Approaches to Audiological Rehabilitation with Hearing Aids -studies on pre-fitting strategies and assessment of outcomes

Fourteen percent of the Swedish population report subjective hearing loss. The number of persons suffering from hearing loss is expected to increase in accordance with the increased length of the average life span, causing an associated increase in the demand for hearing health care services as new patient groups who expect a higher quality of life begin to request hearing care. The main goal of this thesis was to develop new approaches in audiological rehabilitation to meet these demands and achieve user satisfaction. Two randomized controlled trials including 39 and 38 subjects, respectively were performed that evaluated two interventions, user-controlled adjustment and sound awareness training, which were performed prior to a hearing aid fitting. The new approaches focused on increasing user participation and activity. To evaluate the goals of audiological rehabilitation, e.g., reducing auditory impairment, optimizing auditory activities and minimizing participation restrictions, several standardized self-reporting instruments were used to assess activity limitations, participation restriction, satisfaction and psychosocial well-being. Several of the instruments were validated for a Swedish population in a postal survey including 162 subjects. Furthermore, an interview instrument that was appropriate for telephone interviews and a categorization rating scale were developed for assessing the global clinical impression of the audiological rehabilitation. Few significant differences in outcomes were found between the treatment and control groups in the short term, and the interventions did not achieve additional or more successful hearing aid users in the long term. Thus, it was concluded that the hearing aid rehabilitation was effective in and of itself, as both the treatment and control groups showed significant improvements in psychosocial well-being and reduced activity limitation and participation restriction. The self-report instruments were found to be valid, and a factor analysis indicated that the number of questionnaires could be reduced with a recommendation for further clinical use. The telephone interviews evaluating the clinical global impression of the audiological rehabilitation were found to be effective and showed success in a vast majority of the users. Advantages such as simpler administration and less time consumption warrant their continued use in additional audiological settings. The pre-interventions in these studies need to be further investigated before they could be recommended for clinical use also in a Swedish context. The international standardized self reports, however, can already be recommended for clinical use. A first attempt to evaluate global clinical impression by telephone interviews was found to be effective and further validations are suggested. Original Papers This thesis is based on four original papers, referred to in the text by their Roman numerals IIV I Öberg M, Lunner T, Andersson G. Psychometric evaluation of hearing specific self-report measures and their associations with psychosocial and demographic variables. Audiological Medicine 2007;5:188-199. II Öberg M, Andersson G, Wänström G, Lunner, T. The effects of a pre-fitting intervention on hearing aid benefit: a randomized controlled trial. Submitted III Öberg M, Andersson G, Wänström G, Lunner, T. The effects of a sound awareness pre-fitting intervention: a randomized controlled trial. Audiological Medicine June 2008;6:129-140. IV Öberg M, Wänström G, Hjertman H, Lunner T, Andersson G. Development and initial validation of the “Clinical Global Impression” to measure outcomes for audiological rehabilitation. Accepted for publication in Disability and Rehabilation