Adult-onset Hearing Loss Research Articles

The WHO-DAS II: Measuring Outcomes of Hearing Aid Intervention for Adults

The World Health Organization's Disability Assessment Scale II (WHO-DAS II) is a generic health-status instrument that provides six domain scores and a total, aggregate score. Two of the domain scores, communication and participation, and the total score, have good validity, internal-consistency reliability, and test-retest stability in individuals with adult-onset hearing loss. As such, these two domain scores and the total WHO-DAS II score may be useful as generic outcome measures to assess the effectiveness of hearing aid intervention for this population. Before the use of the WHO-DAS II in hearing aid clinical trials, however, the responsiveness of the instrument and the short- and long-term outcomes to hearing aid intervention had to be determined. Responsiveness and outcomes were assessed in 380 veterans (approximately half received hearing aids and half served as controls) by examining group differences, effect-size estimates, and individual differences as a function of hearing aid intervention. For comparison, data also were obtained on two disease-specific measures, the APHAB and the HHIE. The WHO-DAS II communication domain and total scores were sufficiently responsive to hearing aid intervention for use in future studies in which group differences are to be detected. The WHO-DAS II participation domain was not sufficiently responsive to hearing aid intervention. The APHAB and HHIE, both disease-specific measures, were more sensitive to hearing aid intervention than the generic measure. The short- and long-term outcomes of hearing aid intervention were also examined in the present study. Group outcomes for hearing aid intervention can be expected to be stable for at least 6 months when measured by WHO-DAS II total score and for at least 12 months when measured by the WHO-DAS II communication domain scores. Effect-size estimates and examination of the number of individuals exhibiting change scores exceeding 90% critical differences for true changes in scores indicate that for clinical applications, disease-specific instruments are more useful than the WHO-DAS II. The findings of this study support the use of the WHO-DAS II as a generic measure in hearing aid trials research so as to allow for comparisons of health-status outcomes across different diseases or disorders.

Short- and Long-Term Outcomes of Adult Audiological Rehabilitation

To examine short- and long-term subjective benefits of providing a counseling-oriented audiological rehabilitation (AR) program as an adjunct to hearing aid intervention for individuals with adult-onset hearing loss. One hundred six veterans (68 men and 38 women), fit binaurally with digitally programmable analog hearing aids, participated. The Communication Profile for the Hearing Impaired (CPHI; ) was administered to all participants before hearing aid fitting. Half the patients were randomly assigned to receive hearing aids alone (i.e., control); the other patients were assigned to participate in a 4-wk group AR program in conjunction with receiving hearing aids (i.e., HA + AR). At the end of the AR program, the CPHI was again administered to all participants to assess short-term benefit and at 6 mo and 1 yr after hearing aid fitting to assess long-term benefit. A separate repeated-measures version of the general linear model was used to examine short- and long-term benefits for the CPHI factor scores (communication importance, communication performance, adjustment, interaction, and reaction) and for individual importance ratings and scale scores. Hearing aid use improved both short- and long-term self-perception of communication performance, with no additional benefits from participation in the AR program. Consistent with the goals of a counseling-oriented AR program, differential short-term treatment effects were found for communication strategy usage, which led to differential short-term benefits for the interaction and reaction factors. Although failing to reach strict criteria for statistical significance, there was an observable difference in short-term outcomes between the two groups for the adjustment factor, with greater improvements occurring for the HA + AR group. Over the course of the year, benefits measured for the HA + AR group remained stable, whereas scores for the control group continued to increase, resulting in no differences in factor scores between groups at 1 yr after intervention. The finding of a short-term differential treatment benefit for AR in terms of interaction and reaction, and possibly for adjustment, was important, as better outcomes in these areas may be important in the decision to keep hearing aids. If this is the case, then the data support the inclusion of a counseling-oriented AR program. Differential treatment effects in interaction and reaction appeared to result from communication strategy use, indicating that the AR program is meeting many of its goals in this area. The lack of long-term differential effects appeared as the result of continued changes in adjustment, interaction, and reaction with continued hearing aid experience.

Mitochondrial DNA mutations in patients with postlingual, nonsyndromic hearing impairment.

Mitochondrial mutations have previously been reported anecdotally in families with maternally inherited, nonsyndromic hearing impairment. To ascertain the contribution of mitochondrial mutations to postlingual but early-onset, nonsyndromic hearing impairment, we screened patients collected from within two different populations (southern Italy and UK) for previously reported mtDNA mutations associated with hearing disorders. Primer extension (SNP analysis) was used to screen for specific mutations, revealing cases of heteroplasmy and its extent. The most frequently implicated tRNA genes, Leu(UUR) and Ser(UCN), were also sequenced in all Italian patients. All tRNA genes were sequenced in those UK patients showing the clearest likelihood of maternal inheritance. Causative mtDNA mutations were found in approximately 5% of patients in both populations, representing almost 10% of cases that were clearly familial. Age of onset, where known, was generally before adulthood, and hearing loss was typically progressive. Haplogroup analysis revealed a possible excess of haplogroup cluster HV in the patients, compared with population controls, but of borderline statistical significance. In contrast, we did not find any of the previously reported mtDNA mutations, nor a significant deviation from haplogroup cluster frequencies typical of the control population, in patients with late adult-onset hearing loss (age-related hearing impairment) from the UK or Finland.

Counselling clients with acquired hearing impairment: towards improved understanding and communication

This article seeks to bring to the attention of counsellors and counselling psychologists specific knowledge and awareness in working with clients with adult onset hearing loss. The need for improved awareness of the needs of these clients is argued, the experience of hearing loss explored, and psychological issues at the core of the disability discussed. Practical matters about communication that need consideration in the counselling setting are examined. It is presented from the vantage point of an experienced counselling psychologist who is herself hearing impaired.

The relationship between audiometric and self-report measures of hearing handicap.

In 430 individuals with adult onset hearing loss, relationships were explored between definitions of handicap based on a number of arithmetic formulas applied to audiometric data and definitions of handicap based on two self-report questionnaires (the Denver Scale of Communication Function and the Social Hearing Handicap Index). Resulting linear correlations were very low with the highest relationship--between better ear pure-tone average and perceived handicap--being only 0.38. Of the standard hearing handicap formulas, the 1947 American Medical Association calculation and the 1980 Ohio State formula showed the highest correlations with perceived handicap (0.33 and 0.28, respectively). The results highlight the difference between audiometrically calculated and self-reported hearing handicap.