An Investigation of Measurement Equivalence in Hearing Response Scales: Refinement of a Questionnaire for Use in Hearing Screening

Purpose Questionnaires used in hearing screening should be short and demonstrate measurement equivalence across groups defined by hearing impairment and hearing aid experience. The measurement equivalence of 2 scales addressing functionality (experienced hearing ability) and social hearing (social barriers due to hearing problems) was investigated. Method Measurement equivalence was assessed using the differential item functioning and differential test framework within item response theory. Three comparisons were considered: (a) persons with normal hearing versus persons with hearing impairment either owning or not owning a hearing aid; (b) hearing aid users versus individuals who do not use hearing aids; (c) hearing aid users versus persons with hearing impairment who do not use a hearing aid. A protocol of differential item detection was applied consisting of ordinal regression and the log-likelihood ratio test to flag suspect items, followed by applying the log-likelihood ratio test using anchor items ...