Refinement and Validation of the Empowerment Audiology Questionnaire: Rasch Analysis and Traditional Psychometric Evaluation
Authors: Bennett Rebecca J. , Larsson Josefina , Gotowiec Sarah , Ferguson Melanie 
Published: December 2023

Objectives:
Empowerment is the process through which individuals with hearing-related challenges acquire and use knowledge, skills and strategies, and increase self-efficacy, participation, and control of their hearing health care, hearing solutions, and everyday lives. The aim was to refine and validate the Empowerment Audiology Questionnaire (EmpAQ), a hearing-specific measure of empowerment. This was achieved through (1) refinement via Rasch analysis (study 1), and (2) traditional psychometric analysis of the final survey structure (study 2).

Design:
In study 1, 307 adult hearing aid owners completed the initial empowerment measure (33 items) online. To inform an intended item reduction, Rasch analysis was used to assess a range of psychometric properties for individual items. The psychometric properties included analysis of individual items (e.g., response dependency, fit to the polytomous Rasch model, threshold ordering) and the whole EmpAQ (e.g., dimensionality). Item reduction resulted in a 15-item version (EmpAQ-15) and a short-form 5-item version (EmpAQ-5), validated using modern (Rasch), and traditional (Classical Test Theory) psychometric analysis (study 2). In study 2, 178 adult hearing aid owners completed the EmpAQ-15 and EmpAQ-5, alongside 5 questionnaires to measure related constructs. These included two hearing-specific questionnaires (Social Participation Restrictions Questionnaire and Self-Assessment of Communication), two general health-related questionnaires (Patient Activation Measure and World Health Organization Disability Assessment Schedule 2.0), and a general empowerment questionnaire (Health Care Empowerment Questionnaire). Modern (Rasch) and traditional psychometric analysis techniques (internal consistency, construct validity, and criterion validity) were used to assess the psychometric properties of the EmpAQ-15 and EmpAQ-5.

Results:
Rasch analysis of the initial 33-item measure of empowerment identified 18 items with high response dependency, poor fit to the Rasch model, and threshold disordering, which were removed, resulting in a long-form (EmpAQ-15) hearing-specific measure of empowerment. A short-form (EmpAQ-5) version was developed for use in the clinic setting. Validation of the two EmpAQ measures using Rasch analysis showed good item fit to the Rasch model, appropriate threshold targeting, and the existence of unidimensionality. Traditional psychometric evaluation showed that both questionnaires had high internal consistency and positive correlations with the hearing-specific questionnaires. However, in contrast with our hypotheses, correlations with general health questionnaires were stronger than with hearing-specific questionnaires; all questionnaires were correlated with the EmpAQ and in the direction hypothesized. Taken together, these findings support the construct validity of the EmpAQ-15 and EmpAQ-5.

Conclusions:
The EmpAQ-15 and EmpAQ-5 are the first self-report measures to be developed specifically for the measurement of empowerment. The EmpAQ-15 and EmpAQ-5 were found to meet the Rasch model criteria for interval-level measurements. Traditional psychometric evaluation supports the construct validity of both measures. The EmpAQ measures have the potential to be used in both research and clinical practice to evaluate empowerment along the hearing journey. The next stage of this research will be to further validate these measures by assessing their responsiveness, minimal clinically important difference, and clinical interpretability in a clinical population.