased risk of mortality. To our knowledge, the functional correlates of MPS have not been studied. To study the functional correlates of MPS, including self-reported and performance-based measures of function, and to determine the prevalence of MPS in a cohort of community-dwelling older people (aged >or=65 years). Participants (N = 1866) in the Washington Heights-Inwood Columbia Aging Project underwent a neurological assessment that included a modified motor portion of the Unified Parkinson's Disease Rating Scale, which yielded a parkinsonian sign score (range, 0-40) and parkinsonian sign subscores (axial function, rigidity, and tremor). A functional assessment included 3 self-reported measures of function and 2 performance-based tests. Participants with Parkinson disease were excluded. Mild parkinsonian signs were present in 469 (25.1%) of the 1866 participants. The parkinsonian sign score was correlated with functional and performance-based test scores (r = 0.24-0.32, P<.001). The axial function and rigidity subscores correlated to a greater extent with functional and performance-based test scores than did the tremor subscore. In analysis of covariance models, excluding participants with dementia and adjusting for age, sex, ethnicity, education, depressive symptoms, and medical illnesses (eg, arthritis), the parkinsonian sign score and age were strongly and independently associated with functional scores. Mild parkinsonian signs, and particularly axial dysfunction, were associated with functional disability, including self-reported and performance-based measures of functional difficulty. Given the high prevalence of these signs in elderly persons, MPS may be a significant indicator of disability in elderly persons.

Thrust during ambulation and the progression of knee osteoarthritis

To determine whether the presence of varus thrust at baseline increases the risk of progression of medial tibiofemoral osteoarthritis (OA), whether knees with thrust have a greater adduction moment, whether thrust has any additional impact on top of static varus, and whether thrust is associated with poor physical function outcome. Two hundred thirty-seven patients with knee OA (definite osteophytes and symptoms) underwent baseline gait observation to assess varus thrust and full-limb radiography to assess alignment. Sixty-four of these 237 patients also underwent quantitative gait analysis to determine the maximum knee adduction moment. Two hundred thirty patients (97%) returned for followup at 18 months. At baseline and 18 months, the 230 participants had semiflexed, fluoroscopically confirmed knee radiographs (with progression defined as worsening of medial joint space grade); self-reported and performance-based measures of function were also assessed. Logistic regression with generalized estimating equations was used to estimate odds ratios (ORs) for medial OA progression, after excluding knees that were not at risk for progression. Varus thrust was present in 67 of 401 knees. Thrust increased 4-fold (age-, sex-, body mass index-, and pain-adjusted OR 3.96, 95% confidence interval [95% CI] 2.11-7.43) the odds of medial progression, with some reduction after further adjustment for varus alignment severity. In varus-aligned knees, thrust increased the odds of OA progression 3-fold (adjusted OR 3.17, 95% CI 1.60-6.31). In the gait substudy, the adduction moment was greater in knees with a thrust compared with knees without a thrust. Having a thrust in both knees versus neither knee was associated with a 2-fold increase in the OR for poor physical function outcome (P not significant). Varus thrust is a potent risk factor, identifiable by simple gait observation, for disease progression in the medial compartment, the most common site of OA involvement at the knee. Varus thrust may also predict poor physical function outcome. Varus thrust increased the odds of progression among varus-aligned knees considered separately, suggesting that knees with a thrust are a subset of varus-aligned knees at particularly high risk for progression of OA.

Clinical Characteristics of Flexed Posture in Elderly Women

To investigate the relationships between the severity of flexed posture (FP), skeletal fragility, and functional status level in elderly women. Cross-sectional study. Geriatric rehabilitation research hospital. Sixty elderly women (aged 70-93) with FP referred to a geriatric rehabilitation department for chronic back pain without apparent comorbid conditions. Multidimensional clinical assessment included the severity of FP (standing occiput-to-wall distance) demographic (age) and anthropometric (height, weight) data, clinical profile (number of falls, pain assessment, Mini-Mental State Examination, Comorbidity Severity Index, Geriatric Depression Scale, Multidimensional Fatigue Inventory), measures of skeletal fragility (number of vertebral fractures by spine radiograph, bone mineral density (BMD), and T-score of lumbar spine and proximal femur), muscular impairment assessment (muscle strength and length), motor performance (Short Physical Performance Battery, Performance Oriented Mobility Assessment, instrumented gait analysis), and evaluation of disability (Barthel Index, Nottingham Extended Activities of Daily Living Index). The severity of FP was classified as mild in 11, moderate in 28, and severe in 21 patients. Although there were no differences between FP groups on the skeletal fragility measurements, the moderate and severe FP groups were significantly different from the mild FP group for greater pain at the level of the cervical and lumbar spine. The severe FP group was also significantly different from the mild but not the moderate FP group in the following categories: clinical profile (greater depression, reduced motivation), muscle impairment (weaker spine extensor, ankle plantarflexor, and dorsiflexor muscles; shorter pectoralis and hip flexor muscles), the motor function performance-based tests (lower scores in the balance and gait subsets of the Performance Oriented Mobility Assessment), the instrumented gait analysis (slower and wider base of support), and disability (lower score on the Nottingham Extended Activities of Daily Living Index). The total number of vertebral fractures was not associated with differences in severity of FP, demographic and anthropometric characteristics, clinical profile, muscular function, performance-based and instrumental measures of motor function, and disability, but it was associated with reduced proximal femur and lumbar spine BMD. The severity of FP in elderly female patients (without apparent comorbid conditions) is related to the severity of vertebral pain, emotional status, muscular impairments, and motor function but not to osteoporosis, and FP has a measurable effect on disability. In contrast, the presence of vertebral fractures in patients with FP is associated with lower BMD but not patients' clinical and functional status. Therefore, FP, back pain, and mobility problems can occur without osteoporosis. Older women with FP and vertebral pain may be candidates for rehabilitation interventions that address muscular impairments, posture, and behavior modification. Randomized controlled trials are needed to support these conclusions.

The 6-minute walk test in mobility-limited elders: what is being measured?

The 6-minute walk (6mw) is a well-established measure of aerobic capacity in elders with cardiorespiratory and peripheral vascular disease and may be an accurate measure of functional performance in healthy elders. In mobility-limited elders, a population at risk for disability, impairments in strength and power are predictive of performance-based measures of function. Though commonly utilized as an outcome measure among otherwise healthy mobility-limited elders, it is not clear whether the 6mw best represents a measure of functional limitation, aerobic capacity, or both. We hypothesized that the 6mw would be strongly representative of performance-based measures of function being determined by impairments in muscle strength and power. We performed a cross-sectional analysis of 45 community-dwelling elders with mild to moderate mobility limitations. The 6mw was strongly associated with established functional measures (r =.61-.83; p <.001), but was poorly associated with indirect measures of aerobic capacity (r <.25; p >.05). Multivariate linear regression models demonstrated that impairments in leg strength and power, especially those at the knee and ankle, were predictive of 6mw performance. These findings emphasize the 6mw as a measure of functional limitation among mobility-limited elders without cardiorespiratory or peripheral vascular disease.

A preliminary study on the reliability of physical performance measures in older day-care center clients with dementia.

Decline in physical functional ability is an intrinsic component of the dementia syndrome. Reductions in muscle mass and strength represent a major factor in the loss of functional ability Although resistance exercise has been studied as a method for maintaining/recovering function in populations of frail older adults, people with dementia have been systematically excluded because of uncertainty about the reliability of outcome measurements. The purpose of this study was to determine the test-retest reliability of a battery of established performance-based measures of strength and function among subjects with dementia. A hospital-affiliated adult day-care facility. Twelve of 28 older subjects with dementia of various etiologies were available for two assessments prior to implementation of a resistance-exercise intervention. Subjects underwent an assessment of lower extremity strength and physical function consisting of two recorded trials of bilateral isometric strength of the knee extensor, hip flexor, and dorsiflexor muscles, as well as hand grip strength; repeated chair stands, evaluation of usual- and maximal safe-gait speed over a 6-m course, and the Timed-Up-and-Go Test. The entire assessment was repeated approximately 1 week later. An average of the trials for each measurement was computed for each of the two assessment periods, and intraclass correlation coefficients (ICCs) for these paired measurements were estimated using STATA. ICCs ranged from .56 for left iliopsoas to .77 for left dorsiflexors among the strength measures whereas measures of function ranged from .80 for number of steps in usual gait to .95 for time of fast gait. Performance-based measures of strength and function can be reliably assessed in older people with dementia, although measures of function appear to be more reliable than measures of strength.

A short questionnaire on visual function of older adults to supplement ophthalmic examination

PURPOSE: To estimate frequency of self-reported visual dysfunction in specific life situations. METHODS: Performance-based measures of visual function were obtained during the 5-year follow-up examination of the Beaver Dam Eye Study cohort. During the subsequent yearly follow-up telephone call, four questions concerning visual abilities in specific situations were administered. RESULTS: Visual difficulties in everyday life situations were commonly reported by adults aged 48 to 91 years, with only 17% to 35% of persons reporting excellent or very good vision in the four specific situations related to visual function. Visual acuity, near vision, and contrast sensitivity measures do not reflect the visual difficulties encountered in common daily activities in our study population (Spearman correlation coefficients all less than 0.35). CONCLUSIONS: A few simple questions about visual function in common daily activities may give a clinician insights into patient complaints. It may be that environmental changes could improve self-reported visual function.

Neuropsychological (NP) functioning in first episode (FE) schizophrenia: A 2-year follow-up study

To examine the psychometric properties of a modified version of the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE), for a cardiac arrest population (IQCODE-CA).The IQCODE-CA, a 26-item observer-reported questionnaire, was completed by informants, defined as relatives or close friends, of 268 out-of-hospital cardiac arrest (OHCA) survivors who participated in the Target Temperature Management trial in a scheduled follow-up 180 ± 14 days after OHCA. Survivors completed the Mini Mental State Examination (MMSE), the Rivermead Behavioural Memory Test (RBMT) and the Hospital Anxiety and Depression Scale (HADS). An exploratory factor analysis was performed. Associations between IQCODE-CA results and demographic variables along with other instruments were calculated. Area under the curve (AUC) ratios were evaluated to examine discrimination.The IQCODE-CA measured one factor, global cognitive decline, with high internal consistency (ordinal α = 0.95). Age, gender or education did not influence the IQCODE-CA score. Associations with performance-based measures of global cognitive function as well as anxiety and depression ranged from small to moderate (rs = −0.29 to 0.38). AUC ratios ranged from fair to good (0.72–0.81). According to the MMSE and RBMT, the optimal cut-off score to identify cognitive decline on the IQCODE-CA was 3.04. Using this value, 53% of the survivors were under the cut-off.The IQCODE-CA identified a large amount of survivors with possible cognitive problems, making it useful when screening for cognitive decline post-CA. Due to lower AUC ratios than desired, additional performance-based measures should be used to improve the overall screening methodology.

Associations of performance-based and self-reported measures of visual function The Beaver Dam Eye Study

Objective : To describe and compare performance-based and self-reported measures of visual function and to evaluate how each varied with age and how the performance-based measures were associated with the responses to self-reported questions about visual function. Design : Population-based epidemiologic study. Participants : Adults participating in the first follow-up of the Beaver Dam Eye Study (n=3,722). Main outcome measures : Performance-based measures of vision including current binocular, best-corrected and near visual acuities, sensitivity to light as measured by an automated perimeter, contrast sensitivity, and self-reported measures from a standardized interview. Results : All performance-based and self-reported visual functions decreased with increasing age (p<0.0001 for each). On average, women did more poorly than men on all the performance-based measures (p<0.0001 for each), and on some of the self-reported measures. For both genders, correlations among the performance-based measures ranged from 0.38 to 0.67. In general, individuals reporting good visual function or little difficulty with visual tasks scored better on performance-based measures compared to individuals whose questionnaire responses reflected limited visual function. Overall, about 39% of drivers reported that their vision caused them to limit their night driving. Correlations of performance-based with self-reported measures of visual function were greater for best-corrected, binocular and near visual acuity compared to correlations of visual sensitivity to light and contrast sensitivity. There were 1,285 persons whose best-corrected acuity was better than their current binocular acuity and there were 97 people with visual impairment considering only current binocular acuity whose vision improved to better than 20/40 after refraction. Conclusions : Performance-based and self-reported measures of visual function were consistently and inversely related to age. Performance-based measures were, in general, more highly correlated between themselves than were self-reported measures. Self-reported visual functions were significantly positively correlated with all performance-based measures, but correlations were moderate. While high contrast measures are usually used in clinical settings and in many studies, the data suggest that in assessing function it is appropriate to measure several different aspects of vision, both performance-based and self-assessed. Our data give some indication of the impact these visual functions have on daily life as reflected by night driving and on near and distant visual acuity. New refractive corrections would likely improve the visual acuity in many older adults.

Lower Body Functioning as a Predictor of Subsequent Disability Among Older Mexican Americans

Disability measures among elderly non-Hispanic White populations have traditionally been associated with activities of daily living (ADLs) and instrumental activities of daily living (IADLs). More recently, performance-based measures have increasingly been used to predict the onset of disability in initially nondisabled elderly populations. We used data from two waves (1993-94 and 1995-96) of the Hispanic Established Populations for the Epidemiologic Studies of the Elderly (EPESE) to assess the degree with which lower mobility performance measures predict future disability in a representative sample of older Mexican Americans from the Southwestern United States. Performances on an 8-foot walk, repeated chair stands, and standing balance among nondisabled subjects at baseline were significantly associated with the onset of ADL and lower body disability 2 years later, controlling for age, gender, and the presence of medical conditions. The results were significant for each performance measure and for a measure combining all three. This study offers further evidence that performance-based measures of lower body function are able to predict future disability in older Mexican Americans, as has been found with other elderly populations. These measures were able to detect changes over a relatively short period of time (2 years). In addition, the study found that the short (8-foot) walk was the most sensitive measure in predicting future disability.

Performance-based and self-assessed measures of visual function as related to history of falls, hip fractures, and measured gait time: The beaver dam eye study

The purpose of the study is to report relationships between visual function parameters and falls, hip fractures, and gait time in adults. Population-based study. The 3722 persons who participated in the 5-year follow-up of the Beaver Dam Eye Study cohort. The visual functions measured at the examination were best-corrected visual acuity, current binocular acuity, near acuity, contrast sensitivity, and visual threshold to light. Information on falls and hip fractures was obtained by structured interview. Gait time was measured by standardized protocol. History of falls and hip fractures increased with age, as did time to walk a measured course. Falls were more commonly reported for all persons who had poorer visual function, although not all relationships were significant in persons less than 60 years of age. In persons 60 years of age and older, hip fractures after the age of 40 were significantly related to all measures of visual function. Time to walk a measured course was significantly related to all measures of visual function. These data indicate a consistent relationship between falls, fractures, gait time, and visual functions. Longitudinal data are necessary to accurately determine temporal relationships and to determine the likelihood of a causal association. In the interim, these data suggest that improving visual function may have benefits such as decreased traumatic events and improved mobility.

Correlates of performance-based measures of muscle function in the elderly: the Cardiovascular Health Study.

It is unknown how much age-related changes in muscle performance represent normal aging versus the effects of chronic disease and life style. We examined the correlates of four performance measures-gait speed, timed chair stands (TCS), grip strength, and maximal inspiratory pressure (MIP)-using baseline data from the Cardiovascular Health Study (CHS), a population-based study of risk factors for heart disease and stroke in persons > or = age 65. We analyzed data from the 5,201 CHS participants. Variables were arranged into nine categories: Personal Characteristics, Anthropometry, Physical Condition, Reported Functional Status, Subjective Health, Psychological Factors, Symptoms, Cognitive Status, Habits and Lifestyle, and Prevalent Disease. Independent correlates were identified using stepwise linear regression. The regression models explained 17.7-25.4% of the observed variability. Although age significantly correlated with each measure, it explained little of the variability (< or = 5.7%). Anthropometric features plus physical condition explained 14.0-17.4% of the variability for grip strength and MIP, but 2.8-12.9% of the variability for gait speed and the log of TCS. Subjective health and psychological factors explained 1.8-9.4% of the variability in gait speed and the log of TCS, but < or = 1.2% of the variability in grip strength and MIP. Variables for prevalent disease explained < or = 1.3% of the variability in each measure. After age 64, age explained little of the variability in muscle performance in a large sample of mostly functionally intact, community-dwelling older persons. Complex measures such as gait speed were more associated with subjective factors than were direct measures of strength. Prevalent disease contributed surprisingly little to muscle performance.

Age-related trends in cardiovascular morbidity and physical functioning in the elderly: the Cardiovascular Health Study.

To describe relationships between age and sub-clinical cardiovascular disease, manifest chronic disease, and physical functioning and limitations among persons aged 65 years and older, with emphasis on the "oldest old," those 85 years and older. Observational population-based study. Four U.S. communities: Forsyth County, North Carolina; Sacramento County, California; Washington County, Maryland; and Pittsburgh, Pennsylvania. 5,201 men and women aged 65 years and older. Demographic data; histories of cardiovascular disease (CVD), chronic lung disease, arthritis, diabetes, and hypertension; measures of subclinical disease including arm and ankle blood pressures, internal carotid wall thickness and stenosis, ejection fraction, left ventricular mass, fractional shortening, and diastolic function, electrocardiographic left ventricular hypertrophy and cardiac injury score, forced expiratory flow and volume; functional status including self-reported physical functioning, hearing and sight limitations and health status, and performance-based measures of function. These variables were examined among men and women in three age groups: 65-74 years, 75-84 years, and 85 + years. Subgroups of participants with and without manifest CVD were also examined. In women, the prevalence of CVD and other chronic conditions increased with age, and the highest rates occurred among those 85 years and older. In men, prevalence rates increased between the two younger groups, but the oldest group had lower than expected rates for coronary heart disease, cerebrovascular disease, hypertension, and chronic lung disease. In contrast, there were strong age-related linear trends in most of the subclinical measures of blood pressure, atherosclerosis and pulmonary function and in virtually all measures of functional status in both gender groups across the age range. There was a particularly marked decline in functional status between the two older age groups. While subclinical disease was greater and functional status was poorer among those with manifest CVD, with few exceptions, age-related trends were not significantly different between the two groups. Lower than expected prevalence rates of CVD among those aged 85 years and older, particularly among men, in this study of community-dwelling elderly may represent selection bias or a real plateauing in disease prevalence with age. However, subclinical disease appears to increase and functional status to decline across the age range in both men and women regardless of the presence of CVD. The apparent increase in subclinical disease with age indicates potential for CVD prevention after age 65.

The predictive validity of self-report and performance-based measures of function and health.

To learn about the value of self-report and performance-based measures of function in predicting mortality and institutionalization, we conducted a longitudinal study of 149 elderly persons at four sites (a senior citizens housing unit, two ambulatory-based geriatrics practices, and a board-and-care facility). At baseline, all subjects were administered a questionnaire containing Katz, Spector, and Rosow-Breslau scale items as well as the Mini-Mental State Exam and two performance-based measures, the Tinetti gait score and Physical Performance Test. At follow-up (average 22 months; range 17-29 months), 17 subjects (11%) had died and seven (5%) had been institutionalized. Univariate analysis demonstrated significant associations between death and all functional status measures. In logistic regression models, Katz items, Tinetti gait score, and the seven-item Physical Performance Test were independent predictors of "death or nursing home placement"; Katz items and the seven-item Physical Performance Test were independent predictors of mortality. These findings support the use of performance-based as well as self-report measures for clinical and research purposes.