Psychometric properties of a revised Danish translation of the international outcome inventory for hearing aids (IOI-HA)

Focusing on positive listening experiences improves hearing aid outcomes in first-time hearing aid users: a randomized controlled trial

OBJECTIVE

The objective of this study was to investigate whether positive focus (PF), an intervention that asks hearing aid users to focus on positive listening experiences, improves hearing aid outcomes for first-time hearing aid users.

DESIGN

The participants were randomised into a control or PF group. They were fitted with hearing aids and followed for six months after fitting. The PF group was asked to report positive listening experiences in their daily life via an app. Participants in both groups were periodically prompted by the app to answer questionnaires about hearing aid satisfaction and benefit. Two follow-up visits at approximately one and six months were performed.

STUDY SAMPLE

20 adult first-time hearing aid users in the control and 18 in the PF group.

RESULTS

Hearing aid satisfaction and benefit scores were significantly better in the PF group, already at two weeks and throughout the six months. In the PF group, the hearing aid outcomes were positively correlated with the number of submitted positive reports.

CONCLUSIONS

These results point to the importance of asking first-time hearing aid users to focus on positive listening experiences and to reflect upon them. This can lead to improved short- and long-term hearing aid outcomes.

Focusing on positive listening experiences improves hearing aid outcomes in experienced hearing aid users

OBJECTIVE

The purpose of this study was to investigate whether focusing on positive listening experiences improves hearing aid outcomes in experienced hearing aid users.

DESIGN

The participants were randomised into a control or positive focus (PF) group. At the first laboratory visit, the Client-Oriented Scale of Improvement (COSI) questionnaire was administered followed by hearing aid fitting. The participants wore the hearing aids for three weeks. The PF group was asked to report their positive listening experiences via an app. During the third week, all the participants answered questionnaires related to hearing aid benefit and satisfaction. This was followed by the second laboratory visit where the COSI follow-up questionnaire was administered.

STUDY SAMPLE

Ten participants were included in the control and eleven in the PF group.

RESULTS

Hearing aid outcome ratings were significantly better in the PF group in comparison to the control group. Further, COSI degree of change and the number of positive reports were positively correlated.

CONCLUSIONS

These results point to the importance of asking hearing aid users to focus on positive listening experiences and talk about them. The potential outcome is increased hearing aid benefit and satisfaction which could lead to more consistent use of the devices.

Piezoelectric Bone Conduction Hearing Implant: A Case Series of Audiological, Surgical and Patient-Reported Outcomes

Objective: To examine the surgical, audiological and patient-reported outcomes of the Osia 2 implant. Methods: Data from 14 consecutive subjects undergoing implantation between April 2022 and November 2023 were reviewed. Ten subjects had conductive hearing loss, three had mixed hearing loss and one had single-sided deafness (SSD). Warble tone thresholds, Pure Tone Average (PTA4) and Speech Discrimination Score (SDS) in quiet and in noise were determined unaided and aided. The subjective outcome was determined from two standardized questionnaires: (1) International Outcome Inventory for Hearing Aids (IOI-HA) and (2) Speech, Spatial and Qualities of Hearing Scale 12 (SSQ12b). Results: Unexpected postoperative pain was found in four cases. The warble tone thresholds exhibited a consistent reduction across all frequencies, contributing to a mean decrease of 27 dB in the aided PTA4. SDS demonstrated notable improvements, with a 57.3% increase at 50 dB and a 55.6% increase at 65 dB. In noise, SDS exhibited a 43.9% improvement. The mean IOI-HA Score was 3.8, and the mean overall score for SSQ12b was 6.6, with consistent findings across the subgroups. Conclusions: The Osia device emerges as a promising recommendation for individuals with conductive or mixed hearing loss, possibly also for those with SSD. Its safety and efficacy profile aligns with the broader category of active transcutaneous devices, demonstrating a reduced risk of wound infection compared to percutaneous alternatives. Both audiological assessments and subjective evaluations revealed positive outcomes.

Effects of remote ear-nose-and-throat specialist assessment screening on self-reported hearing aid benefit and satisfaction

OBJECTIVE

To explore the impact of remote versus in-person ear-nose-and-throat (ENT) specialist screening before hearing treatment on self-reported hearing aid (HA) benefit and satisfaction among adult first-time HA users.

DESIGN

Participants were randomised to either remote or in-person ENT assessment before treatment initiation. Hearing ability, hearing quality, and treatment satisfaction were assessed pre- and post-HA treatment using the SSQ12, IOI-HA, and selected items from the 2021 Danish national Patient-Reported Experience Measures. Average daily HA usage was also recorded.

STUDY SAMPLE

751 adult potential first-time HA users with self-reported hearing impairment were included; 501 participants were remotely assessed in private or public audiological clinics, and 250 control group participants were assessed in-person by private ENT specialists. Of the 658 participants who completed the entire trial, 454 received HAs.

RESULTS

No significant post-treatment HA benefit differences were found between groups. Remotely assessed HA recipients in private clinics expressed slightly higher staff and waiting time satisfaction. Participants with normal hearing and mild/moderate hearing loss reported higher pre-treatment hearing ability and quality. No significant difference in average daily HA usage was observed between groups.

CONCLUSIONS

Findings suggest that remote screening does not compromise patient-reported HA benefit and satisfaction when compared to in-person screening.

Difference in SII provided by initial fit and NAL-NL2 and its relation to self-reported hearing aid outcomes

OBJECTIVE

The speech intelligibility index (SII) is used to quantify the audibility of the speech. This study examined the relationship between self-reported hearing aid (HA) outcomes and the difference in aided SII (SIIA) calculated from the initial fit (IF) gain and that prescribed as per the second generation of National Acoustic Laboratory Non-Linear (NAL-NL2).

DESIGN

A prospective observational study.

STUDY SAMPLE

The study included 718 first-time and 253 experienced HA users. All users had a valid real-ear measurement (REM) at three input levels (55, 65 and 80 dB SPL).

RESULTS

The gain provided by IF was lower than NAL-NL2 at 55 and 65 dB SPL. IF gain exhibited reduced compression than NAL-NL2 as input levels increased from 55 to 80 dB SPL. On average, the SIIA provided by IF was significantly lower than that for NAL-NL2 at all input levels. The difference in SIIA between IF and NAL-NL2 at 80 dB SPL input level with 0 dB signal-to-noise ratio (SNR) turned out to be a predictor for self-reported outcome for first-time HA users.

CONCLUSION

The study suggests that an SIIA close to that provided by NAL-NL2 at high input levels would be preferred to obtain a better self-reported outcome. .

Remote hearing aid renewal using pre-existing audiograms during the covid-19 pandemic

OBJECTIVE

During the ongoing Covid-19 pandemic, many patients cancelled their scheduled hearing aid renewal. We offered to send them new hearing aids programmed according to the audiometric data on file. In this study we compared remote hearing aid renewal to a conventional renewal with a recent audiogram based on scores from the International Outcome Inventory for Hearing Aids (IOI-HA) questionnaire. We also examined the need for a physical visit for hearing aid adjustment in the remote group and analysed the accuracy of the pre-existing audiogram correction method using data from the control group.

DESIGN

Retrospective chart review.

STUDY SAMPLE

51 patients who underwent remote hearing aid renewal and 22 control patients who received office-based hearing aid renewal.

RESULTS

IOI-HA scores were lower in the remote fitted group, but comparison with data from a Swedish nationwide database had no clinically significant differences. A follow-up physical appointment was required in only 20% of the remote group. The intraclass correlation coefficient (ICC) between the pure tone averages of the corrected former audiogram and measured audiogram was high.

CONCLUSIONS

Remote hearing aid renewal using existing audiometric data is feasible, and most physical visits can be avoided.

Impact of hearing aid technology level at first-fit on self-reported outcomes in patients with presbycusis: a randomized controlled trial

To provide clinical guidance in hearing aid prescription for older adults with presbycusis, we investigated differences in self-reported hearing abilities and hearing aid effectiveness for premium or basic hearing aid users. Secondly, as an explorative analysis, we investigated if differences in gain prescription verified with real-ear measurements explain differences in self-reported outcomes. The study was designed as a randomized controlled trial in which the patients were blinded towards the purpose of the study. In total, 190 first-time hearing aid users (>60 years of age) with symmetric bilateral presbycusis were fitted with either a premium or basic hearing aid. The randomization was stratified on age, sex, and word recognition score. Two outcome questionnaires were distributed: the International Outcome Inventory for Hearing Aids (IOI-HA) and the short form of the Speech, Spatial, and Qualities of Hearing Scale (SSQ-12). In addition, insertion gains were calculated from real-ear measurements at first-fit for all fitted hearing aids. Premium hearing aid users reported 0.7 (95%CI: 0.2; 1.1) scale points higher total SSQ-12 score per item and 0.8 (95%CI: 0.2; 1.4) scale points higher speech score per item, as well as 0.6 (95%CI: 0.2; 1.1) scale points higher qualities score compared to basic-feature hearing aid users. No significant differences in reported hearing aid effectiveness were found using the IOI-HA. Differences in the prescribed gain at 1 and 2 kHz were observed between premium and basic hearing aids within each company. Premium-feature devices yielded slightly better self-reported hearing abilities than basic-feature devices, but a statistically significant difference was only found in three out of seven outcome variables, and the effect was small. The generalizability of the study is limited to community-dwelling older adults with presbycusis. Thus, further research is needed for understanding the potential effects of hearing aid technology for other populations. Hearing care providers should continue to insist on research to support the choice of more costly premium technologies when prescribing hearing aids for older adults with presbycusis. Clinical Trial Registration: https://register.clinicaltrials.gov/, identifier NCT04539847.

Self-Reported Hearing-Aid Use Patterns in an Adult Danish Population

The retrospective reporting of users’ hearing aid (HA) usage can provide insight into individualized HA usage patterns. Understanding these HA usage patterns can help to provide a tailored solution to meet the usage needs of HA users. This study aims to understand the HA usage pattern in daily-life situations from self-reported data and to examine its relationship to self-reported outcomes. A total of 1537 participants who responded to questions related to situations where they always took off or put on the HAs were included in the study. A latent class analysis was performed to stratify the HA users according to their HA usage pattern. The results showed distinct usage patterns in the latent classes derived for both scenarios. The demographics, socio-economic indicators, hearing loss, and user-related factors were found to impact HA usage. The results showed that the HA users who reported using the HAs all the time (regular users) had better self-reported HA outcomes than situational users, situational non-users, and non-users. The study explained the underlying distinct HA usage pattern from self-reported questionnaires using latent class analysis. The results emphasized the importance of regular use of HAs for a better self-reported HA outcome.

Comparing Hearing Aid Outcomes in Adults Using Over-the-Counter and Hearing Care Professional Service Delivery Models

PURPOSE

More affordable hearing aids are now available due to over-the-counter (OTC) hearing aid regulations. Although laboratory studies have validated many OTC hearing technologies, there are limited real-world benefit studies. This study compared hearing aid outcomes reported by clients from OTC and conventional hearing care professional (HCP) service delivery models.

METHOD

An ecological, cross-sectional survey design was employed. An online survey was sent to the Hearing Tracker user and OTC Lexie hearing aid user databases. Moreover, 656 hearing aid users completed the survey-406 through conventional HCP services (M _age = 66.7 ± 13.0 years) and 250 through the OTC model (M _age = 63.7 ± 12.2 years). Self-reported hearing aid benefit and satisfaction were measured with the International Outcome Inventory for Hearing Aids outcome tool.

RESULTS

No significant difference for overall hearing aid outcomes between HCP and OTC users was evident using regression analyses, controlling for age, gender, duration of hearing loss, duration before hearing aid purchase, self-reported hearing difficulty, and unilateral versus bilateral fitting. For the "daily use" domain, HCP clients reported significantly longer hours of daily use. For the "residual activity limitations" domain, OTC hearing aid users reported significantly less difficulty hearing in situations where they most wanted to hear better.

CONCLUSIONS

OTC hearing aid outcomes could complement and provide similar satisfaction and benefit to HCP models for adults. Service delivery aspects such as self-fitting, acclimatization programs, remote support, behavioral incentivization, and payment options should be investigated for their potential role in OTC hearing aid outcomes.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.22134788.

Comparison of hearing aid fitting effectiveness with audiograms from either user-operated or traditional audiometry in a clinical setting: a study protocol for a blinded non-inferiority randomised controlled trial

INTRODUCTION

There is a worldwide need to enhance the capacity of audiometry testing. The objective of this study is to compare the User-operated Audiometry (UAud) system with traditional audiometry in a clinical setting, by investigating if hearing aid effectiveness based on UAud is non-inferior to hearing aid effectiveness based on traditional audiometry, and whether thresholds obtained with the user-operated version of the Audible Contrast Threshold (ACT) test correlates to traditional measures of speech intelligibility.

METHODS AND ANALYSIS

The design will be a blinded non-inferiority randomised controlled trial. 250 adults referred for hearing aid treatment will be enrolled in the study. Study participants will be tested using both traditional audiometry as well as the UAud system and they will answer the questionnaire Speech, Spatial and Qualities of Hearing Scale (SSQ12) at baseline. Participants will be randomly divided to receive hearing aids fitted based on either UAud or traditional audiometry. Three months after participants have started using their hearing aids, they will undergo a hearing in noise test with hearing aids to measure their speech-in-noise performance and answer the following questionnaires: SSQ12, the Abbreviated Profile of Hearing Aid Benefit and the International Outcome Inventory for Hearing Aids. The primary outcome is a comparison of the change in SSQ12 scores from baseline to follow-up between the two groups. Participants will undergo the user-operated ACT test of spectro-temporal modulation sensitivity as part of the UAud system. The ACT results will be compared with measures of speech intelligibility from the traditional audiometry session and follow-up measurements.

ETHICS AND DISSEMINATION

The project was evaluated by the Research Ethics Committee of Southern Denmark and judged not to need approval. The findings will be submitted to an international peer-reviewed journal and presented at national and international conferences.

TRIAL REGISTRATION NUMBER

NCT05043207.

Predicting Aided Outcome With Aided Word Recognition Scores Measured With Linear Amplification at Above-conversational Levels

OBJECTIVES

Many hearing aid (HA) users receive limited benefit from amplification, especially when trying to understand speech in noise, and they often report hearing-related residual activity limitations. Current HA fitting strategies are typically based on pure-tone hearing thresholds only, even though suprathreshold factors have been linked to aided outcomes. Furthermore, clinical measures of speech perception such as word recognition scores (WRSs) are performed without frequency-specific amplification, likely resulting in suboptimal speech audibility and thus inaccurate estimates of suprathreshold hearing abilities. Corresponding measures with frequency-specific amplification ("aided") would likely improve such estimates and enable more accurate aided outcome prediction. Here, we investigated potential links between either unaided WRSs or aided WRSs measured at several above-conversational levels and two established HA outcome measures: The Hearing-In-Noise Test (HINT) and the International Outcome Inventory for Hearing Aids (IOI-HA).

DESIGN

Thirty-seven older individuals with bilateral hearing impairments participated. Two conditions were tested: unaided and aided, with all stimuli presented over headphones. In the unaided condition, the most comfortable level (MCL) for the presented speech stimuli, WRS at MCL+10 dB as well as uncomfortable levels (UCLs) for narrowband noise stimuli were measured. In the aided condition, all stimuli were individually amplified according to the "National Acoustic Laboratories-Revised, Profound" fitting rule. Aided WRSs were then measured using an Interacoustics Affinity system at three above-conversational levels, allowing for the maximum aided WRS as well as the presence of "rollover" in the performance-intensity function to be estimated. Multivariate data analyses were performed to examine the relations between the HINT (measured using a simulated HA with the NAL-RP amplification) or IOI-HA scores (for the participants' own HAs) and various potential predictors (age, pure-tone average hearing loss, unaided WRS, aided WRS, rollover presence [ROp], and UCL).

RESULTS

Aided WRSs predicted the HINT scores better than any other predictor and were also the only significant predictor of the IOI-HA scores. In addition, UCL and ROp in the aided WRSs were significant predictors of the HINT scores and competed for variance in the statistical models. Neither age nor pure-tone average hearing loss could predict the two aided outcomes.

CONCLUSIONS

Aided WRSs can predict HA outcome more effectively than unaided WRSs, age or pure-tone audiometry and could be relatively easily implemented in clinical settings. More research is necessary to better understand the relations between ROp, UCL and speech recognition at above-conversational levels.

Can real-ear insertion gain deviations from generic fitting prescriptions predict self-reported outcomes?

OBJECTIVE

The aim of this study was to determine whether the differences in insertion gains from the first fit to generic prescriptions of hearing aids can predict the self-reported hearing aid (HA) outcomes for first-time and experienced HA users.

DESIGN

This was a prospective observational study.

STUDY SAMPLE

The study included 885 first-time and 330 experienced HA users with a valid real-ear measurement on both ears and answers to the abbreviated version of the Speech, Spatial, and Quality of Hearing (SSQ12) and the International Outcome Inventory for Hearing Aids (IOI-HA) questionnaires.

RESULTS

K-means clustering of gain differences between individual real-ear insertion gain to three generic gain prescriptions (NAL-NL2, NAL-RP, and one-third gain rules) was performed. The gain difference at higher frequencies generally differentiated the clusters. The experienced users in the cluster with fittings closest to NAL-NL2 and NAL-RP prescription were found to exhibit a higher IOI-HA Factor 1 score (representing the overall benefit of the hearing aid use). The gain differences to generic prescription did not affect other self-reported outcomes for first-time and experienced HA users.

CONCLUSION

The experienced HA users with minimal gain deviations from generic prescriptions reported better self-perceived benefits than users with larger deviations. However, this was not apparent in first-time users.

Psychometric properties for the Norwegian translations of two revised APHAB-subscales and an adapted IOI-HA (IOI-CI) in patients with cochlear implants

OBJECTIVE

The objective was to examine the psychometric properties of two questionnaires in Norwegian for the self-assessment of satisfaction following cochlear implantation.

DESIGN

The International Outcome Inventory for Hearing Aids adapted for cochlear implants (IOI-CI) and two revised subscales from the Norwegian translation of the Abbreviated Profile of Hearing Aid Benefit (APHAB) were applied. Internal consistency was tested using Cronbach's α. Testing of psychometric properties included the calculation of inter-item correlations and corrected item-total correlations. Spearman's rho was used to investigate associations. Exploratory principal component analyses with Kaiser normalisation were performed.

STUDY SAMPLE

One hundred and twenty-one patients (51 males) with cochlear implants (27-88 years, M = 59).

RESULTS

For IOI-CI, Cronbach's α was 0.79. Corrected item-total correlations ranged from 0.29 to 0.69. The factor analysis revealed two components. For APHAB, Cronbach's α was 0.91. Two components were revealed by the factor analysis. Corrected item-total correlations for the two subscales "communication in quiet situations" and "communication in adverse situations" were 0.47-0.81 and 0.58-0.80, respectively. The convergent validity of the questionnaires was adequate as reflected by a Spearman's coefficient of 0.67.

CONCLUSION

Both questionnaires show good psychometric properties.

Prediction of successful hearing aid treatment in first-time and experienced hearing aid users: Using the International Outcome Inventory for Hearing Aids

OBJECTIVE

Primarily to understand whether clinically relevant factors affect the International Outcome Inventory (IOI-HA) scores and to examine if IOI-HA scores improve when renewing the hearing aids (HA) for experienced users. Secondly, to estimate the overall HA effectiveness using the IOI-HA.

DESIGN

A prospective observational study.

STUDY SAMPLE

In total, 1961 patients with hearing loss were included. All patients underwent a hearing examination, were fitted with HAs, and answered the IOI-HA. Factor analysis of IOI-HA separated the items into a Factor 1 (use of HA, perceived benefits, satisfaction, and quality of life) and Factor 2 (residual activity limitation, residual participation restriction and impact on others) score.

RESULTS

Degree of hearing loss, word recognition score, motivation, HA usage time, tinnitus, asymmetry, and sex were significantly associated with total IOI-HA, Factor 1, or Factor 2 scores. The seven IOI-HA items increased on average by 0.4 (p < 0.001) when renewing HAs. The total median IOI-HA score at follow-up was 29 (7) for experienced (n = 460) and first-time users (n = 1189), respectively.

CONCLUSIONS

Degree of hearing loss, word recognition score, motivation, tinnitus, asymmetry, and sex may be used to identify patients who require special attention to become successful HA users.

Psychometric properties of the Kannada version of the International Outcome Inventory for Hearing Aids (IOI-HA)

OBJECTIVE

This study aimed to validate the translated Kannada version of the International Outcome Inventory for Hearing Aids (IOI-HA) questionnaire for hearing aid users.

DESIGN

The original (English) and the translated versions of the IOI-HA questionnaire along with the Self-Assessment of Communication (SAC) were self-administered by hearing aid users. To examine test-retest reliability, 50% of the study participants completed the Kannada IOI-HA for a second time approximately 15 days later. The data analyses examined various psychometric properties using a predetermined quality criterion.

STUDY SAMPLE

105 Kannada-English bilingual adults using hearing aids.

RESULTS

Factor analysis indicated a two-factor structure that explained a 61.8% variance in the IOI-HA. A Cronbach's alpha coefficient of 0.7 indicated acceptable internal consistency. Good test-retest reliability (Interclass Correlation Coefficient > 0.9) was obtained for both conditions (i.e. between the original English and translated Kannada versions and also between two different administrations of the Kannada IOI-HA questionnaire). Divergent validity test results were acceptable, and no ceiling or floor effects were noted. Convergent validity testing of the SAC, however, was poor with small correlation, although the direction of correlation (i.e. negative) was as expected.

CONCLUSION

Results suggest acceptable psychometric properties of the Kannada version of the IOI-HA questionnaire.

Analysis of data from the International Outcome Inventory for Hearing Aids (IOI-HA) using Bayesian Item Response Theory

OBJECTIVE

IOI-HA response data are conventionally analysed assuming that the ordinal responses have interval-scale properties. This study critically considers this assumption and compares the conventional approach with a method using Item Response Theory (IRT).

DESIGN

A Bayesian IRT analysis model was implemented and applied to several IOI-HA data sets.

STUDY SAMPLE

Anonymised IOI-HA responses from 13273 adult users of one or two hearing aids in 11 data sets using the Australian English, Dutch, German and Swedish versions of the IOI-HA.

RESULTS

The raw ordinal responses to IOI-HA items do not represent values on interval scales. Using the conventional rating sum as an overall score introduces a scale error corresponding to about 10 - 15% of the true standard deviation in the population. Some interesting and statistically credible differences were demonstrated among the included data sets.

CONCLUSIONS

It is questionable to apply conventional statistical measures like mean, variance, t-tests, etc., on the raw IOI-HA ratings. It is recommended to apply only nonparametric statistical test methods for comparisons of IOI-HA results between groups. The scale error can sometimes cause incorrect conclusions when individual results are compared. The IRT approach is recommended for analysis of individual results.

Factors associated with the efficiency of hearing aids for patients with age-related hearing loss

Objective

The aim of this study was to investigate the satisfaction of age-related hearing loss (ARHL) or presbycusis patients with individual, accurate, and precise fitting progress, which is a priority for bilateral hearing aids, and to explore the related influencing factors and their role in predicting the efficiency of hearing aids.

Methods

A total of 73 cases of presbycusis patients aged 60–95 years old underwent pure tone audiometry and speech recognition ability examination to obtain the pure tone audiometry of the better ear (BPTA) and maximum speech recognition rate of the better ear (BSRR) in quiet environment before hearing aid fitting. Audiologists evaluated the efficiency and satisfaction of participants according to the International Outcome Inventory for Hearing Aids (IOI-HA) questionnaire scores by face-to-face or telephone investigations after using the hearing aids for at least 3 months. The data were analyzed related to possible influencing factors.

Results

Total satisfaction percentage according to IOI-HA scores was 86.3%. There was no significant correlation between age, first fitting age, unilateral or bilateral hearing aids, BPTA, and IOI-HA total score. BSRR was strongly correlated to total IOI-HA scores (r=0.768). According to the multiple linear regression analysis, BPTA and BSRR both had a statistically significant effect on the total IOI-HA scores after hearing aid intervention.

Conclusion

ARHL patients with accurate hearing aid fitting will have high satisfaction and bilateral hearing aids are better than unilateral ones. Age and first fitting age are not meaningful to satisfaction with hearing aids. A higher maximum speech recognition rate before hearing aids fitting could predict better efficiency and satisfaction with hearing aids. Therefore, completing speech recognition ability examination before fitting would make a great contribution to the efficiency of hearing aids, and help ARHL patients have realistic expectations.

International Outcome Inventory for Hearing Aids: Data From a Large Swedish Quality Register Database

PURPOSE

The purpose of this study was to analyze a database of completed International Outcome Inventory for Hearing Aids (IOI-HA) questionnaires obtained from over 100,000 clients fitted with new hearing aids in Sweden during the period of 2012-2016. Mean IOI-HA total scores were correlated with degree of hearing loss, unilateral versus bilateral fitting, first-time versus return clients, gender, and variation among dispensing clinics. The correlations with expectations, service quality, and technical functioning of the hearing aids were also analyzed.

METHOD

Questionnaires containing the 7 IOI-HA items as well as questions concerning some additional issues were mailed to clients 3-6 months after fitting of new hearing aids. The questionnaires were returned to and analyzed by an independent research institute.

RESULTS

More than 100 dispensing clinics nationwide take part in this project. A response rate of 52.6% resulted in 106,631 data sets after excluding incomplete questionnaires. Forty-six percent of the responders were women, and 54% were men. The largest difference in mean score (0.66) was found for the IOI-HA item "use" between return clients and first-time users. Women reported significantly higher (better) scores for the item "impact on others" compared with men. The bilaterally fitted subgroup reported significantly higher scores for all 7 items compared with the unilaterally fitted subgroup. Experienced users produced higher scores on benefit and satisfaction items, whereas first-time users gave higher scores for residual problems. No correlation was found between mean IOI-HA total score and average hearing threshold level (pure-tone average [PTA]). Mean IOI-HA total scores were found to correlate significantly with perceived service quality of the dispensing center and with the technical functionality of the hearing aids.

CONCLUSIONS

When comparing mean IOI-HA total scores from different studies or between groups, differences with regard to hearing aid experience, gender, and unilateral versus bilateral fitting have to be considered. No correlation was found between mean IOI-HA total score and degree of hearing loss in terms of PTA. Thus, PTA is not a reliable predictor of benefit and satisfaction of hearing aid provision as represented by the IOI-HA items. Identification of a specific lower fence in PTA for hearing aid candidacy is therefore to be avoided. Large differences were found in mean IOI-HA total scores related to different dispensing centers.