The psychometric properties of the Childhood Health Assessment Questionnaire (CHAQ) in children with cerebral palsy

Application of Rasch Analysis for Development and Psychometric Properties of Adolescents' Quality of Life Instruments: A Systematic Review

BACKGROUND

Due to the importance of assessing quality of life (QoL) in healthy and ill adolescents, the evaluation of psychometric properties of these questionnaires is important.

OBJECTIVE

To investigate the application of Rasch analysis in psychometric assessment studies on adolescents' QoL instruments, and to evaluate the quality of reporting Rasch parameters in these studies.

METHODS

This systematic review was conducted by searching for papers in electronic databases PubMed, Web of Science, EMBASE, Cochrane Library and Scopus until December 2018.

RESULTS

After screening 122 papers, 31 remained in the study. Around 68% of the studies used the Rasch analysis for instrument testing and 32% for the development of new instruments. In 77.4% of studies, both classical and Rasch methods were used parallel to data analysis. In 32.2% of studies, healthy adolescents were the main target group. The most commonly used instrument in Rasch studies was, KIDSCREEN, administered in different countries. Six Rasch parameters were reported with a higher percentage in the studies. Major reported parameters of Rasch analysis were application of the software program (96.7%), test of item fit to the Rasch model (93.5%), unidimensionality (80.6%), type of the identified mathematical Rasch model (74.1%), threshold (58%) and differential item functioning (54.8%). Based on the psychometric evaluation of the QoL instruments, 71% of studies showed acceptable results.

CONCLUSION

The application of the Rasch model for psychometric assessment of adolescents' QoL questionnaires has increased in recent decades. But, there is still no strong and commonly used critical appraisal tool or guideline for the evaluation of these papers.

Rasch Analysis of the Disability Acceptance Scale for Individuals With Cerebral Palsy

Background: Acceptance of disability has been considered an important factor in rehabilitation procedures. The Disability Acceptance Scale (DAS) was used in a panel survey, and it is likely that this scale will be increasingly used. This study aimed to determine the psychometric characteristics of the DAS by applying a Rasch model, an application of item response theory.

Methods: Data were collected using the DAS with 84 individuals with cerebral palsy. The response data were analyzed for item fitness and item difficulty, rating scale fit, and reliability.

Results: Three of the nine DAS items had low fitness. Analysis of item difficulty showed that the item difficulty needs to be modified, suggesting the need to add some items with higher difficulty and some with lower difficulty. The 5-point Likert scale used in the evaluation questionnaires was not appropriate. An analysis of the six remaining items showed high levels of subject separation reliability and separation reliability of the items.

Conclusions: This study is significant because it identified the psychometric characteristics of the DAS through item response theory-based Rasch analysis and suggested the need to modify the item fitness and difficulty level. A modified six-item version of the DAS with a 4-point Likert scale was proposed as being more suitable.

The Rasch Analysis of Rosenberg Self-Esteem Scale in Individuals With Intellectual Disabilities

Background

The purpose of this study was to examine the psychometric properties of the Rosenberg Self-Esteem Scale for individuals with intellectual disabilities (ID) using the Rasch model and to determine whether the scale is valid and reliable for use with this population.

Methods

Rasch analysis was carried out on data from 223 respondents to the 8th Panel Survey on Employment for the Disabled conducted by the Korea Employment Agency for the Disabled. The validity and reliability of scale items were verified through analyses of item fit, item difficulties, the rating scale, and separation indices.

Results

Item infit mean square values were found to range between 0.71 and 1.25, and item outfit mean square values between 0.71 and 1.26. Additionally, item difficulties were appropriate; Item 4 was the most difficult item, while Item 10 was the easiest item. The 4-point rating scale was appropriate, and the separation indices were at an acceptable level.

Conclusion

Based on these results, the validity and reliability of the Rosenberg Self-Esteem Scale for use with individuals with ID were verified. Thus, this scale can be regarded as a useful tool for evaluating the level of self-esteem of individuals with ID.