Bhagwant S. Sindhu

Validity, Reliability, and Responsiveness of a Digital Version of the Visual Analog Scale

UNLABELLED The design used in this study was a prospective cohort. Pain intensity levels recorded by the digital version of the visual analog scale (VAS-D) are easy to both score and share with other health care professionals. The purpose of the study was to examine the test-retest reliability, concurrent validity, and responsiveness of the VAS-D. Thirty-three people with upper extremity injuries reported pain intensity levels before and after performing four maximal grip contractions (pre- and postgripping). Our version of the VAS-D had high test-retest reliability (r=0.96) and good concurrent validity (r=0.84-0.97) with both the paper version of the VAS (VAS-P) and the verbal numerical rating scale (NRS-V). Responsiveness of the VAS-D was indicated by a significant increase in pain levels from pre- to postgripping. Similar responsiveness to that of the VAS-P and NRS-V was indicated by similar effect size coefficients and analysis of variance of pain change scores. In conclusion, the VAS-D is a reliable, valid, and responsive measure of pain intensity for people with upper extremity injuries. However, differences in accuracy (resolution) among the VAS-D, VAS-P, or NRS-V may render the three pain scales not fully compatible. LEVEL OF EVIDENCE Not applicable.

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.

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.

Using the Force–Time Curve to Determine Sincerity of Effort in People with Upper Extremity Injuries

UNLABELLED This was a prospective cohort study. In a previous study, the slopes of the force-time (F-T) curve were shown to differentiate between maximal and submaximal grip effort in healthy participants. The objective of the study was to examine if the slopes of the F-T curve can determine the sincerity of effort in people with upper extremity injuries. Forty participants with unilateral upper extremity injury performed maximal and submaximal grip efforts. The F-T curve was recorded, and the slopes of the force-generation and force-decay phases were calculated. Repeated-measures analysis of variance revealed significantly steeper slopes for maximal than those for submaximal efforts. However, receiver operating characteristic curves showed that, at best, the slope of the force-generation phase yielded overall error rates of 55% for women and 60% for men. Therefore, sensitivity and specificity values were insufficient to effectively differentiate maximal from submaximal efforts. The slopes of the F-T curve did not validly measure the sincerity of effort in participants with upper extremity injury, perhaps, because they were protective of their injured hand and, thus, exerted only submaximal effort even at their best grip attempt. LEVEL OF EVIDENCE Not applicable.

Identifying Sincerity of Effort Based on the Combined Predictive Ability of Multiple Grip Strength Tests

STUDY DESIGN Retrospective Cohort. INTRODUCTION Detecting sincerity of effort (SOE) of grip strength remains a frustrating and elusive task for hand therapists because there are no valid, reliable, or widely accepted assessments for identifying feigned effort. Some therapists use various combinations of different SOE tests in an attempt to identify feigned effort, but there is lack of evidence to support this practice. PURPOSE The present study examined the ability of a combination of three grip strength tests commonly used in the clinic to detect SOE: the five rung grip test, rapid exchange grip test, and coefficient of variation. A secondary purpose was to compare the predictive ability between the logistic and linear regression models. METHODS Healthy participants (n=146) performed the three SOE tests exerting both maximal and submaximal efforts. We compared the ability of two regression models, the logistic and linear models, to predict sincere versus insincere efforts. RESULTS Combining the three tests predicted SOE better than each test alone. Yet, the full logistic model, which was the best predictor of SOE, explained only 42% of variance and correctly classified only 58% of the efforts. CONCLUSIONS Our findings do not support the clinical practice of combining these three tests to detect SOE. LEVEL OF EVIDENCE Not applicable.

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.

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.

Hand-Grip Strength: Normative Reference Values and Equations for Individuals 18 to 85 Years of Age Residing in the United States

• BACKGROUND: Hand‐grip strength is an indicator of overall strength and a predictor of important outcomes. Up‐to‐date, population‐specific reference values for measurements of grip strength are needed to properly interpret strength outcomes. • OBJECTIVES: To provide population‐based grip‐strength reference values and equations for US residents 18 to 85 years of age. • METHODS: Hand‐grip data from 1232 participants 18 to 85 years of age were extracted from the database of the 2011 normative phase of the US National Institutes of Health Toolbox project in this cross‐sectional study. Descriptive reference values and equations were derived from the data. • RESULTS: The authors present grip‐strength reference values using summary statistics (mean, standard deviation, and percentile). The mean grip strength ranged from 49.7 kg for the dominant hand of men 25 to 29 years of age to 18.7 kg for the nondominant hand of women 75 to 79 years of age. The researchers also present reference regression equations for the dominant and nondominant sides of men and women. The explanatory variables in the equations are age, height, and weight. • CONCLUSION: The normative reference values and equations provided in this study may serve as a guide for interpreting grip‐strength measurements obtained from tested individuals. • KEY WORDS: grip, hand, hand strength, NIH Toolbox (health care), norm