Measuring the Outcomes of a National Rehabilitation Program : Normative Data for the Client Oriented Scale of Improvement (COSI) and the Hearing Aid User's Questionnaire (HAUQ)

Self-report outcome measures were routinely collected from 4421 adult clients around Australia . The measures used were the Hearing Aid User's Questionnaire (HAUQ), which assessed hearing aid use, benefit, problems, and satisfaction, and the Client Oriented Scale of Improvement (COSI), which identified client needs, change in listening ability, and final listening ability in situations important to each client . Listening to television or radio and conversing with one or two others in a quiet place were the most frequently nominated needs . The benefit reported for noisy places was less than for quiet places, but very positive nonetheless . The normative data collected show a marked concentration of responses near the upper end of the scale for each of the outcome items except daily use . Consequently, correlations between the measures, although highly significant, were mostly less than 0.4. When the data were collapsed across subjects seen at each hearing center, benefit, satisfaction, usage, and problems with the hearing aids became much more strongly correlated with each other, with correlation coefficients up to 0.8 . Benefit, satisfaction, usage, and the types of problems clients encountered with their hearing aids varied significantly from hearing center to hearing center. The most frequently reported problem was dissatisfaction with the quality of the subjects' own voices (i .e ., occlusion effect), followed by feedback. The problems most closely related to usage, benefit, and satisfaction, however, were the presence of feedback, comfort of the earmold or earshell, and the quality of the users' own voices . These outcome measures appear to be most suitable for identifying needs, identifying individuals receiving markedly less than average benefit, and for finding small differences between outcomes for subgroups of the population .