Applying Rasch analysis to evaluate measurement equivalence of different administration formats of the Activity Limitation scale of the Cambridge Pulmonary Hypertension Outcome Review (CAMPHOR)

Using the interviewer-administered version of Work Rehabilitation Questionnaire (WORQ) in Russia: cross-cultural adaptation and psychometric properties in traumatic spinal cord injury

PURPOSE

(1) To perform a cross-cultural adaptation of Work Rehabilitation Questionnaire to Russian (WORQ-R); (2) to report the psychometric properties of WORQ-R in patients with traumatic spinal cord injury (TSCI).

MATERIALS AND METHODS

WORQ is designed to evaluate the work functioning of individuals who are engaged in vocational rehabilitation. We performed a formal cross-cultural adaptation of WORQ from English to Russian utilizing a standardized 3-step approach. We examined the psychometric properties of WORQ-R in terms of its reliability and construct validity through the use of classical and modern test theory in the TSCI population.

RESULTS

The adaptation process achieved equivalence between Russian and English versions of WORQ. WORQ-R proved to cover major issues concerning functioning in vocational rehabilitation and was simple to understand. The internal consistency of WORQ-R was good (Cronbach's Alpha = 0.83). Rasch analysis confirmed the unidimensionality of the WORQ-scale and high reliability (PSI = 0.97) based on a testlet solution. WORQ-R score showed a strong negative correlation with the Functional Independence Measure, moderate negative correlation with the Spinal Cord Independence Measure Version III and the SF-36, moderate positive correlation with the Spinal Cord Injury Secondary Conditions Scale.

CONCLUSIONS

WORQ-R showed good validity and reliability in persons with TSCI allowing vocational professionals to have comprehensive information on vocational functioning.IMPLICATIONS FOR REHABILITATIONSCI is a disabling condition that causes impairments in body structure and function leading to activity limitations and participation restrictions.WORQ is a generic tool that allows for an assessment of work-related aspects of functioning in different populations of persons with disabilities.This study demonstrates the psychometric properties of the Russian version of WORQ in the SCI population.WORQ-R is recommended as a tool to describe the biopsychosocial and related vocational background to gain a better understanding of needs among SCI persons in terms of vocational rehabilitation.

German translation, cultural adaption and validation of the unidimensional self-efficacy scale for multiple sclerosis: a study protocol

INTRODUCTION

Self-efficacy refers to individuals' confidence in their ability to perform relevant tasks to accomplish desired goals. This is independent of their actual abilities. In people with multiple sclerosis (MS), self-efficacy has been shown to powerfully influence motivation and health-related behaviour, such as adherence to prescribed treatment or physical activity. So far, a rigorously tested German language self-efficacy questionnaire for people with MS is missing.

METHODS

The purpose of this study is to translate the original Unidimensional Self-Efficacy Scale for Multiple Sclerosis (USE-MS) into German and to validate the German USE-MS (USE-MS-G). Based on Bandura's concept of self-efficacy and international guidelines for questionnaire development, the patient-led development of the pre-final German version will involve a forward-backward translation process, synthesis of translations, expert committee review and consensus with the original test developers. At two centres in Tyrol, Austria, content and face validity and cultural adaption for Austria will be established using face-to-face semistructured cognitive interviews of 30 people with MS (PwMS). A further 292 PwMS with minimal to severe disability will be tested at two timepoints to validate the USE-MS-G.

RESULTS

Mixed methods analyses will be applied. Interviews will be transcribed and analysed employing qualitative content analysis. External validity will be explored using Spearman's Rank correlation coefficients of the USE-MS-G with the 13-item Resilience Scale, General Self-Efficacy Scale, Multiple Sclerosis International Quality of Life questionnaire, Hospital Anxiety and Depression Scale and MS-specific Neurological Fatigue Index. Test-retest reliability, internal consistency and floor and ceiling effects will be evaluated. Internal validity will be examined using Rasch analysis.

ETHICS AND DISSEMINATION

Ethical approval was received from the Ethics Committee of the Medical University of Innsbruck, Austria (reference number EK1260/2018; 13.12.2018). Results from this study will be disseminated to the participants and MS Societies, and to clinicians and researchers through peer-reviewed publications and conferences.

STUDY REGISTRATION

ISRCTN Registry; trial ID ISRCTN14843579; prospectively registered on 02. 01. 2019; http://www.isrctn.com/ISRCTN14843579.

Assessing the equivalence of Web-based and paper-and-pencil questionnaires using differential item and test functioning (DIF and DTF) analysis: a case of the Four-Dimensional Symptom Questionnaire (4DSQ)

PURPOSE

Many paper-and-pencil (P&P) questionnaires have been migrated to electronic platforms. Differential item and test functioning (DIF and DTF) analysis constitutes a superior research design to assess measurement equivalence across modes of administration. The purpose of this study was to demonstrate an item response theory (IRT)-based DIF and DTF analysis to assess the measurement equivalence of a Web-based version and the original P&P format of the Four-Dimensional Symptom Questionnaire (4DSQ), measuring distress, depression, anxiety, and somatization.

METHODS

The P&P group (n = 2031) and the Web group (n = 958) consisted of primary care psychology clients. Unidimensionality and local independence of the 4DSQ scales were examined using IRT and Yen's Q3. Bifactor modeling was used to assess the scales' essential unidimensionality. Measurement equivalence was assessed using IRT-based DIF analysis using a 3-stage approach: linking on the latent mean and variance, selection of anchor items, and DIF testing using the Wald test. DTF was evaluated by comparing expected scale scores as a function of the latent trait.

RESULTS

The 4DSQ scales proved to be essentially unidimensional in both modalities. Five items, belonging to the distress and somatization scales, displayed small amounts of DIF. DTF analysis revealed that the impact of DIF on the scale level was negligible.

CONCLUSIONS

IRT-based DIF and DTF analysis is demonstrated as a way to assess the equivalence of Web-based and P&P questionnaire modalities. Data obtained with the Web-based 4DSQ are equivalent to data obtained with the P&P version.