Developing a common metric using current scales for assessing functioning in patients with knee osteoarthritis.

Objectives: Various scales exist to assess different domains of functioning in knee osteoarthritis (OA). This study aimed to explore whether it is possible to develop a common metric (CM) from the frequently used scales to assess functioning in knee OA. Patients and methods: The methodological study evaluated 411 patients (81 males, 330 females; mean age: 61.8±10.5 years; range, 41 to 88 years) with knee OA. Data from the Health Assessment Questionnaire, Oxford Knee Score, Medical Outcomes Study Short Form 36, Knee Injury and Osteoarthritis Outcome Score, Western Ontario and McMaster Universities Arthritis Index, and the Nottingham Health Profile were used, and the items focusing on self-care, mobility, and domestic activity domains based on the activities and participation component of the International Classification of Functioning, Disability, and Health were included. Concurrent calibration was performed to combine the items of the scales. The CM parameters were estimated using the Rasch measurement model. Reliability was assessed using the person separation index. The CM was utilized to generate a transformation table to convert the scale scores to each other based on the reference metric score. Results: Each scale fitted the Rasch model. Item invariance was achieved for the CM (p=0.775). The CM had a person separation index of 0.827. Age, sex, and disease duration did not cause difference in item functions. The CM satisfied the assumptions of unidimensionality and local independence. Conclusion: A reliable CM was created from the commonly used scales to measure functioning in individuals with knee OA. Thus, clinicians and researchers can refer to the transformation table to directly compare scores of those scales and use them interchangeably.

Validation of the Pediatric Quality of Life Inventory 3.0 Cerebral Palsy Module (Parent Form) for use in Türkiye.

Objectives: This study was planned to test the reliability and validity of the Turkish version of the Pediatric Quality of Life Inventory (PedsQL) 3.0 cerebral palsy (CP) module (parent form) in children with CP. Patients and methods: In the validation study conducted between June 2007 and June 2009, 511 children (299 normal children, 212 children with CP) were assessed by the seven scales of PedsQL [daily activities (DA), school activities (SA), movement and balance (MB), pain and hurt (PH), fatigue (F), eating activities (EA), and speech and communication (SC)]. Reliability was tested by internal consistency and person separation index (PSI); internal construct validity by Rasch analysis and external construct validity by correlation with the Gross Motor Function Classification System (GMFCS) and Functional Independence Measure for Children (WeeFIM). Results: Only 13 children with CP completed the inventory by themselves and thus were excluded. Consequently, 199 children with CP (113 males, 86 females; mean age: 7.3±4.2 years; range, 2 to 18 years) and 299 normal children (169 males, 130 females; mean age: 9.4±4.0 years; range, 2 to 17 years) were included in the final analysis. Reliabilities of the seven scales of the PedsQL 3.0 CP module were adequate, with Cronbach's alphas between 0.66 and 0.96 and the PSI between 0.672 and 0.943 for the CP group. In Rasch analysis, for each scale, items showing disordered thresholds were rescored; then testlets were created to overcome local dependency. Internal construct validity of the unidimensional seven scales was good with the mean item fit of -0.107±1.149, 0.119±0.818, 0.232±1.069, -0.442±0.672, 0.221±0.554, -0.091±0.606, and -0.333±1.476 for DA, SA, MB, PH, F, EA, and SC, respectively. There was no differential item functioning. External construct validity of the instrument was confirmed by expected moderate to high correlations with WeeFIM and GMFCS (Spearman's r=0.35-0.89). Conclusion: Turkish version of the PedsQL 3.0 CP module is reliable, valid, and available for use in clinical setting to evaluate health-related quality of life of children with CP.

Effectiveness of pulsed electromagnetic field therapy in the management of complex regional pain syndrome type 1: A randomized-controlled trial.

Objectives: This study aims to investigate whether pulsed electromagnetic field (PEMF) therapy in addition to a conventional rehabilitation program is effective on pain and functioning in patients with type 1 complex regional pain syndrome (CRPS-1) of the hand. Patients and methods: Between March 2013 and January 2015, a total of 32 patients (16 males, 16 females; mean age: 50.1±13.1 years; range, 25 to 75 years) were included. The patients were randomly allocated into two groups. The control group (n=16) received a conventional rehabilitation program consisting of physical modalities, exercises, and occupational therapy, whereas the PEMF group (n=16) received additional PEMF (8 Hz, 3.2 mT) to the affected hand. The primary outcome measure was pain intensity using the Numeric Rating Scale (NRS). Secondary outcome measures were grip and pinch strength, hand edema, hand dexterity, and hand activities. All patients received 20 therapy sessions (five sessions/week, four weeks in total) and were evaluated before and after the therapy and at the first-month follow-up. Results: Both groups showed significant improvements in primary and secondary outcomes (p<0.05) after the therapy and at follow-up. When the groups were compared in terms of improvements in assessment parameters, no statistically significant difference was found between the two groups in any of the outcomes (p>0.05). Conclusion: The PEMF in addition to conventional rehabilitation program did not provide additional benefit for pain and hand functions in CRPS-1. Future studies using different application parameters such as frequency, intensity, duration, and route may provide a better understanding of the role of PEMF in CRPS-1 treatment.

Is it possible to develop a new measurement tool to assess the functional status in patients with rheumatoid arthritis?

OBJECTIVES: This study aims to develop measurement tools for assessing patients' functional status with rheumatoid arthritis (RA) in terms of upper and lower extremity function and to evaluate the tools' construct validities with classical and modern psychometric approaches. PATIENTS AND METHODS: Between April 2010 and April 2012, a total of 300 patients with RA (77 males, 223 females; mean age: 52.3±11.5 years; range, 18 to 82 years) who answered items from a range of widely used instruments were included. After examining initial dimensionality with exploratory factor analysis (EFA), confirmatory factor analysis (CFA), and Rasch analysis were used to evaluate the tools' construct validities. The data-model fit was evaluated with goodness-of-fit (GoF) statistics in CFA, while the tools were examined in terms of item and person fit, unidimensionality and differential item functioning (DIF) from the perspective of Rasch analysis. RESULTS: According to EFA, two dimensions were identified and named as "self-care-mobility-household activities related to lower extremity" and "self-care-mobility-household activities related to upper extremity" taking into account the factor loadings and the clinical classifications. While the clinical classification was tested with CFA, all items were loaded on their pre-defined dimensions with the factor loadings of ≥0.40 and GoF statistics were within the acceptable ranges. When the "self-care-mobility-household activities related to upper extremity" and "self-care-mobility-household activities related to lower extremity" tools were evaluated via the Rasch analysis, both tools were found to fit the Rasch model expectations, with a mean item fit statistics of -0.528 logit (standard deviation [SD]: 1.365) and -0.213 (SD: 1.168; mean person fit statistics of -0.412 logit (SD: 1.160) and -0.303 logit (SD: 0.859), respectively. CONCLUSION: For the evaluation of a scale's construct validity, it is recommended to use the Rasch analysis in tandem with factor analytic methods, as the Rasch analysis explores a scale's construct validity in terms of item and person fit, DIF and unidimensionality which is the only aspect of the factor analysis.

Does extracorporeal shock wave therapy decrease spasticity of ankle plantar flexor muscles in patients with stroke: A randomized controlled trial.

OBJECTIVE: To evaluate the effectiveness of radial extracorporeal shock wave therapy on ankle flexor spasticity in stroke survivors and to reveal changes in the fibroelastic components of muscle. DESIGN: Randomized controlled trial. SETTING: Inpatient neuro-rehabilitation clinic of a university hospital. PARTICIPANTS: Stroke patients with ankle flexor spasticity. INTERVENTIONS: Patients were randomized to three groups; radial extracorporeal shock wave therapy, sham, or control. Active and sham therapy were administered two sessions/week for two weeks. All patients received conventional rehabilitation. MAIN MEASURES: The primary outcome was Modified Ashworth Scale. Secondary outcomes were the Tardieu Scale and elastic properties of plantar flexor muscles assessed by elastography (strain index). All assessments were performed before, immediately after the treatment, and four weeks later at follow-up. RESULTS: Fifty-one participants were enrolled (active therapy n = 17, sham n = 17, control n = 17). Modified Ashworth scores showed a significant decrease in the active therapy group (from 2.47 ± 0.72 to 1.41 ± 0.62) compared to sham (from 2.19 ± 1.05 to 2.06 ± 1.12) and control (from 2.06 ± 0.85 to 2.00 ± 0.73) groups immediately after the treatment (P < 0.001). Tardieu results were also in concordance (P < 0.001), however this effect was not preserved at follow-up. Elastic properties of the ankle flexors were improved in all groups at both assessments after the therapy showing significant decreases in strain index (P < 0.001). However, there was no difference among the groups in terms of improvement in elastography. CONCLUSION: Radial extracorporeal shock wave therapy has short-term anti-spastic effects on ankle flexor muscles when used as an adjunct to conventional rehabilitation.

Is there a relationship between venous insufficiency and knee osteoarthritis?

OBJECTIVES: This study aims to evaluate whether there is a relationship between venous insufficiency (VI) and knee osteoarthritis (OA). PATIENTS AND METHODS: Between February 2012 and May 2013, a total of 206 knees of 103 participants (14 males, 89 females; mean age 48.6±8.6 years; range, 30 to 69 years) were enrolled. The study group included 59 patients who were diagnosed with knee OA and the control group included 44 healthy volunteers without any complaint in their knee joints. Demographic and clinical characteristics of all participants were recorded. Venous system of the lower extremities was evaluated by Doppler ultrasonography. All knees were evaluated using conventional radiography based on the Kellgren-Lawrence (K&L) grading system and ultrasonography. Pain severity was evaluated using Likert pain scale and functioning was evaluated using Western Ontorio and McMaster Universities Osteoarthritis Index (WOMAC). RESULTS: Venous insufficiency was detected in 40.6% of the OA group and 15.9% of the control group (p=0.007). There was no statistically significant difference in the cartilage thicknesses and K&L grading regarding the presence of VI (p>0.05); however, the percentage of the radiographic medial tibial sclerosis was higher in patients with VI (60%) in the OA group (p>0.05). The WOMAC total scores were similar in both groups, while the WOMAC pain scores were higher in the patients with deep VI (p>0.05). CONCLUSION: Increased radiographic medial tibial sclerosis and higher WOMAC pain scores in patients with venous involvement in OA may lead to the hypothesis that venous system pathologies can affect the intraosseous microenvironment of the bone, resulting in pain and early subchondral bone involvement, consequently presenting as subchondral sclerosis.

Analyzing differential item functioning of the Nottingham Health Profile by Mixed Rasch Model.

OBJECTIVES: This study aims to evaluate whether items in the Turkish version of the Nottingham Health Profile (NHP) function differently according to age, sex, and duration of pain using the Mixed Rasch Model (MRM). PATIENTS AND METHODS: The NHP data of patients with low back pain from a previous study was analyzed. To analyze differential item functioning (DIF) within the items of the NHP, the MRM was used. Age, sex, and duration of pain were considered factors which could cause DIF. The most powerful factor to define latent classes derived from the MRM was estimated using the Rasch tree method. RESULTS: The two-class mixture version of the nominal response model was identified as the best fitting model for the physical mobility, sleep, and social isolation sections. For the physical mobility dimension, some items showed DIF by age and for the social isolation dimension some items showed DIF by sex. For the sleep dimension, latent classes were unable to be explained by age, sex, and duration of pain. Items in other dimensions of the NHP were DIF-free and no items showed DIF according to age, sex, and duration of pain. CONCLUSION: The results of this study may shed light on explaining the different response behavior of patients on the items of the NHP. Age and sex were found to be variables affecting item responses of NHP. Contrary to expectations, duration of pain did not cause DIF for any item. From the perspective of DIF, it can be concluded that NHP scale is a robust scale in terms of validity.

Integrating patient reported outcome measures and computerized adaptive test estimates on the same common metrics: an example from the assessment of activities in rheumatoid arthritis.

AIM: This study aimed to explore the potential of an inclusive and fully integrated measurement system for the Activities component of the International Classification of Functioning, Disability and Health (ICF), incorporating four classical scales, including the Health Assessment Questionnaire (HAQ), and a Computerized Adaptive Testing (CAT). METHODS: Three hundred patients with rheumatoid arthritis (RA) answered relevant questions from four questionnaires. Rasch analysis was performed to create an item bank using this item pool. A further 100 RA patients were recruited for a CAT application. Both real and simulated CATs were applied and the agreement between these CAT-based scores and 'paper-pencil' scores was evaluated with intraclass correlation coefficient (ICC). Anchoring strategies were used to obtain a direct translation from the item bank common metric to the HAQ score. RESULTS: Mean age of 300 patients was 52.3 ± 11.7 years; disease duration was 11.3 ± 8.0 years; 74.7% were women. After testing for the assumptions of Rasch analysis, a 28-item Activities item bank was created. The agreement between CAT-based scores and paper-pencil scores were high (ICC = 0.993). Using those HAQ items in the item bank as anchoring items, another Rasch analysis was performed with HAQ-8 scores as separate items together with anchoring items. Finally a conversion table of the item bank common metric to the HAQ scores was created. CONCLUSION: A fully integrated and inclusive health assessment system, illustrating the Activities component of the ICF, was built to assess RA patients. Raw score to metric conversions and vice versa were available, giving access to the metric by a simple look-up table.

An application of computerised adaptive testing for measuring health status in patients with knee osteoarthritis.

PURPOSE: The aim of this study was to explore the potential of computerised adaptive testing (CAT) for measuring health status in knee osteoarthritis. METHOD: Three hundred and fifty-one patients with knee osteoarthritis (OA) answered 118 questions from a range of widely used questionnaires. Three dimensions relevant to knee OA were identified by expert opinion as 'pain, mental and emotional status'; 'self-care and household activities' and 'mobility and social activities'. Confirmatory factor analysis (CFA) was used to test the relationship between the items and their dimensions. After CFA, these dimensions were subjected to Rasch analysis to calibrate the items onto an interval scale. A CAT was developed for each dimension, and the results checked against simulated applications from 10,000 simulees. RESULTS: After CFA and Rasch analysis, 14, 22 and 23 items remained in the first, second and third dimensions, respectively. Items were mostly free of differential item functioning for age, gender and duration of disease. Reliability exceeded 0.87 for each dimension. The health status levels generated using item banks and those obtained from the simulated CAT application were highly correlated (i.e. >0.91 for each dimension). On average, 8, 10 and 10 items were used to estimate the health status levels using the CAT for the first, second and third dimensions respectively. CONCLUSIONS: Using a combination approach of CFA and Rasch analysis, this study has shown that it is possible to calibrate items onto a single metric in a way that can be used to provide the basis of a CAT application.