Leigh Lehman

A comparison of the ability of two upper extremity assessments to measure change in function.

STUDY DESIGN Retrospective Measurement Comparison. INTRODUCTION Upper extremity musculoskeletal disorders affect millions, thus, discerning optimal assessments for measuring change in upper extremity function is critical. PURPOSE OF THE STUDY To compare responsiveness (ability to measure change) of the Disabilities of Arm, Shoulder, and Hand (DASH) and Upper Extremity Functional Index (UEFI). METHODS Statistical analyses included Rasch analysis to place the instruments on the same scale, analysis of variance to compare change scores, correlations to compare change scores with global ratings, and the use of receiver operating characteristic (ROC) curves to determine meaningful change scores and overall error. RESULTS Change scores on the DASH and UEFI and correlations between change scores and global ratings were similar. Areas under the ROC curves for the DASH and UEFI were 67% and 65%, respectively. CONCLUSIONS Neither assessment has a clear advantage over the other when measuring clinical change. LEVEL OF EVIDENCE Not applicable.

Ability to Detect Change in Patient Function: Responsiveness Designs and Methods of Calculation

UNLABELLED In hand clinics, the goal of enabling patient improvement is fostered by the use of assessments with the ability to detect change (responsiveness). Thus, for commonly used assessments, investigations are needed to determine a standardized change index, the amount of change exceeding error estimates (minimal detectable change or MDC), and the amount of change shown to make a clinically relevant difference (clinically important difference or CID). The purpose of study was to serve as an introduction for hand therapists to responsiveness designs and indices and to highlight their application within the clinical setting. The study design used was a narrative review. Method papers and research studies addressing responsiveness were selected and summarized. Currently, several good studies of responsiveness have been conducted. However, there is a need to move beyond the calculation of standardized change indices to include the calculation of clinically meaningful values. For many of the assessments used in hand clinics, there is still a call for investigation of the amount of change, which exceeds error estimates (MDC) and the amount of change shown to make a clinically relevant difference (CID). LEVEL OF EVIDENCE N/A.

Utilizing Rasch measurement models to develop a computer adaptive self-report of walking, climbing, and running

Purpose. The purpose of this paper is to show how the Rasch model can be used to develop a computer adaptive self-report of walking, climbing, and running. Method. Our instrument development work on the walking/climbing/running construct of the ICF Activity Measure was used to show how to develop a computer adaptive test (CAT). Fit of the items to the Rasch model and validation of the item difficulty hierarchy was accomplished using Winsteps software. Standard error was used as a stopping rule for the CAT. Finally, person abilities were connected to items difficulties using Rasch analysis ‘maps’. Results. All but the walking one mile item fit the Rasch measurement model. A CAT was developed which selectively presented items based on the last calibrated person ability measure and was designed to stop when standard error decreased to a pre-set criterion. Finally, person ability measures were connected to the ability to perform specific walking/climbing/running activities using Rasch maps. Conclusions. Rasch measurement models can be useful in developing CAT measures for rehabilitation and disability. In addition to CATs reducing respondent burden, the connection of person measures to item difficulties may be important for the clinical interpretation of measures.

Influence of Fear-Avoidance Beliefs on Functional Status Outcomes for People With Musculoskeletal Conditions of the Shoulder

Background The influence of elevated fear-avoidance beliefs on change in functional status is unclear. Objective The purpose of this study was to determine the influence of fear-avoidance on recovery of functional status during rehabilitation for people with shoulder impairments. Design A retrospective longitudinal cohort study was conducted. Methods Data were collected from 3,362 people with musculoskeletal conditions of the shoulder receiving rehabilitation. At intake and discharge, upper-extremity function was measured using the shoulder Computerized Adaptive Test. Pain intensity was measured using an 11-point numerical rating scale. Completion rate at discharge was 57% for function and 47% for pain intensity. A single-item screen was used to classify patients into groups with low versus elevated fear-avoidance beliefs at intake. A general linear model (GLM) was used to describe how change in function is affected by fear avoidance in 8 disease categories. This study also accounted for within-clinic correlation and controlled for other important predictors of functional change in functional status, including various demographic and health-related variables. The parameters of the GLM and their standard errors were estimated with the weighted generalized estimating equations method. Results Functional change was predicted by the interaction between fear and disease categories. On further examination of 8 disease categories using GLM adjusted for other confounders, improvement in function was greater for the low fear group than for the elevated fear group among people with muscle, tendon, and soft tissue disorders (Δ=1.37, P<.01) and those with osteopathies, chondropathies, and acquired musculoskeletal deformities (Δ=5.52, P<.02). These differences were below the minimal detectable change. Limitations Information was not available on whether therapists used information on level of fear to implement treatment plans. Conclusions The influence of fear-avoidance beliefs on change in functional status varies among specific shoulder impairments.

Development of an item bank for a computerised adaptive test of upper-extremity function.

Purpose. The purpose of this study was to determine the psychometric characteristics of an upper-extremity item bank as a precursor to developing a computer adaptive patient reported outcome instrument. The Activity dimension of the World Health Organizations International Classification of Functioning, Disability and Health (ICF) provided the conceptual framework for the items. Method. Factor and Rasch analyses were used to evaluate the psychometric properties of the item bank, including: monotonicity, local independence, dimensionality, item difficulty hierarchy and match between sample ability and item difficulty. Results. Monotonicity of the rating scale was supported. Nine item pairs were locally dependent, and thus one item from each pair was removed from subsequent analyses. There was evidence for two unidimensional constructs; gross upper-extremity and fine hand. Both constructs showed good internal consistency and person separation. In general, the order of item difficulty within each construct replicated the hypothesised item difficulty order. The fine hand construct had a ceiling effect. Conclusions. The above study of our newly developed upper-extremity item bank empirically verified the intended item difficulty order, identified separate constructs (i.e. gross upper-extremity and fine hand) and provided insights into eliminating the ceiling effect of one of the constructs. These findings are critical precursors to the development of upper-extremity components of the ICF Activity Measure, an ICF-based, CAT located on the web at: www.icfmeasure.phhp.ufl.edu.

Global rating of change: perspectives of patients with lumbar impairments and of their physical therapists

ABSTRACT Background: Global rating of change (GROC) scores provide a means of measuring patients’ self-perceived change in health status over time. Objectives: The purposes of the study were to examine agreement of GROC ratings between the patient (GROCp) and the treating therapist (GROCt), the impact on the minimal clinically important difference (MCID) estimates by reporting resources, and the relationships between the subjective GROC scores and objective outcome measures. Methods: Data from 52,767 patients with orthopedic lumbar spine impairments treated in 623 outpatient rehabilitation clinics in 34 states (United States) were analyzed. Patient’s functional status (FS) before and after the treatment was measured using the Lumbar Computerized Adaptive Testing (LCAT) survey (0–100 scale). The GROC ratings were obtained from both the patients and their caring therapists at discharge. Results: On average, GROCp (mean [(SD] = 3.1 [4.1]) was 1.9 points lower than GROCt (mean [SD] = 5.0 [1.9]). There were negligible differences between MCID estimates derived from the patients’ GROC ratings (MCID cutoff = 9.2) and from the therapists’ GROC ratings (MCID cutoff = 9.5). While only analyzing patient data whose GROCp ≥ 0, the intraclass correlation coefficient between GROCp and GROCt was 0.61, the GROCp correlated with FS at intake at r = 0.12, with FS at discharge at r = 0.56, and with FS change scores at r = 0.47. Conclusions: Therapists tended to report higher GROC ratings than their patients did but there were negligible differences between MCID estimates derived from GROCp and that derived from GROCt.

Quality of Life Perspectives of People With Amyotrophic Lateral Sclerosis and Their Caregivers

This study explored differences in perspectives on quality of life (QOL) between people affected by amyotrophic lateral sclerosis (ALS) and their caregivers. QOL is often thought of as related to physical limitations, without consideration of other factors (e.g., cognitive, emotional) that may be stronger predictors of QOL in people with long-term degenerative diseases. Because QOL is complex and influenced by multiple factors, people with ALS and their caregivers may have different perspectives on what constitutes QOL. This study investigated potential discrepancies in QOL perspectives between people with ALS and their caregivers. Thirty dyads from the Augusta University Health ALS Clinic completed a measure of QOL, and we compared the results and identified patterns. The most prominent finding was that members of the dyads misunderstood the mental experiences of one another.

Differential Item Functioning in a Computerized Adaptive Test of Functional Status for People with Shoulder Impairments is Negligible across Pain Intensity, Gender, and Age Groups:

People with shoulder impairments (N = 3,767) reported upper extremity function using a 37-item shoulder-specific computerized adaptive test (shoulder CAT). The authors determined whether items of the shoulder CAT have differential item functioning (DIF) by pain intensity (low and high), gender (men and women), and age groups (young-adult, middle-aged and old-adult). They assessed whether items have uniform and/or non-uniform DIF using an ordinal logistic regression and item response theory approaches and applied large and small DIF criteria to assess the magnitude of DIF. The analyses revealed that uniform DIF was absent in all 37 items. Only six items exhibited non-uniform DIF using the large DIF criterion. Adjusting the person-ability measures for DIF had minimal practical impact on the overall measure of shoulder function estimated using the shoulder CAT. The shoulder CAT provided a precise measurement of function without discriminating for pain intensity, gender, and age among patients referred to rehabilitation with shoulder impairment.

Rasch Analysis of the Activities-Specific Balance Confidence Scale in Older Adults Seeking Outpatient Rehabilitation Services

• BACKGROUND: The Activities‐specific Balance Confidence (ABC) scale measures confidence in performing various ambulatory activities without falling or experiencing a sense of unsteadiness. • OBJECTIVES: This study (1) examined the ABC scale (0‐100) using Rasch analysis, (2) assessed statistically reliable change, and (3) developed a functional staging to guide clinical interpretation of a patients improvement. • METHODS: The authors examined rating‐scale structure, item difficulty hierarchy, item fit, person‐item match, separation index, differential item functioning, test precision, and unidimensionality. Additionally, this cross‐sectional study of 5012 older patients seeking outpatient rehabilitation therapy in 123 clinics estimated the minimal detectable change and developed a functional staging. • RESULTS: The item “walk outside on icy sidewalks” was the most difficult item, while the item “reach for a small can off a shelf at eye level” was the easiest item. Overall, average patient ability estimates of 56.2 ± 20.3 were slightly higher than the average item difficulty estimates of 45.9 ± 7.8. With a separation index equal to 3.65, the ABC scale items can differentiate individuals into 5.2 statistically distinct strata. Most ABC scale items were free of differential item functioning. For example, “walk outside on icy sidewalks” was easier for patients who were underweight. Results supported unidimensionality of the ABC scale, with the first factor explaining 77% of the total variance. The estimated minimal detectable change was 15 points. The authors provided an example of functional staging application. • CONCLUSION: Results supported sound psychometric properties and clinical usage of the ABC scale for older adults seeking outpatient rehabilitation therapy.