Current criteria used to determine eligibility for rehabilitative hearing services (particularly device fitting) in Australia focus heavily on audiometric thresholds. However, studies into the predictors of benefit from hearing aid fitting show that while pure tone thresholds do predict help-seeking behaviours, they do not strongly predict the benefit that users receive.
This study had two primary objectives: (1) to identify predictors of hearing aid benefit among new users of hearing aids based on clinically applicable measures, and (2) to establish Minimal Clinically Important Differences (MCIDs) for several outcome measures when applied to the fitting of hearing devices.
Patients being fitted with hearing aids for the first time under an Australian Government-funded hearing services program were invited to complete three questionnaires: one prior to their hearing aid fitting, and follow-ups two weeks and eight weeks post-fitting. Measures taken prior to fitting included their readiness to wear hearing devices, the Wishes and Needs Tool, Part 1 of the Glasgow Hearing Aid Benefit Profile (GHABP), the Vanderbilt Fatigue Scale (VFS), the Social Isolation Measure (SIM), the Auditory Lifestyle and Demand Questionnaire, the Warwick-Edinburgh Mental Well-Being Scale (WEMWBS), the PROMIS Cognitive Function 8a scale, the Health Utilities Index Mark 3 (HUI-3), pure tone thresholds, and information about their medical history. Benefit was measured using Part 2 of the GHABP, the VFS, the SIM, the WEMWBS, and the HUI-3, and Clinical Global Impression. The effect of pre-fitting measures on benefit was determined using Multiple Indicator, Multiple Indicator Cause (MIMIC) models using Bayesian statistical methods. MCIDs were estimated using anchor-based methods.
This study is still in progress, and interim results will be presented.
The results of this study may be used by clinicians and policymakers to target the fitting of hearing devices to patients who are most likely to benefit from them.