Twenty consensus statements on unilateral cochlear implantation in adults with bilateral severe, profound or moderate sloping to profound sensorineural hearing loss have been agreed and endorsed by a so-called “Delphi panel” of 31 medical experts. The Delphi consensus process was guided by a Chair, Dr Craig Buchman, Head of Otolaryngology – Head & Neck Surgery, Washington University School of Medicine, USA.

Representatives from international cochlear implant user and professional advocacy organisations were also involved in the development of the consensus statements.

Seven key areas

The consensus statements on cochlear implants provide recommendations on seven key areas:

• Awareness of cochlear implants
• Best practice clinical pathway for diagnosis
• Best practice guidelines for surgery
• Clinical effectiveness of cochlear implants
• Factors associated with post implantation outcomes
• Relationship between hearing loss and depression, cognition and dementia
• Cost implications of cochlear implants.

What is a Delphi consensus process?

A Delphi consensus is an established technique that allows for consensus to be reached by a group of experts by the collection and aggregation of their informed judgements. In clinical research, the key aim of a Delphi consensus is to achieve a set of statements that reflect current clinical expert thinking in the field. The consensus statements can also make recommendations, for example, to improve the diagnosis or treatment of a specific condition or patient group.

Far too few are treated with cochlear implants

Many people affected by bilateral severe, profound, or moderate sloping to profound sensorineural hearing loss (SNHL) may not receive benefits from using hearing aids. For these people, cochlear implants are a treatment option.

But many adults with hearing loss are not receiving cochlear implants even though they would benefit from them. Conservative estimates suggest that no more than 1 in 20 adults who could benefit from a cochlear implant are treated with a cochlear implant.

Under-provision of cochlear implants leads to a substantial unnecessary burden to the individual with hearing loss, leading to a poorer quality of life and it may also have economic and social consequences. There are many reasons contributing to this under-provision, including low awareness of the benefits of cochlear implants among healthcare professionals and individuals with severe and profound hearing loss, as well as a lack of specific referral pathways.

The 20 statements

The 20 statements from the Delphi panel are:

Level of awareness of CIs
1.  Awareness of cochlear implants among primary and hearing healthcare providers is inadequate, leading to under-identification of eligible candidates. Clearer referral and candidacy pathways would help increase access to cochlear implants.

Best practice clinical pathway for diagnosis
2. Detection of hearing loss in adults is important; pure tone audiometry screening methods are considered the most effective. The addition of a questionnaire or interview to the screening can improve the detection of sensorineural hearing loss.

3. Preferred aided speech recognition tests for cochlear implant candidacy in adults include monosyllabic word tests and sentence tests, conducted in quiet and noise. Further standardisation of speech recognition tests is needed to facilitate comparison of outcomes across studies and countries.

4. Age alone should not be a limiting factor to cochlear implant candidacy, as positive speech recognition and quality of life outcomes are experienced by older adults as well as younger adults.

Best practice guidelines for surgery
5. Both curved (perimodiolar) and straight electrodes are clinically effective for cochlear implantation, with a low rate of complications.

6. When possible, hearing preservation surgery can be beneficial in individuals with substantial residual hearing.

Clinical effectiveness of CIs
7. Cochlear implants significantly improve speech recognition in both quiet and moderate noise in adults with bilateral severe, profound, or moderate sloping to profound sensorineural hearing loss; these gains in speech recognition are likely to remain stable over time.

8. Both word and sentence recognition tests should be used to evaluate speech recognition performance following cochlear implantation.

9. Cochlear implants significantly improve overall and hearing-specific quality of life in adults with bilateral severe, profound, or moderate sloping to profound sensorineural hearing loss.

10. Adults who are eligible for cochlear implants should receive the implant as soon as possible to maximise post-implantation speech recognition.

Factors associated with post-implantation outcomes
11. Long durations of unaided hearing loss do not rule out potential benefit of cochlear implants: individuals who receive an implant in an ear that was previously unaided for more than 15 years have been shown to experience improvements in speech recognition.

12. Adults who have undergone cochlear implantation should receive programming sessions, as needed, to optimize outcomes.

13. Where appropriate, individuals should use hearing aids with their cochlear implant in order to achieve bilateral benefits and the best possible speech recognition and quality of life outcomes.

14. Many factors impact cochlear implant outcomes; further research is needed to understand the magnitude of the effects.

The relationship between hearing loss and depression, cognition, and dementia
15. Adults with hearing loss can be substantially affected by social isolation, loneliness, and depression; evidence suggests that treatment with cochlear implants can lead to improvement in these aspects of well-being and mental health. Longitudinal studies are needed to obtain further knowledge in this area.

16. There is an association between age-related hearing loss and cognitive/memory impairment.

17. Further research is required to confirm the nature of cognitive impairment in individuals with hearing loss, and its potential reversibility with treatment.

18. The use of cochlear implants may improve cognition in older adults with bilateral severe to profound sensorineural hearing loss.

19. Hearing loss is not a symptom of dementia; however, treatment of hearing loss may reduce the risk of dementia.

Cost implications of CIs
20. Unilateral cochlear implantation in adults is cost-effective when compared with no implant or no intervention at all and is associated with increased employment and income.

Review and statement

“Unilateral Cochlear Implants for Severe, Profound, or Moderate Sloping to Profound Bilateral Sensorineural Hearing Loss, A Systematic Review and Consensus Statements” was published in the journal JAMA Otolaryngology – Head & Neck Surgery.

Sources: Delphi Consensus Cochlear Implants Leave Piece and JAMA Otolaryngology–Head & Neck Surgery, International Consensus Paper, Standard of care and Delphi Consensus Cochlear Implants Leave Piece