Performance-based Measures Of Function Research Articles

The Impact of Visual Field Clusters on Performance-based Measures and Vision-Related Quality of Life in Patients With Glaucoma

To investigate how visual field (VF) clusters affect performance-based measures of the ability to perform activities of daily living and subjective measures of vision-related quality of life (QoL) in patients with glaucoma. Prospective, cross-sectional study. setting: Institutional - Wills Eye Hospital. 322 eyes of 161 patients with moderate-stage glaucoma. VF tests were conducted using the Humphrey 24-2 Swedish Interactive Thresholding Algorithm standard perimeter. The VFs of each patient were divided into 5 clusters: nasal, temporal, central, paracentral, and peripheral. The score for each cluster was the averaged total deviation scores of all tested points within the cluster. Each cluster score was correlated with performance-based measures of visual function and subjective assessment of vision-related QoL. The Compressed Assessment of Ability Related to Vision, the National Eye Institute Visual Functioning Questionnaire 25 (NEI VFQ-25), and the Modified Glaucoma Symptom Scale. The central VF cluster in the better eye was positively correlated with all Compressed Assessment of Ability Related to Vision (performance-based measure) subscales. The strongest correlation for the better eye was between the central VF cluster and total Compressed Assessment of Ability Related to Vision score (0.39, P < .001). The inferior VF hemisphere in both eyes was positively correlated with most Compressed Assessment of Ability Related to Vision subscales. Central VF clusters in the better eye were positively correlated with a majority of the NEI VFQ-25 subscales. There were no significant correlations between VF clusters and Modified Glaucoma Symptom Scale subscales. Scores of central VF defects in the better eye and inferior hemisphere defects in both eyes were positively correlated with performance-based measures of the ability to perform activities of daily living. Glaucoma patients with central defects in the better eye were more likely to have reduced scores on assessments of vision-related QoL.

Factor structure and aetiological architecture of the BRIEF: A twin study.

Executive function is a broad construct that encompasses various processes involved in goal-directed behaviour in non-routine situations (Banich, 2009). The present study uses a sample of 560 5- to 16-year-old twin pairs (M=11.14, SD=2.53): 219 monozygotic twin pairs (114 female; 105 male) and 341 dizygotic twin pairs (136 female, 107 male; 98 opposite sex) to extend prior literature by providing information about the factor structure and the genetic and environmental architecture of the Behavior Rating Inventory of Executive Function (BRIEF; Gioia etal., 2000, Child Neuropsychol., 6, 235; Gioia etal., 2000, Behavior rating inventory of executive function, Lutz, FL: Psychological Assessment Resources), a multifaceted rating scale of everyday executive functions. Phenotypic results revealed a 9-scale, 3-factor model best represents the BRIEF structure within the current sample. Results of the genetically sensitive analyses indicated the presence of rater bias/contrast effects for the Initiate, Working Memory, and Task-Monitor scales. Additive genetic and non-shared environmental influences were present for the Initiate, Plan/Organize, Organization of Materials, Shift, and Monitor and Self-Monitor scales. Influences on Emotional Control were solely environmental. Interestingly, the aetiological architecture observed was similar to that of performance-based measures of executive function. This observed similarity provided additional evidence for the usefulness of the BRIEF as a measure of 'everyday' executive function.

Parent-report and performance-based measures of executive function assess different constructs

A total of 405 children of 5–18 years of age were administered performance-based and parent-report measures of executive function (EF), and measures of motor, attention, reading, and mathematics performance. Attention, reading, and mathematics abilities were associated with a parent-report measure of EF. Reading and mathematics abilities were also associated with performance-based measures of EF, including the Animal Sorting, Inhibition, and Response Set subtests of the Developmental NEuroPSYchological Assessment-II. In contrast, motor functioning was only associated with performance-based measures of EF. Findings suggest that different constructs of EF are measured by parent-report versus performance-based measures, and that these different constructs of EF are associated with different neurodevelopmental processes.

Hip abductor strength in people with knee osteoarthritis: A cross-sectional study of reliability and association with function

BackgroundTo investigate the clinical importance of hip abductor (HA) strength in people with knee osteoarthritis (OA), the purposes of this study were to 1) compare the association of HA strength and physical function to that of knee extensor (KE) strength and physical function, and 2) determine the reliability of the assessment of HA strength using a hand-held dynamometer. MethodsThirty-five individuals [58 years standard deviation 10 years old] with knee osteoarthritis participated. Physical function was assessed with performance-based [Get-Up and Go (GUG), stair climb and descent (SC), and five times chair rise (CR)] and self-reported (WOMAC function) measures. The relationship between strength and function was assessed using bivariate correlation and hierarchical multiple regression models. Reliability across sessions was assessed in 25 subjects. ResultsIn the bivariate models, both KE and HA strength were both significantly associated with performance-based measures of function, but not WOMAC function. After controlling for anthropometric factors and KE strength in the hierarchical models, HA made significant independent contributions to the prediction of GUG and SC, but not CR or WOMAC function. The reliability of HA strength was excellent (ICC2, 3=0.94; 95% CI=0.86–0.97), while the minimum detectable change (MDC95) was 0.29Nm/kg (95% CI=0.23–0.41). ConclusionHA strength can be reliably measured and is closely associated with functional performance in people with knee OA. Clinical RelevanceThese results provide preliminary evidence suggesting that HA strength may be an important rehabilitation target for the conservative management of knee OA.

Pre-operative Functional Parameters of Patients Undergoing Total Knee Arthroplasty.

Total knee arthroplasty (TKA) has become the gold standard to manage pain and disability associated with knee osteoarthritis (KOA). There are no clear criteria on to determine when or who should undergo TKA. The creation of a pre-operative profile that includes physical functional data may aid in the clinical decision-making for the timing of TKA. Aim 1: to observe the pre-operative functional profile of subjects with advanced KOA and to depict it according to gender. Aim 2: to assess the association between pain, self-reported and performance-based physical function outcomes. retrospective study. Physical functional data from 122 persons (89 women and 33 men) with end-stage KOA were obtained through a database. Data consisted of height, weight, 6-minute walk test (6MWT) and the deficit when compared with normative values, self-visual analogue scale (VAS) after 6MWT and Western Ontario and McMaster Universities Index (WOMAC). Descriptive statistics were used to report the observed data; student t-test and Mann-Whitney were used to compare gender groups. Spearman correlation was used to asses the association with the 6MWT, WOMAC and VAS. The mean (standard deviation) values of our sample for the WOMAC, 6MWT deficit and VAS were calculated. There was a significant difference between gender in the WOMAC score and pain intensity (VAS) after the 6MWT (p = 0.002; p = 0.01). Moderate to weak correlations between WOMAC score, VAS and 6MWT were found. Correlation values ranged from r = 0.23 to 0.48. The current study suggests a functional profile for subjects who are scheduled to undergo TKA. Our results show that the correlations of self-report and performance-based measures of function and reported pain are poor. This enhances the idea of using all of these types of measures to establish the functional profile a sample of subjects with advanced KOA. Copyright © 2015 John Wiley & Sons, Ltd.

Predictive validity and responsiveness of patient-reported and performance-based measures of function in the Boston RISE study.

Patient-reported and performance-based measures (PBMs) are commonly used to measure physical function in studies of older adults. Selection of appropriate measures to address specific research questions is complex and requires knowledge of relevant psychometric properties. The aim of this study was to examine the predictive validity for adverse outcomes and responsiveness of a widely used patient-reported measure, the Late-Life Function and Disability Instrument (LLFDI), compared with PBMs. We analyzed 2 years of follow-up data from Boston RISE, a cohort study of 430 primary care patients aged ≥65 years. Logistic and linear regression models were used to examine predictive validity for adverse outcomes and effect size and minimal detectable change scores were computed to examine responsiveness. Performance-based functional measures included the Short Physical Performance Battery, 400-m walk, gait speed, and stair-climb power test. The LLFDI and PBMs showed high predictive validity for poor self-rated health, hospitalizations, and disability. The LLFDI function scale was the only measure that predicted falls. Absolute effect size estimates ranged from 0.54 to 0.64 for the LLFDI and from 0.34 to 0.63 for the PBMs. From baseline to 2 years, the percentage of participants with a change ≥ minimal detectable change was greatest for the LLFDI scales (46-59%) followed by the Short Physical Performance Battery (44%), gait speed (35%), 400-m walk (17%), and stair-climb power test (9%). The patient-reported LLFDI showed comparable psychometric properties to PBMs. Our findings support the use of the LLFDI as a primary outcome in gerontological research.

Assessment of Upper Extremity Function in Multiple Sclerosis: Review and Opinion

Upper extremity (UE) dysfunction may be present in up to ˜80% of individuals with multiple sclerosis (MS), although its importance may be under-recognized relative to walking impairment, which is the hallmark symptom of MS. Upper extremity dysfunction affects independence and can impact the ability to use walking aids. Under-recognition of UE dysfunction may result in part from limited availability of performance-based and patient self-report measures that are validated for use in MS and that can be readily incorporated into clinical practice for screening and regularly scheduled assessments. In addition to the 9-Hole Peg Test, which is part of the Multiple Sclerosis Functional Composite, there are several performance-based measures that are generally used in the rehabilitation setting. These measures include the Box and Block Test, the Action Research Arm Test, the Test d'Evaluation de la performance des Membres Supérieurs des Personnes Agées, and the Jebsen-Taylor Test of Hand Function. Several of these measures were developed for use in stroke, although in contrast to stroke, which is characterized by unilateral dysfunction, UE impairment in MS is generally bilateral, and should be assessed as such. Similarly, patient-reported UE measures are available, including Disabilities of the Arm, Shoulder, and Hand (DASH) and its shorter version, QuickDASH, the Manual Ability Measure, and ABILHAND, although none has been psychometrically validated for MS. Recently, item response theory was used to develop a Neuro-QOL (Quality of Life) UE measure and a Patient-Reported Outcomes Measurement Information System UE measure; neither of these have demonstrated sensitivity to change, limiting their use for longitudinal assessment. Consequently, although work is still needed to develop and validate performance-based and patient-reported measures of UE function that are suitable for use in daily MS clinical practice, currently available UE measures can be recommended for incorporation into MS management, albeit with an understanding of their limitations.

Knee Function Assessment in Patients With Meniscus Injury: A Preliminary Study of Reproducibility, Response to Treatment, and Correlation With Patient-Reported Questionnaire Outcomes.

Background:Outcomes of meniscus surgery are typically assessed with patient questionnaires that help capture symptoms and functional limitations but may not provide an accurate representation of underlying joint health. There are currently no performance-based measures of knee function in patients with symptomatic meniscus injury.Purpose:To assess the reproducibility, response to partial meniscectomy, and correlation with patient-reported questionnaire outcomes of novel performance-based knee function tests.Study Design:Cohort study (diagnosis); Level of evidence, 2.Methods:A battery of 9 tests for activities that require knee movements essential for everyday living was developed. Intra- and interrater reproducibility was assessed in 50 meniscus tear patients completing the battery at 2 preoperative assessments with either the same or different examiners. Response to arthroscopic partial meniscectomy was evaluated in 35 of these patients 6 weeks after surgery. Subjects also completed the Knee Injury and Osteoarthritis Outcome Score (KOOS) and International Knee Documentation Committee (IKDC) questionnaires pre- and postoperatively.Results:The intrarater intraclass correlation coefficients (ICCs) were excellent for all tests (ICC > 0.8). Interrater ICC > 0.8 was observed for step-down, stair descent, star lunges, and timed treadmill travel. Performance on all tests improved significantly with surgery (P < .05), with the greatest improvement in sit-to-stand and stair ascent and descent. A greater percentage response to surgery was seen on questionnaire outcomes (20%-65%) than on performance-based tests (3%-15%). Moderate to poor correlations existed between the KOOS activities of daily living subscale and the performance-based tests (all ICCs ≤ 0.4).Conclusion:Performance-based knee function tests demonstrated good reproducibility and responsiveness in patients undergoing partial meniscectomy.Clinical Relevance:As both patient perception and functional performance are determinants of patient outcomes, questionnaires and performance-based tests could be used simultaneously to provide complementary data to monitor short- and long-term outcomes after meniscus surgery.

Functional outcomes after surgical management of articular cartilage lesions in the knee: a systematic literature review to guide postoperative rehabilitation.

Systematic literature review. To systematically review the literature relative to muscle performance, knee joint biomechanics, and performance-based functional outcomes following articular cartilage repair and restoration surgical procedures in the knee. Articular cartilage injuries are associated with functional limitations, poor quality of life, and the potential for long-term disability. This review systematically evaluates evidence related to muscle performance, joint biomechanics, and performance-based functional outcomes following articular cartilage procedures, and discusses their implications for rehabilitation. The online databases of PubMed (MEDLINE), CINAHL, SPORTDiscus, and Scopus were searched (inception to September 2013). Studies pertaining to muscle performance, knee joint biomechanics, and performance-based measures of function following articular cartilage procedure in the knee were included. Sixteen articles met the specified inclusion criteria. Seven studies evaluated muscle performance, all showing persistent deficits in quadriceps femoris muscle strength for up to 7 years postprocedure. Quadriceps femoris strength deficits of greater than 20% were noted in 33% and 26% of individuals at 1 and 2 years following microfracture and autologous chondrocyte implantation (ACI), respectively. Two studies evaluated knee mechanics post-ACI, showing persistent deficits in knee kinematics and kinetics for up to 12 months postprocedure compared to uninjured individuals. Seven studies showed improved functional capacity (6-minute walk test) over time, and 3 studies showed persistent performance deficits during higher-level activities (single-leg hop test) for up to 6 years postprocedure. Five studies comparing weight-bearing protocols (accelerated versus traditional/current practice) following ACI found few differences between the groups in function and gait mechanics; however, persistent gait alterations were observed in both groups compared to uninjured individuals. Significant quadriceps femoris strength deficits, gait deviations, and functional deficits persist for 5 to 7 years following ACI and microfracture surgical procedures. Future research regarding rehabilitation interventions to help mitigate these deficits is warranted. Level of Evidence Prognosis, level 2a-.

Ten‐Year Effects of the Advanced Cognitive Training for Independent and Vital Elderly Cognitive Training Trial on Cognition and Everyday Functioning in Older Adults

To determine the effects of cognitive training on cognitive abilities and everyday function over 10 years. Ten-year follow-up of a randomized, controlled single-blind trial (Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE)) with three intervention groups and a no-contact control group. Six U.S. cities. A volunteer sample of 2,832 persons (mean baseline age 73.6; 26% African American) living independently. Ten training sessions for memory, reasoning, or speed of processing; four sessions of booster training 11 and 35 months after initial training. Objectively measured cognitive abilities and self-reported and performance-based measures of everyday function. Participants in each intervention group reported less difficulty with instrumental activities of daily living (IADLs) (memory: effect size = 0.48, 99% confidence interval (CI) = 0.12-0.84; reasoning: effect size = 0.38, 99% CI = 0.02-0.74; speed of processing: effect size = 0.36, 99% CI = 0.01-0.72). At a mean age of 82, approximately 60% of trained participants, versus 50% of controls (P < .05), were at or above their baseline level of self-reported IADL function at 10 years. The reasoning and speed-of-processing interventions maintained their effects on their targeted cognitive abilities at 10 years (reasoning: effect size = 0.23, 99% CI = 0.09-0.38; speed of processing: effect size = 0.66, 99% CI = 0.43-0.88). Memory training effects were no longer maintained for memory performance. Booster training produced additional and durable improvement for the reasoning intervention for reasoning performance (effect size = 0.21, 99% CI = 0.01-0.41) and the speed-of-processing intervention for speed-of-processing performance (effect size = 0.62, 99% CI = 0.31-0.93). Each Advanced Cognitive Training for Independent and Vital Elderly cognitive intervention resulted in less decline in self-reported IADL compared with the control group. Reasoning and speed, but not memory, training resulted in improved targeted cognitive abilities for 10 years.

Older patients/older donors: choosing wisely

Two lingering problems regarding transplantation in older adults have been how to select patients appropriately and whether to use older sibling donors. Allogeneic hematopoietic cell transplantation (HCT) of older patients may result in long-term survival due to GVL, but the data remain observational and mostly restricted to those 50 to 69 years of age. Patients with excellent performance status and low comorbidity have the best long-term survival after HCT. Novel measures of health status such as self-report or performance-based functional measures allow “staging the age” and may inform candidacy for less robust patients. Older matched sibling donors should be preferred over matched unrelated donors (MUDs) because outcomes are equivalent to superior for matched sibling donors compared with MUD. However, MUDs also achieve acceptable outcomes and long-term disease control. An alternative donor can be considered based on institutional protocols and expertise. Very limited information is available in patients or related donors 70 years of age and older. Future efforts to more completely characterize patient health status before transplantation will allow better application of HCT in older adults.

Older patients/older donors: choosing wisely

Two lingering problems regarding transplantation in older adults have been how to select patients appropriately and whether to use older sibling donors. Allogeneic hematopoietic cell transplantation (HCT) of older patients may result in long-term survival due to GVL, but the data remain observational and mostly restricted to those 50 to 69 years of age. Patients with excellent performance status and low comorbidity have the best long-term survival after HCT. Novel measures of health status such as self-report or performance-based functional measures allow "staging the age" and may inform candidacy for less robust patients. Older matched sibling donors should be preferred over matched unrelated donors (MUDs) because outcomes are equivalent to superior for matched sibling donors compared with MUD. However, MUDs also achieve acceptable outcomes and long-term disease control. An alternative donor can be considered based on institutional protocols and expertise. Very limited information is available in patients or related donors 70 years of age and older. Future efforts to more completely characterize patient health status before transplantation will allow better application of HCT in older adults.

Common and specific cognitive deficits in schizophrenia: relationships to function.

The goals of the present study were to assess the interrelationships among tasks from the MATRICS and CNTRACS batteries, to determine the degree to which tasks from each battery capture unique variance in cognitive dysfunction in schizophrenia, and to determine the ability of tasks from each battery to predict functional outcome. Subjects were 104 schizophrenia patients and 132 healthy control subjects recruited as part of the CNTRACS initiative. All subjects completed four CNTRACS tasks and two tasks from the MATRICS battery: Brief Assessment of Cognition in Schizophrenia Symbol Coding and the Hopkins Verbal Learning Test. Functional outcome was also assessed in the schizophrenia subjects. In both the patient and control groups, we found significant intercorrelations between all higher order cognitive tasks (episodic memory, goal maintenance, processing speed, verbal learning) but minimal relationships with the visual task. For almost all tasks, scores were significantly related to measures of functional outcome, with higher associations between CNTRACS tasks and performance-based measures of function and between one of the MATRICS tasks and self-reported functioning, relative to the other functioning measures. After regressing out variance shared by other tasks, we continued to observe group differences in performance among task residuals, particularly for measures of episodic memory from both batteries, although these residuals did not correlate as robustly with functional outcome as raw test scores. These findings suggest that there exists both shared and specific variance across cognitive tasks related to cognitive and functional impairments in schizophrenia and that measures derived from cognitive neuroscience can predict functional capacity and status in schizophrenia.

Essential tremor 10, 20, 30, 40: clinical snapshots of the disease by decade of duration

Essential tremor (ET) is a chronic, progressive neurological disorder in which disease burden may slowly accrue. There are few long-term studies, and the clinical and functional status of patients, with each decade of disease duration, has not been documented in detail. We used cross-sectional data on 335 patients with ET (disease duration 1-81 years) to produce clinical snapshots of the disease at each 10-year milestone (i.e. < 10, 10-19, 20-29, 30-39, ≥ 40 years). We hope these data will be of value in clinical-prognostic settings both to patients and their treating physicians. In this cross-sectional, clinical-epidemiological study at Columbia-University Medical Center, each patient underwent a single evaluation, including self-reported measures of tremor-related disability, performance-based measures of function, and neurologist-assessments of tremor type, location and severity. A variety of metrics of tremor severity increased across the 10-year time intervals. By ≥ 40 years duration, one-third of patients had tremor in at least two cranial locations (neck, voice, jaw), and the proportion with high-amplitude tremor reached 20.3% (while drawing spirals), 33.8% (spilling while drinking) and 60.8% (spilling while using a spoon). Yet even in the longest tremor duration group, very few (< 10%) were incapacitated (i.e. completely unable to perform the above-mentioned tasks), and one-third continued to exhibit no cranial tremor. These data paint a picture of progressive decade-by-decade decline in ET. Yet patients with long disease duration did not relentlessly converge at the same end-stage of severe, functionally incapacitating, diffuse tremor. In this respect, long-duration ET patients presented a heterogeneous picture.

Stroke‐specific executive function assessment: A literature review of performance‐based tools

Executive function should be an integral component of post-stroke assessment. However, a Canada-wide survey of occupational therapists on stroke rehabilitation practices found a rare use of executive function assessments. Performance-based executive function assessments that closely reflect real-world activities are useful in identifying individuals who will face difficulties when returning to home and community activities. To increase clinicians' awareness of these tools, a literature review was conducted to identify performance-based measures of executive function and their stroke-specific psychometric properties. The review identified 17 performance-based tools and 41 studies that reported their psychometric properties specific to stroke. Each tool was critically appraised according to the executive function components assessed, the level of functioning assessed (i.e. impairment, activity or participation), the environment within which the assessment is conducted and the tool's psychometric properties and clinical utility. Standard criteria were used to evaluate the tools' psychometric properties. The findings were compiled in a Stroke-Specific Executive Function Toolkit. The assessments that demonstrated the strongest evidence of reliability and validity were the Executive Function Performance Test, the Multiple Errands Test and the Assessment of Motor and Process Skills. Only the Assessment of Motor and Process Skills has been adequately evaluated for its ability to detect change. In terms of clinical utility, the Kettle Test has the shortest administration time (i.e. less than 20 minutes) and requires limited equipment. CONCLUSIONS AND SIGNIFICANCE OF THE STUDY: The Stroke-Specific Executive Function Toolkit provides clinicians with useful information that should facilitate identification of appropriate executive function tools for use across the continuum of stroke care.

Malnutrition is related to functional impairment in older adults receiving home care.

The aims of this work were (a) to provide a detailed description of the association between nutritional (Mini Nutritional Assessment; MNA®) and functional status in a sample of older adults receiving home care, using both questionnaire- and performance-based functional methods, and (b) to investigate the impact of different MNA subscales on this association. Multi-centre, cross-sectional. Home care. 296 persons ≥65 years in need of care (80.7±7.7 y). Nutritional status was determined by the MNA and functional status by two questionnaires (Instrumental and Basic Activities of Daily Living; IADL, ADL) and three performance tests (handgrip strength, HGS; Short Physical Performance Battery, SPPB; Timed 'Up and Go' Test, TUG). A categorical and a covariance analytical approach were used to test for differences in functional status between MNA groups (well nourished, risk of malnutrition, malnourished). In addition, functional parameters were correlated with total MNA, a modified MNA version (modMNA), where functional items were excluded, and MNA subscales ('functionality', 'general assessment', 'anthropometry', 'dietary assessment', and 'subjective assessment'). 57% of the participants were at risk of malnutrition and 12% malnourished. 35% reported severe limitations in IADL, 18% in ADL. 40%, 39% and 35% had severe limitations in HGS, SPPB and TUG; 9%, 28% and 34% were not able to perform the tests. Functional status deteriorated significantly from the well nourished to the malnourished group in all functional measures. The modMNA was weak but still significantly related to all functional parameters except TUG. The subscale 'functionality' revealed strongest correlations with functional measures. All other MNA subscales showed only weak or no associations. More than one half of the seniors receiving home care were at nutritional risk and poor functional level, respectively. Malnutrition according to MNA was significantly associated to both questionnaire- and performance-based functional measures even after exclusion of functional MNA items.

Normalized Knee-Extension Strength or Leg-Press Power After Fast-Track Total Knee Arthroplasty: Which Measure Is Most Closely Associated With Performance-Based and Self-Reported Function?

ObjectiveTo investigate which of the 2 muscle-impairment measures for the operated leg, normalized knee extension strength or leg press power, was most closely associated with performance-based and self-reported measures of function shortly after total knee arthroplasty (TKA). DesignCross-sectional, exploratory study. SettingLaboratory at a regional hospital. ParticipantsIndividuals (N=39) with an average age ± SD of 65.5±10.3 years, who all had unilateral TKA 28 days prior. InterventionsNone. Main Outcome MeasuresThe patients performed maximal isometric knee extensions and dynamic leg presses to determine their body-mass normalized knee extension strength and leg press power, respectively. The 10-meter fast speed walking- and 30-second chair stand tests were used to determine performance-based function, while the Western Ontario and McMaster Universities Osteoarthritis Index and Oxford Knee Scores were used to determine self-reported function. ResultsNormalized leg press power was more closely associated with both performance-based (r=.82, P<.001) and self-reported (r=.48, P=.002) measures of function compared with normalized knee extension strength (r=.51, P=.001 and r=.39, P=.015, respectively). ConclusionsNormalized leg press power was more closely associated with both performance-based and self-reported function early after TKA than normalized knee extension strength. It may be explained by the fact that performance-based measures of function are typically closed kinetic chain tasks, such as walking or rising from a chair, and self-reported measures of function typically include questions that address perceived difficulty with performing these same tasks.

The relationship between cognitive function and life space: The potential role of personal control beliefs.

We examined the relationship of cognitive and functional measures with life space (a measure of spatial mobility examining extent of movement within a person's environment) in older adults, and investigated the potential moderating role of personal control beliefs. Internal control beliefs reflect feelings of competence and personal agency, while attributions of external control imply a more dependent or passive point of view. Participants were 2,737 adults from the ACTIVE study, with a mean age of 74 years. Females comprised 76% of the sample, with good minority representation (27% African American). In multiple regression models controlling for demographic factors, cognitive domains of memory, reasoning, and processing speed were significantly associated with life space (p < .001 for each), and reasoning ability appeared most predictive (B = .117). Measures of everyday function also showed significant associations with life space, independent from the traditional cognitive measures. Interactions between cognitive function and control beliefs were tested, and external control beliefs moderated the relationship between memory and life space, with the combination of high objective memory and low external control beliefs yielding the highest life space (t = -2.07; p = .039). In conclusion, older adults with better cognitive function have a larger overall life space. Performance-based measures of everyday function may also be useful in assessing the functional outcome of life space. Additionally, subjective external control beliefs may moderate the relationship between objective cognitive function and life space. Future studies examining the relationships between these factors longitudinally appear worthwhile to further elucidate the interrelationships of cognitive function, control beliefs, and life space.

What is the Rate of Functional Improvement During Occupational Rehabilitation in Workers’ Compensation Claimants?

We examined the rate of functional change (using performance measures and a self-report questionnaire) during interdisciplinary occupational rehabilitation in workers' compensation claimants with a variety of musculoskeletal conditions. We also estimated the rate of improvement that could be considered clinically important and examined factors associated with rate of functional improvement. A prospective cohort design was used, with data collected before and after claimants participated in an interdisciplinary occupational rehabilitation program. A consecutive sample was formed of claimants admitted between July 2005 and June 2007. Measures included performance-based functional measures (functional capacity evaluation, FCE) and a self-report questionnaire (pain disability index, PDI). The sample included 582 compensation claimants with a variety of musculoskeletal conditions. The majority of claimants experienced functional improvement during rehabilitation. Claimants with the outcome status 'Return-to-Work Pre-accident' had the highest rate of functional change (up to 5 kg/week on floor to waist lifting, ~7 points/week on the PDI). The clinically important rate of functional change appears to be 5 kg/week on FCE floor-to-waist lifting and 7 points/week on the PDI (scored out of 100). Rate of functional change appears to be multifactorial, with a variety of physical, demographic, clinical, and environmental factors explaining rate of change.

Performance-Based Versus Patient-Reported Physical Function: What Are the Underlying Predictors?

Functional limitations have been operationally defined for studies of rehabilitation science through measures of physical performance and patient-reported function. Although conceived as representing similar concepts, differences between these 2 modes of measuring physical functioning have not been adequately characterized scientifically. The purpose of this study was to compare the Short Physical Performance Battery (SPPB) with the function component of the Late-Life Function and Disability Instrument (LLFDI) with respect to their association with physiologic factors and other psychosocial and health factors potentially influencing rehabilitative care. This study was a cross-sectional analysis of baseline data from a sample of community-dwelling older adults (N=137) with mobility limitations enrolled in a randomized controlled trial of exercise. A performance-based measure of function (the SPPB) and a self-report measure of function (the LLFDI) served as functional outcomes. Physiologic factors included measures of leg strength, leg velocity, and exercise tolerance test (ETT) duration, which served as a surrogate measure of aerobic capacity. Psychosocial and health factors included age, sex, height, body mass index, number of chronic conditions, depression, and falls efficacy. Separate multivariable regression models predicting SPPB and LLFDI scores described 33% and 42% of the variance in each outcome (R(2)), respectively. Leg velocity and ETT duration were positively associated with both performance-based and patient-reported functional measures. Leg strength and age were positively associated with SPPB scores, whereas number of chronic conditions, sex, and falls efficacy were associated with the LLFDI scores. This study included older adults with mobility limitations and may not generalize to other populations. Performance-based and patient-reported measures of physical function appear to assess different aspects of an older person's functioning. The SPPB was associated with age and physiologic factors, whereas patient-reported function measured by the LLFDI was associated with these factors as well as with psychosocial and health factors.