International Consensus Process and Publication

This is the first time that experts from different countries and several continents have come together in order to create a document that reflects the status of cochlear implantation for adult recipients.

Professor Thomas Lenarz, Steering committee member of the Consensus Delphi Process and Director HNO-Klinik, Medizinische Hochschule Hannover, Germany.

Overcoming the barriers – consensus statements

To address lack of awareness and to improve literacy surrounding CI use in adults, an international group of clinical experts in the fields of otology, audiology, and hearing science, all with extensive clinical and scientific experience of cochlear implantation, were brought together to form a Delphi panel. The aim of the group was to use a modified Delphi method to develop a series of consensus statements regarding the use of unilateral CIs for treating bilateral severe, profound, or moderate sloping to profound SNHL.

Professor Gerard O’ Donoghue, steering committee member of the Consensus Delphi Process and Professor of Otology and Neurotology at the University of Nottingham, explains more below.

The ultimate goal of the consensus statements is to raise awareness of cochlear implants, and improve clinical practice to provide the best possible hearing outcomes and quality of life in adults with SNHL who are eligible for a cochlear implant. (Professor Gerard O’Donoghue)

Hear more from Professor Craig Buchman, Chair of the Consensus Delphi Process Steering Committee and Head of Otolaryngology – Neck Surgery, Washington University School of Medicine, U.S., presenting at ACIA 2019, and Associate Professor Holly Teagle, University of Auckland, New Zealand, at Pindrop.

Access a digital copy of the International Consensus Paper

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. The process seeks to achieve consensus, using rounds of questionnaires to seek anonymous responses that are then aggregated and voted on. 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 may also go further and make recommendations, for example, to improve the diagnosis or treatment of a specific condition or patient group.

Why is a Delphi consensus needed?

Hearing loss is one of the leading causes of disability worldwide.1 Although hearing aids are effective for many individuals with hearing loss, those affected by bilateral severe, profound, or moderate sloping to profound sensorineural hearing loss (SNHL) may not receive benefits, or adequate benefit, from hearing aids. For these individuals, cochlear implants are a treatment option. Many adults with hearing loss are not receiving cochlear implants even though they would benefit from them2.

Conservative industry estimates suggest that no more than 1 in 20 adults who could benefit from a cochlear implant have one.3,4 Under-provision leads to a substantial unnecessary burden to the individual with hearing loss, leading to a poorer quality of life;3 it may also have economic and social consequences.5-7 There are many reasons contributing to this under-provision, including low awareness of the benefits of cochlear implants among healthcare professionals and individuals with SNHL, as well as a lack of specific referral pathways.

Click to hear Delphi member Professor Piotr H. Skarżyński, MD, Ph.D, MSc. discuss the process and methodology behind the consensus process.

How was it done?

Systematic literature review

A systematic literature review was conducted to identify studies relevant to at least one of six key areas:

i) level of awareness of cochlear implants;
ii) best practice clinical pathway from diagnosis to surgery;
iii) best practice guidelines for surgery;
iv) best practice guidelines for rehabilitation;
v) factors that impact cochlear implant performance and outcomes; and
vi) cost implications of cochlear implants.

Identified studies were manually checked against pre-specified eligibility criteria, and data relevant to the six areas of interest were extracted from the included studies.

Studies were excluded for the following reasons: sample size less than 20, case studies or narrative reviews, studies published before 2005, paediatric studies, bilateral cochlear implants or electro-acoustic stimulation or hybrid hearing studies. Statements for consensus development were drafted based on the data in the included studies.

Delphi voting process

All members of the steering committee and the Delphi panel, except the Chair, were able to vote in the consensus process. Voting on the draft consensus statements took place over three rounds: two rounds by questionnaire remotely, and one at a face-to-face meeting.

At each voting round, the statements were voted on anonymously using an online questionnaire. Consensus was defined a priori as agreement by at least 75% of respondents.

What Were The Outcomes?

The consensus statements 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 postimplantation outcomes
  • Relationship between hearing loss and depression, cognition and dementia
  • Cost implications of cochlear implants

Twenty consensus statements have been agreed and endorsed by the Delphi panel.

What are the implications for clinical practice?

The publication of the consensus statements will be the first step in working towards the development of best practice clinical guidelines for unilateral cochlear implant use in adults with bilateral severe, profound, or moderate sloping to profound SNHL. The Delphi panel and a Consumer and Professional Advocacy Committee (CAPAC) will work to promote the endorsement of the consensus statements regionally, nationally and internationally to improve access to and best clinical practice for the use of cochlear implants for those with hearing loss.

Next steps in the process

The scope of this consensus study was to develop consensus statements specifically related to the use of unilateral CI for the treatment of bilateral severe, profound, or moderate sloping to profound SNHL in adults. However, further research to develop consensus statements on the use of bilateral CI in adults, unilateral and bilateral CI in children, combined electric-acoustic stimulation in children and adults and unilateral implantation for single-sided deafness and asymmetrical hearing loss in adults and children will also be important for optimising hearing and QoL outcomes for patients.

Who was involved in the Delphi consensus process?

The Delphi consensus process was guided by a non-voting Chair, Dr Craig Buchman, Head of Otolaryngology – Head & Neck Surgery, Washington University School of Medicine, USA. The Chair was supported by four steering committee members who were able to vote:

  • Professor René Gifford, VanderbiltUniversity, Nashville, USA;
  • Dr David Haynes, Vanderbilt University, Nashville, USA;
  • Professor Thomas Lenarz, Medical University of Hannover, Germany; and
  • Professor Gerard O’Donoghue, University of Nottingham, UK.

The Delphi panel comprised an additional 26 experts in the field of cochlear implant use (see Table 1 for full details).

In addition, a CAPAC of representatives from international cochlear implant user and professional advocacy organisations was involved in the development of the consensus statements. The CAPAC was formed to ensure the patient’s voice was considered in the Delphi consensus process. The seven CAPAC members provided feedback on the statements at each voting round but did not have a voting role in the Delphi process.

  • Dr Oliver Adunka, Ohio State University, Columbus, OH, USA
  • Dr Allison Biever, AuD, Rocky Mountain Ear Center, Englewood,CO, USA
  • Professor Robert Briggs, The University of Melbourne; Royal Victorian Eye and Ear Hospital; Royal Melbourne Hospital, Australia
  • Dr Matthew Carlson, Mayo Clinic School of Medicine, Rochester, MN, USA
  • Dr Pu Dai, PLA General Hospital, Beijing, China
  • Dr Colin Driscoll, Mayo Clinic School of Medicine, Rochester, MN, USA
  • Dr Howard Francis, Duke University School of Medicine, Durham, NC, USA
  • Dr Bruce Gantz, University of Iowa Health Care, Iowa City, IA, USA
  • Dr Richard Gurgel, University of Utah Hospitals and Clinics, Salt Lake City, UT, USA
  • Dr Marlan Hansen, The University of Iowa, Iowa City, IA, USA
  • Associate Professor Meredith Holcomb, Medical University of South Carolina, Charleston, SC, USA and University of Miami, FL, USA
  • Dr Eva Karltorp, Karolinska University Hospital, Stockholm, Sweden
  • Dr Milind Kirtane, Seth GS Medical College and KEM Hospital, Parel, Mumbai, India
  • Ms Jan Larky, Stanford University School of Medicine, CA, USA
  • Professor Emmanuel Mylanus, Radboud University Medical Center, Nijmegen, Netherlands
  • Dr Thomas Roland, New York University School of Medicine, New York, NY, USA
  • Professor Shakeel Saeed, University College Hospital; National Hospital for Neurology and Neurosurgery; Royal National Throat, Nose and Ear Hospital, London, UK
  • Professor Henryk Skarzynski,* Institute of Physiology and Pathology of Hearing, Warsaw, Poland
  • Professor Piotr Skarzynski,* Department of Teleaudiology and Screening, World Hearing Center, Institute of Physiology and Pathology of Hearing, Warsaw; Department of Heart Failure and Cardiac Rehabilitation, Medical University of Warsaw; Institute of Sensory Organs, Kajetany, Poland
  • Dr Mark Syms, Arizona Hearing Center, Phoenix, AZ, USA
  • Associate Professor Holly Teagle, University of Auckland, New Zealand
  • Professor Paul Van De Heyning, Antwerp University Hospital, University of Antwerp, Edegem, Belgium
  • Professor Christophe Vincent, Centre Hospitalier Regional, Universitaire de Lille, France
  • Professor Hao Wu, 9th Peoples Hospital, Jiao Tong University School of Medicine, Shanghai, China
  • Professor Tatsuya Yamasoba, The University of Tokyo Hospital, Japan
  • Dr Terry Zwolan, University of Michigan, Ann Arbor, MI, USA

CAPAC Co-Chairs

  • Barbara Kelley – Executive Director, Hearing Loss Association of America
  • Harald Seidler – Representative of the International Federation of Hard of Hearing People and immediate past President of the German Association of the Hard of Hearing (1996- 2019)

Professional Organisations

  • Professor Bernard Fraysse – President, International Federation of Otorhino Laryngological Societies (IFOS)
  • Professor George Tavartkiladze – Secretary General, International Society of Audiology (ISA)

User Advocacy Organisations

  • Leo De Raeve – special advisor to the board – European Association of Cochlear Implant Users (EURO-CIU)
  • Donna Sorkin – Executive Director, American Cochlear Implant Alliance (ACIA)
  • Darja Pajk – Treasurer – European Federation of Hard of Hearing People (EFHOH)


1. World Health Organization. Addressing the rising prevalence of hearing loss. 2018. Available from: (Accessed October 2018).
2. Mahboubi H. Gaps in evaluating, managing hearing difficulties. Hearing Journal 2018;71(3):6.
3. Sorkin DL. Cochlear implantation in the world’s largest medical device market: utilization and awareness of cochlear implants in the United States. Cochlear Implants Int 2013; 14 (Suppl 1):S4–12.
4. De Raeve L. Cochlear implants in Belgium: Prevalence in paediatric and adult cochlear implantation. Eur Ann Otorhinolaryngol Head Neck Dis 2016;133(Suppl 1):S57–60.
5. Woodcock K, Pole JD. Educational attainment, labour force status and injury: a comparison of Canadians with and without deafness and hearing loss. Int J Rehabil Res 2008;31(4):297–304.
6. Sung YK, Li L, Blake C, Betz J, Lin FR. Association of hearing loss and loneliness in older adults. J Aging Health 2016;28:979–94.
7. Mick P, Kawachi I, Lin FR. The association between hearing loss and social isolation in older adults. Otolaryngol Head Neck Surg 2014;150:378–84.