Special Report – The Clinical Effectiveness of Cochlear Implants by The Magazine Production Company

Special Report

The Clinical Effectiveness of Cochlear Implants Cochlear Implantation Implant Younger for Better Outcomes Implant Older for Better Outcomes Too? Later Life Implantation Bilateral Implantation: One Ear Good, Two Ears Better? NICE (National Institute for Clinical Excellence) Guidance on Cochlear Implantation and the Way Forward

Published by Global Business Media

A cochlear implant helped Glenn hear again when hearing aids were not enough… Discover how Glenn reclaimed his life through cochlear implants.

Cochlear Implants for adul ts

“Since the success of my implant I’ve had man special moments that y not have been poss would ible without the implant .” Rober t ‘Bud’ Morro w – CI Volunteer Advoc

Visit www.iwanttohear.co.uk and download the Adult Cochlear Implant Guide today.

Life before a Cochlear

Implant “At the age of 56 I suddenly lost my hearing. Nobo dy is quite sure why this happened and the best guess is that it was cause d by a virus. It was made worse by the fact that at the same time as losing my heari ng, I also lost my balan ce and developed severe tinnit us. I could no longer work .”

What is a Cochlear Implant?

ate

Life after a Cochlear

Implant

“The cochlear impla nt has helped me to get my life back again. I never expected to be able to return to my career, but since the implant I can carry on a norm al conversation when meet new people and I can ing use the phone quite well.”

Cochlear implants provide useful hearing to adults and children who get little or no benefit from a hearing aid. They consist of: The internal part: the receiver, surgically implanted in the mastoi d bone behind the ear, with electrodes inserte d into the inner ear, (cochlea). The external part: the microphone and speech processor conver an electrical signal which t sound into is sent to the electrodes in the inner ear. These then send the signal through the auditory nerve to the brain, where it is perceiv ed as sound.

The Ear Foundation

SPECIAL REPORT:THE CLINICAL EFFECTIVENESS OF COCHLEAR IMPLANTS

SPECIAL REPORT

The Clinical Effectiveness of Cochlear Implants Cochlear Implantation Implant Younger for Better Outcomes

Contents

Implant Older for Better Outcomes Too? Later Life Implantation Bilateral Implantation: One Ear Good, Two Ears Better? NICE (National Institute for Clinical Excellence) Guidance on Cochlear Implantation and the Way Forward

Foreword

Dr R A Sykes, Editor

Cochlear Implantation

Sue Archbold PhD, The Ear Foundation

Outcomes from Cochlear Implantation in Adults Outcomes from Cochlear Implantation in Children The Pathway to Implantation: Straightforward? Published by Global Business Media

Published by Global Business Media Global Business Media Limited 62 The Street Ashtead Surrey KT21 1AT United Kingdom Switchboard: +44 (0)1737 850 939 Fax: +44 (0)1737 851 952 Email: info@globalbusinessmedia.org Website: www.globalbusinessmedia.org Publisher Kevin Bell Business Development Director Marie-Anne Brooks Editor Dr R A Sykes Senior Project Manager Steve Banks Advertising Executives Michael McCarthy Abigail Coombes Production Manager Paul Davies For further information visit: www.globalbusinessmedia.org The opinions and views expressed in the editorial content in this publication are those of the authors alone and do not necessarily represent the views of any organisation with which they may be associated. Material in advertisements and promotional features may be considered to represent the views of the advertisers and promoters. The views and opinions expressed in this publication do not necessarily express the views of the Publishers or the Editor. While every care has been taken in the preparation of this publication, neither the Publishers nor the Editor are responsible for such opinions and views or for any inaccuracies in the articles.

© 2013. The entire contents of this publication are protected by copyright. Full details are available from the Publishers. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical photocopying, recording or otherwise, without the prior permission of the copyright owner.

Implant Younger for Better Outcomes

Dr R A Sykes, Editor

Benefits of Cochlear Implants in Children Comparing Implantation in the First Year of Life with Later Implantation A Sliding Scale of Benefit

Implant Older for Better Outcomes Too? Later Life Implantation

Dr R A Sykes, Editor

Cochlear Implantation in Advanced Age Adult Patients Positive Outcomes for Perceptive Ability Improvements Moving Forward

Bilateral Implantation: One Ear Good, Two Ears Better?

Susan Thomas, Medical Correspondent

Increased Vocalization and Listening in Children Improved Sensitivity to Sound, Speech Recognition, and Directionality in Adults Too The Head Shadow Effect and Low Frequency Preservation – New Considerations Quality of Life Conclusions: Two Implants Are Preferable To One

NICE (National Institute for Clinical Excellence) Guidance on Cochlear Implantation and the Way Forward

John Bushnell, Staff Writer

NICE Guidance – Subsequent Research Findings Strong Evidence Base Points to Improvement in Quality of Lives

References 15

www.primarycarereports.co.uk | 1

SPECIAL REPORT:THE CLINICAL EFFECTIVENESS OF COCHLEAR IMPLANTS

Foreword C

ochlear implants (CIs) are infrequently

advances are however leading to modifications to

seen devices that are being increasingly used

the indications for CI surgery8.

to improve the hearing of deaf people around the

This Special Report opens with an article by Sue

world. In the UK there are currently an estimated

Archibald of The Ear Foundation, which provides

11,000 cochlear implant users with an annual

an excellent overview of our current understanding

implantation rate of around 1200 patients that is

of both cochlear implantation and its role in the

fairly evenly distributed between adults (750) and

21st century. In particular, it highlights the key

children (450) . The indications for implantation

benefits that both adults and children can gain

are fairly straightforward; children are either born

from cochlear implantation. Of particular note, this

deaf enough to meet the criteria for implantation,

editorial discusses the failings of the current system

or develop it early in life (e.g. meningitis), and in

and barriers that exist in fully implementing the

adults, hearing either diminishes to such a degree

technology at the point of need. The report then

that an implant is warranted or they have other

moves on to review some of the key factors raised by

disabilities (such as blindness) that result in an

this editorial, and seeks to provide the reader with the

over dependence on their hearing. An outline of

necessary evidence and confidence to offer cochlear

the full NICE technology appraisal guidance of

implantation in target population. For example, earlier

2009 (reviewed 2011)2,3, are highlighted together

implantation in children is increasingly considered

with a full list of the current indications for CI.

to offer greater benefits over delayed implantation

Since its inception, cochlear implantation has

whilst, at the opposite end of the spectrum, it is

proven to be a safe, reliable and cost effective

suggested that implantation is not only suitable

treatment for people with severe deafness4,5,6,7

for older children and adults, but also for geriatric

with dramatic progress being made in its clinical

populations too. Furthermore, current research is

application. Todayâ&#x20AC;&#x2122;s modern CIs are advanced pieces

increasingly pointing toward the added benefits of

of technology that use multi-channel electrodes with

two implants over one. The research underpinning

highly miniaturized and powerful digital processing

these assertions is outlined in this report.

chips. Overall, it is now considered as fact that implantation provides better outcomes than hearing aids in the severe to profoundly deaf. The increasingly favourable clinical outcomes arising from new

Robert Sykes Editor

Dr Robert Sykes qualified with a degree in medicine (MBChB Honours) in 2004 from the University of Liverpool where he was awarded the George Holt Medal for high academic achievement, along with commendations for a number of his clinical reviews. As a postgraduate he entered into a GP vocational training scheme before opting to work in a portfolio career, and in 2008, he set up Northern Editing (www.docrob.co.uk/nothernediting) for medical writing and editing. Currently, he is also the Executive Editor for the UKâ&#x20AC;&#x2122;s only peer support organisation for doctors with mental illness, the Doctorsâ&#x20AC;&#x2122; Support Network (registered charity 1103741; www.dsn.org.uk).

2 | www.primarycarereports.co.uk

SPECIAL REPORT:THE CLINICAL EFFECTIVENESS OF COCHLEAR IMPLANTS

Cochlear implantation Sue Archbold PhD, The Ear Foundation Transforming opportunities for deaf adults and children

here are an estimated 10 million deaf people in the United Kingdom: about 1 in 6 of the population. There are 45,000 deaf children and young people in the UK, with about 1 in 1,000 deaf by the age of three. Of the adult population over 70 years of age, 70% of them will have some degree of hearing loss. Deafness, in adulthood or childhood, has a profound but often unrecognised impact on communication skills with consequences for education, employment, and quality of life. The World Health Organisation predicts that by 2030 adult onset hearing loss will be in the top 10 disease burdens in high and middle income countries1. Yet, it often goes untreated. Language develops through hearing conversation of the family: deafness in childhood makes language learning difficult, and has a huge impact on educational attainments. Deaf children typically left school with reading ages of nine, and little has changed until recently, with the impact of cochlear implantation. For adults, losing your hearing makes communication and maintaining an independent and active life in the community difficult, often leading to social isolation and mental health issues. Becoming deaf more than doubles the chances of depression in older people and is linked to increased risk of dementia2, and greater risk of unemployment1. Cochlear implantation, introduced to the UK in the 1980â&#x20AC;&#x2122;s, has transformed the opportunities for children and adults with hearing loss. Cochlear implant systems consist of two parts: the internal receiver surgically implanted into the mastoid bone with the electrodes implanted into the cochlea, or inner ear, and the speech processor, microphone and transmitter worn externally. Figure 1. The acoustic signal is converted into electrical signals by the speech processor(1), which are transmitted through the skin to the receiver(2), and thus to the electrodes(3) in the cochlea (4).

figure 1. Hearing with a Cochlear Implant

Deafness, in adulthood or childhood, has a profound but often unrecognised impact on communication skills with consequences for education, employment, and quality of life.

Thus, even those who cannot benefit from conventional hearing aids can benefit from cochlear implantation stimulating the auditory nerve directly. Those who are profoundly deaf can obtain aided hearing thresholds of about

www.primarycarereports.co.uk | 3

SPECIAL REPORT:THE CLINICAL EFFECTIVENESS OF COCHLEAR IMPLANTS

Simultaneous bilateral implantation has been shown to be more effective in the development of early communication skills.

25dB enabling them to hear the entire range of speech frequencies. Today about 450 children and 500 adults are implanted annually in the UK. Initially only one ear was implanted, as of 2009 NICE guidelines recommend simultaneous bilateral implantation for children, and for adults who have another condition such as blindness to make spatial awareness vital (nice.org.uk/TA166).

Outcomes from Cochlear Implantation in Adults Cochlear implants have been shown to be reliable3, and with low levels of complications4. In restoring useful hearing to those who had been deafened, cochlear implantation has provided improved speech perception5,6, the ability to use the telephone7, to participate in conversation, and a quality of life similar to that of the general population8. Increasingly adults who have been born deaf are considering implantation; those who have used hearing aids and use spoken language are more likely to benefit. Cochlear implantation is also considered effective in the elderly population, overcoming the impact of hearing loss, with age not a barrier to implantation9. Research also indicates that those with deafness in one ear only are a population for whom cochlear implantation can also be of benefit.10

Outcomes from Cochlear Implantation in Children Children are increasingly being implanted safely in the first year of life11, and where there are no other difficulties they are developing spoken language comparable with their hearing peers12. More deaf children with implants are going to mainstream schools13 and cochlear implantation has improved educational attainments14, 15 and literacy skills.16 Long term use-age rates among young people are high17 and studies reveal that the quality of life of deaf young people with cochlear implants is similar to that of their hearing peers18. Up to 40% of deaf children are likely to have another difficulty and these complex children are increasingly considered for implantation, and found to benefit19. Hearing in both ears improves hearing in noise and the ability to localise sound; important in both children and adults. Simultaneous bilateral implantation has been shown to be more effective in the development of early communication skills20; however, where the second implant is provided some time after the first, adjustment is likely to take time before benefit is seen21.

The Pathway to Implantation: Straightforward? The cost-effectiveness of cochlear implantation 4 | www.primarycarereports.co.uk

in both adults and children has been intensively studied and is well established22,23. Unilateral cochlear implantation has been shown to be cost-effective in both adults and children5; and simultaneous bilateral cochlear implantation in children (nice.org.uk/TA166). While benefit from implantation has been well established, outcomes can vary in this heterogeneous population, but a major predictor of benefit is length of deafness, or, in born deaf children, age at implantation. This makes referral for timely assessment vital to ensure full benefit from this intervention; there is some evidence that this is not happening. We know that 45% of those who visit their GP about their hearing loss are not referred for audiological assessment1: we know that for parents, the path to implantation from early diagnosis of deafness is not straightforward. For children with more complex needs referral is likely to be even more delayed, making them doubly disadvantaged. Figure 2 shows that, in the UK, we particularly lag behind other countries in the implantation of adults. For example, in Germany 35 patients per million of the population receive an implant as opposed to only 11 patients per million of the population in the UK. As the incidence of hearing loss and those likely to benefit from a cochlear implant is similar in the two countries this demonstrates the poor take up of cochlear implantation in the UK as compared to other developed countries. This may reflect the lack of awareness of the impact of hearing loss in general, and of this intervention in particular. There is a great deal of information available: the website of National Cochlear Implant Users Association (www.nciua.org) has a useful site called â&#x20AC;&#x153;Get one!â&#x20AC;? and a helpful DVD for GPs. The care pathways for implantation are given at www.mapofmedicine.com for both adults and children. The British Cochlear Implant Group (www.bcig.org.uk) provides details of the implanting centres in the UK, and The Ear Foundation website (www.earfoundation.org.uk) provides information about cochlear implantation, and up to date research.

FIGURE 2. Implants per million by demographic structure per country per million (Adult/Child)

Cochlear implantation has now been an established, cost effective provision for both

SPECIAL REPORT:THE CLINICAL EFFECTIVENESS OF COCHLEAR IMPLANTS

adults and children in the UK for over 20 years, but adoption remains low, particularly for adults. Age need not be a barrier to implantation: both infants and those who are elderly can benefit. It is vital for those who could potentially benefit to have easy access to up-to-date information from professionals to purchasers, and the public on both the impact and incidence of hearing loss and in particular on the proven outcomes of cochlear implantation.

About The Ear Foundation The Ear Foundation is an independent charity that helps deaf people and their families make the best use of technology to improve hearing, communication and spoken language. They also carry out child and family-centred research in the field of cochlear implantation and other hearing technologies.

About Cochlear Cochlear is the global leader in implantable hearing solutions. It has a dedicated global team of 2,200 people who deliver the gift of sound to the hearing impaired in over 100 countries. Its vision is to connect people, young and old, to a world of sound by offering life enhancing hearing solutions. Cochlear’s mission of “Hear now. And always” embodies the company’s commitment to providing its recipients with the best possible hearing performance today and for the rest of their lives. Over 25 years Cochlear has helped over 230,000 people either hear for the first time or reconnect them to their families, friends, workplaces and communities.

Cochlear implantation has now been an established, cost effective provision for both adults and children in the UK for over 20 years, but adoption remains low, particularly for adults.

For more information, contact: Cochlear Europe Ltd Contact: Brian Walshe Email: bwalshe@cochlear.com Phone: +44 1932 87 1011 www.cochlear.com Ear Foundation Contact: Sue Archbold,PhD Email: sue@earfoundation.org.uk Phone: +44 (0)115 942 1985 www.earfoundation.org.uk

www.primarycarereports.co.uk | 5

SPECIAL REPORT:THE CLINICAL EFFECTIVENESS OF COCHLEAR IMPLANTS

References 1

Action on Hearing Loss (2011) Annual report

Lin FR, Metter EJ, O’Brien RJ, Resnick SM, Zonderman AB, Ferrucci L (2010) Hearing Loss and Incident Dementia.

Arch Neurol. Vol 68 No 2 . 214-220 Battmer RD, O’Donoghue GM, Lenarz T.(2007) A multicenter study of device failure in European cochlear implant centers. Ear & Hearing.

Venail F, Sicard M, Piron JP et al. (2008) Reliability and complications of 500 consecutive cochlear implantations. Archives of Otolaryngology –

Head & Neck Surgery. 134. 1276-1281 M Bond, S Mealing, R Anderson, J Elston, G Weiner, RS Taylor, M Hoyle, Z Liu, A Price and K Stein (2009) The effectiveness and cost-effectiveness

of cochlear implants for severe to profound deafness in children and adults: a systematic review and economic model. HTA vol13.No44 UKCISG (2004). Criteria of candidacy for unilateral cochlear implantation in postlingually deafened adults. I: Theory and measures of effectiveness.

Ear & Hearing 25: 310-350 Clinkard D, Shipp D, Friesen LM, Stewart S, Ostroff J, Chen JM, Nedzelski JM, Lin VY. (2011) Telephone use and the factors influencing it among

cochlear implant patients. Cochlear Implants International. 12 (3) 140-6 Rembar SH, Lind O, Romundstad P, Helvik AS. 2012;. Psychological well-being among cochlear implant users: a comparison with the general

population. Cochlear Implants International. 13(1):41-9 Luntz M, Yehudai N, Most T, Shpak T (2012) Cochlear implantation in the Elderly: Surgical and Hearing Outcomes. Audiology and Neurotology.

vol 17. Suppl 1 K amal SM, Robinson AD, Diaz RC (2012) Cochlear Implants in Single-sided deafnes for enhancement of sound localization and speech

perception. Curr Opin Otolaryringology HN Surgery. 20 (5) 393-7 DettmanSJ, PinderD, Briggs RJ, Dowell RC, Leigh JR. Ear Hear. 2007 28(2 Suppl):11S-18S.

Tait ME, Nikolopoulos TP, Lutman ME (2007) Age at implantation and development of vocal and auditory preverbal skills in implanted deaf children.

International journal of pediatric otorhinolaryngology. 71:603-610 Archbold SM, Nikolopoulos TP, Lutman ME, O’Donoghue G M (2002) The educational settings of profoundly deaf children with cochlear implants

compared with age-matched peers with hearing aids: implications for management. International Journal of Audiology. 41(3); pp 157-161 Stacey PC, Fortnum H, Barton G, Summerfield AQ (2006) Hearing Impaired Children in UK 1: Auditory Performance, Communication Skills,

Educational Achievement, Quality of Life and Cochlear Implantation. Ear & Hearing. 27,161-186 Thouthenhoofd E (2006) Cochlear Implanted Pupils in Scottish Schools: 4 Year School Attainment Data (2000-2004). The Journal of Deaf Studies

and Deaf Education 11,2:171-188 Archbold SM, Harris M, O’Donoghue G, Nikolopous, White A, Richmond HL (2008) Reading abilities after cochlear implantation: the effect of age

at implantation on outcomes at 5 and 7 year implantation. In J Pediatr Otorhinolaryngol. 72 (10): 1471-8 Archbold SM, Nikolopoulos TP, Lloyd-Richmond H( 2009) Long-term use of cochlear implant systems in paediatric recipients and factors

contributing to non-use. Cochlear Implants International. 10(1); 25-40 Mance J, Edwards L. Deafness-related self-perceptions and psychological well-being

in deaf adolescents with cochlear implants (2012) Cochlear Implants International 2012;13(2):93-104. N ikolopoulos, TP, Archbold, SM, Wever, CC, Lloyd, H. Speech production in deaf implanted children with additional disabilities and comparision

with age-equivalent implanted children without such disorders. (2008) Int J Pediatr Otorhinolaryngol 72(12) 1823-1828. Tait M, Nikolopoulos TP, De Raeve L, Johnson S, Datta G, Karltorp E, Ostlund E,

Johannsen U, Van Knegsel E, Mylanus EAM, Gulpen PMH, Beers M, Frijn JHM (2010) Bilateral versus unilateral cochlear implantation in young children. Int Jnl Ped Otorhinolaryngology, 74, 206-111 Mather J, Archbold S, Gregory S (2011) The experiences of Deaf Young People with Sequential Bilateral Cochlear Implants. Deafness and

Education International. Vol 13, no 4, 152- 172 UK Cochlear Implant Study Group (2004) Criteria of candidacy for unilateral cochlear implantation in post-lingually deafened adults.

11 Cost-effectiveness analysis. Ear & Hearing 25 (4) 336-360 Barton GR, Stacey P, Fortnum H, Summerfield A (2006) Hearing-impaired children in the United Kingdom, IV: cost-effectiveness of pediatric

cochlear implantation. Ear and hearing. 27 (5): 575-588 6 | www.primarycarereports.co.uk

SPECIAL REPORT:THE CLINICAL EFFECTIVENESS OF COCHLEAR IMPLANTS

Implant Younger for Better Outcomes Dr Robert Sykes, Editor

n the UK, there are approximately 45,000 deaf children with an annual incidence of around 450 cases1,9,10,11. The use of cochlear implantation in this population is now well established, a point underscored by an overwhelming research base, with one clinical review in 2011 finding 929 references in the literature12. The rationale for using CIs is so well established12 that most current research focuses only on addressing the specific ways that greater benefit can be gained. One such improvement that has been considered is implanting as early as possible.

Benefits of Cochlear Implants in Children Several prospective/follow-up studies have looked at this question using the outcome measures sensitivity to sound13,14, speech perception15,16,17 and speech production18,19, in the over 2 age group. The latter two measures have each demonstrated some degree of benefit with earlier age at implantation when compared with either â&#x20AC;&#x153;no technological

supportâ&#x20AC;? or a simple acoustic hearing aid. A positive trend in favour of earlier implantation20 with specific regard to English grammar (n = 82)21 has for example been found in children aged between 2 and 13 years. An earlier study by Nikolopoulos et al18, also found significant negative correlations with age at implantation at 3 and 4 years on several measures of auditory performance, suggesting that increased benefit may come from earlier implantation. A large study further (n = 297)17 reported that their CI group improved greatest over an 18 month follow up when implantation occurred before 6 years of age, than for those aged between 6 and 12 years. Results for speech production were similarly positive; finding that at 4 years post activation there was a significant correlation between earlier implantation and better speech production18. Although individually small in sample size, the cumulative numbers studied and universally demonstrated improvements in hearing encourage an earlier implantation of CIs. More recently, research has demonstrated that even earlier implantation may be warranted.

TABLE 1: Evidenced Benefits of Earlier Implantation The greatest benefits are found in the under 18 month age group, but benefits continue well beyond this range Implantation under 18 months (compared with implantation at 18-25 months) Improved perceptive abilities25 Increased speed in attaining language outcomes28,29 Better results comprehension and voice production6,27 Improved expressive and receptive language26 Implantation before age two years (compared with implementation at approx 2-6 years) Two researchers30,31 have observed globally improved results Implantation in 3-4 year olds One researcher recorded better results in those implanted before three years of age14 Improved verbal perception and language development when performed in the third year13 Improved grammar when performed in the fourth year21

www.primarycarereports.co.uk | 7

SPECIAL REPORT:THE CLINICAL EFFECTIVENESS OF COCHLEAR IMPLANTS

It appears that maximum benefits appear when implantation occurs before 18 months but there is probably The electrode matches the natural shape of the cochlea to sit in the hearing zone, close to the

a sliding scale of benefit; with increasing ageâ&#x20AC;&#x2122;s still gaining benefits in primary language development.

spiral ganglion cells.

Comparing Implantation in the First Year of Life with Later Implantation Few studies in the literature have compared children implanted within the first year of life, to those implanted between 12 and 24 months. Those that have, are very encouraging. Dettman22 for example, observed improved language outcomes similar to that of their peers, in children implanted within the first year compared to those implanted between 12 and 24 months. However, it was not clear whether this advantage would be retained over time. Adding to this, statistically significant results in terms of better and more rapid development of verbal perception, receptive language and verbal understanding in children implanted within the first year of life, compared to those implanted in the second and third years, have also been demonstrated23. Table 1 summarizes the key benefits that can be obtained from earlier implantation.13,14,21,24,26,27,28,29,30,31

A Sliding Scale of Benefit There is no doubt that cochlear implantation is safe and effective for children; it improves the ability to understand and produce speech compared with acoustic hearing aids or non technological support, leading to an increased likelihood of mainstream education and better educational outcomes. Moreover, these benefits are found to be greater with earlier implantation. It appears that maximum benefits appear when implantation occurs before 18 months but there is probably a sliding scale of benefit; with increasing ageâ&#x20AC;&#x2122;s still gaining benefits in primary language development (Table 1). The key to maximal benefits from CIs appear to come from implantation as early as possible. 8 | www.primarycarereports.co.uk

SPECIAL REPORT:THE CLINICAL EFFECTIVENESS OF COCHLEAR IMPLANTS

Implant Older for Better Outcomes Too? Later Life Implantation Dr Robert Sykes, Editor

earing loss is a common and disabling consequence of the aging process, particularly when superimposed on other age-related conditions. Presbycusis (age-related hearing loss) can increase social isolation and associated sequelae, with the increasing cognitive demand of verbal communication and the diminished sense of social and physical connectedness contributing to a feeling of vulnerability that deteriorates with time32. In the UK, there are around 6,390,500 retired adults with some degree of deafness, and a further 685,000 with severe to profound deafness9. The number of severe to profoundly deaf adults of retirement age is approximately five times that of the working age population9. With an ever aging population that is increasingly extending the years of productive life, this represents an eminently remedial factor. The benefits of CIs in adult populations have been demonstrated, and are not in doubt when assessed against the key outcome measures of improved speech perception and production33,34,34. The pre-lingually deaf have tended to gain the least benefit in research, as have those who have been deaf for over 30 years pre-implantation36. More recent evidence has also suggested that significant benefits may still exist for adults and adolescents with early onset and pre-lingual deafness , although the evidence is still in favour of post-lingually deafened patients gaining the greatest benefits . It therefore stands to reason that those who have acquired deafness throughout life, or whose hearing has deteriorated, should benefit from cochlear implantation, and several studies have looked into this very question.

Cochlear Implantation in Advanced Age Adult Patients CIs have tended to be excluded from the geriatric population on the assumptions that physiological deterioration of cognitive abilities may have an impact on speech perception post implantation, and that there would be problems

â&#x20AC;&#x153;The age of a cochlear

implant candidate should

not be a factor in the

candidacy decision-

making process... the QoL

of elderly recipients was

significantly improved after

cochlear implantation.â&#x20AC;? regarding tolerance, plus the increased risk of complications and difficulties in manipulating the external components of the device 35. More recently however, this has begun to change, and some studies have refuted these claims and demonstrated real improvements in Quality of Life (QoL). In 2004, for example, the UK Cochlear Implant Study Group (UKCISG) established that the CI procedure is costeffective even in patients implanted after the age of 70 years37. www.primarycarereports.co.uk | 9

SPECIAL REPORT:THE CLINICAL EFFECTIVENESS OF COCHLEAR IMPLANTS

Positive Outcomes for Perceptive Ability Several studies have now confirmed that improvements can be obtained in speech perception/recognition abilities38,39,40,41,42,43,44 with the majority revealing that there were no statistically significant differences between elderly and young adult patients. The results however were not universally favourable. In three studies, although benefits were clearly seen, perceptive results were slightly inferior in elderly implanted patients 41,42,43 . It is nevertheless encouraging that the results could not deny some benefit for elderly (>65 years old) implantation.

Improvements The data in this area is positive, but mixed. In one study, subjective perception of depression and loneliness were improved43 in adult patients implanted at an advanced age. Similar findings have appeared elsewhere in the literature. Statistically significant improvements in the QoL of elderly patients have been documented44, for example, concluding that â&#x20AC;&#x153;the age of a cochlear implant candidate should not be a factor in the candidacy decisionmaking process... (and that)... the QoL of elderly recipients was significantly improved after cochlear implantation.â&#x20AC;? Elsewhere36, although overall results once again favoured cochlear implantation, the association between, age at implantation and duration of deafness was slightly more nuanced. Here, several measures declined significantly with age at implantation. Furthermore it demonstrated a strong effect on both speech perception and when related to the duration of preceding deafness. In broad terms, a greater effectiveness was associated with earlier implantation and this effectiveness declined with the duration of deafness across all age groups.

Moving Forward There is accumulating evidence of a potential role for cochlear implantation in older adults with poor word understanding despite conventional hearing aid use. It may be possible to get very real benefits from restoring the communication capacity in the deaf and hardof-hearing geriatric population32. Generally, there is also no upper age limit over which CI is contraindicated, that is reported in any of the reviews considered. Having said that, 30 years of preceding pre-lingual deafness is probably a good cut off for exclusion. Although the NICE guidelines on this issue are equivocal, there is a movement toward offering CIs in the elderly population2. 10 | www.primarycarereports.co.uk

There is accumulating evidence of a potential role for cochlear implantation in older adults with poor word understanding despite conventional hearing aid use. It may be possible to get very real benefits from restoring the communication capacity in the deaf and hard-of-hearing geriatric population.

SPECIAL REPORT:THE CLINICAL EFFECTIVENESS OF COCHLEAR IMPLANTS

Bilateral Implantation: One Ear Good, Two Ears Better? Susan Thomas, Medical Correspondent

ochlear implantation is the currently accepted gold-standard for hearing improvement2. Until recently, binaural stimulation with one implant and one standard acoustic hearing aid was considered best practice38 based on cost benefit analyses, with data clearly indicating that advantages could be obtained from this method39. However, this has led to the natural proposition; if a hearing aid in the non implanted ear presents benefits, then surely a second CI could provide even greater benefit. A number of studies from the UK, Europe and the USA have looked into the suitability, cost-effectiveness and potential advantages of bilateral implantation in both child and adult populations.

Increased Vocalization and Listening in Children The major studies in the literature are crosssectional/repeated measure studies from the USA40,41,42. All concluded that bilaterally implanted children were significantly better than children with one implant plus a hearing aid in all three test areas of sensitivity to sound50,51,52 speech perception50 and speech production52. However, although there is no convincing data to contradict these results, the small sample sizes (n=2050), poor design, and a lack of consideration of confounding factors meant that the evidence from them could not be broadly generalized. Nevertheless, based on this initial success, it seemed that there was probably an additional benefit for children from having two CIs37. Two studies published in 2010 43,44 have indeed confirmed the reliability of this initial data and placed it in practical context. Profoundly deaf bilaterally implanted children are, for example, more likely to use vocalization to communicate53, and to listen more effectively53,54, compared with unilaterally implanted children. Importantly, these results are independent of age at implantation and length of preceding deafness53.

Improved Sensitivity to Sound, Speech Recognition, and Directionality in Adults Too Results on the sensitivity to sound and speech perception has tended to demonstrate a binaural

The advantages of bilateral CIs correspond with the primary benefits of bilateral hearing, that is, improved speech perception in quiet and in noise.â&#x20AC;? advantage 43,44,45,46. Summerfield et al (n = 24)55, measured self-reported spatial hearing, hearing quality and speech-specific hearing with a significant benefit for spatial hearing in particular, at 3 and 9 months post bilateral CI. Additionally, it was reported by Verschuur and colleagues (n = 20)56 that bilaterally aided participants make significantly fewer errors in sound direction detection, regardless of where speakers are positioned.

The Head Shadow Effect and Low Frequency Preservation â&#x20AC;&#x201C; New Considerations Litovsky and colleagues (n = 37)57 measured speech perception in simultaneously implanted adults, finding significant binaural gains in all outcomes. In particular, bilaterally implanted participants were able to improve the head shadow effect when in noise (which occurs when speech and noise come from different directions producing a difference in hearing www.primarycarereports.co.uk | 11

SPECIAL REPORT:THE CLINICAL EFFECTIVENESS OF COCHLEAR IMPLANTS

Bilateral cochlear implantation is currently the closest Cochlear Nucleus System

approximation we can give a deaf person to “normal” hearing, and the evidence base for its use is growing.

12 | www.primarycarereports.co.uk

because of the presence of the patients head). When speech reception thresholds were compared for bilateral implants versus either ear unilaterally there was a significant gain for bilateral versus unilateral implants. An earlier RCT in sequentially implanted adults similarly evidenced the benefits of bilateral implantation and supports this observation58. More recent reports published in 2012 have underscored these benefits, especially when placed in the context of hearing preservation surgery8,47,48,49 and offer additional hope to many deaf people.

Quality of Life The question as to whether or not there is a specific benefit from bilateral implantation with regards to QoL has been addressed in three studies using both generic and disease-specific instruments. Summerfield et al (n = 24)55 found that on one of five instruments, there was a strong bias in favour of bilateral implantation at five months post-implantation. The other instruments showed neutral or negative mean differences; deeper analysis however revealed that these results were associated with worsening

tinnitus after the second implantation, which the researchers felt negated the positive benefits of improved hearing. In another study (n = 37)57, significant gains were found for bilateral implantation, without worsening tinnitus. Finally, in response to the NICE guidance 20092 which highlighted the need for more information on the benefits of a second (sequential) implant, the RNID (Royal National Institute for Deaf People – now Action on Hearing Loss) sponsored a qualitative study addressing the issue50. Although those that persevered had positive outcomes, most struggled at various stages along the way. Nevertheless, all participants stated that they would recommend a second implant to another teenager despite the difficulties they had experienced62. Long term research is still very much needed to answer this question fully.

Conclusions: Two Implants Are Preferable To One Although the data is somewhat limited by methodological problems, it universally demonstrates a binaural advantage over unilateral implantation with a standard contralateral hearing aid. Indeed, as put by a 2010 review paper 51 “… the advantages of bilateral CIs correspond with the primary benefits of bilateral hearing, that is, improved speech perception in quiet and in noise.” We are designed as a species to use both of our ears equally, and this is key to our spatial awareness and in recognizing the directionality of sound. Bilateral cochlear implantation is currently the closest approximation we can give a deaf person to “normal” hearing, and the evidence base for its use is growing.

SPECIAL REPORT:THE CLINICAL EFFECTIVENESS OF COCHLEAR IMPLANTS

NICE (National Institute for Clinical Excellence) Guidance on Cochlear Implantation and the Way Forward John Bushnell, Staff Writer

n 2009 NICE completed a technology appraisal that examined the evidence for the devices currently available for cochlear implantation2. The official NICE guidance that resulted is as follows: 1. U nilateral cochlear implantation is recommended as an option for people with severe to profound deafness who do not receive adequate benefit from acoustic hearing aids (see point 5). It recommends that the cheapest comparable device should always be used, but stresses that this should take into consideration the long term support packages offered and not only the initial cost. 2. Simultaneous bilateral cochlear implantation can be considered as an option for both children with severe to profound deafness (who do not receive adequate benefit from acoustic hearing aids; see point 5), but also adults (specifically, those who are blind or who have other disabilities that increase their reliance on hearing for spatial awareness, and who also fail to receive adequate benefit from their standard hearing aids). 3. The report recommended against sequential bilateral cochlear implantation (bilateral implants where a second CI is implanted at a later date, and operation). However, this was explicitly placed for later review. 4. Those patients who had a unilateral implant before 2009 and who fall into one of the categories in point 2 however, were to be given the option of an additional contra-lateral implant if sufficient benefit could be demonstrated by the clinical team. 5. For the purposes of the guidance i. Severe to profound deafness was defined as the ability to only hear sounds that are louder than 90 dB HL at frequencies of 2 to 4 kHz without acoustic hearing aids.

ii. Adequate benefit from acoustic hearing aids was defined for the purposes of this guidance as: • A dults: a score of 50% or greater on Bamford–Kowal–Bench (BKB) sentence testing at a sound intensity of 70 dB SPL • C hildren: speech, language and listening skills appropriate to age, developmental stage and cognitive ability 6. Cochlear implantation should be considered in all groups, only after a full multidisciplinary team (MDT) assessment. This assessment should also include a valid trial of an acoustic hearing aid for at least 3 months (unless contraindicated or inappropriate). 7. When assessing the adequacy of acoustic hearing aids, the MDT should be mindful of the need to ensure equality of access. Tests, for example, may need to be adjusted according to a patients disabilities (e.g. physical and cognitive impairments), or communication difficulties (e.g. language). Other methods of assessment should be considered where equality cannot be guaranteed. This Guidance was reviewed in 2011, with a specific remit to consider several key aspects highlighted in the initial report. Firstly, to assess any new research on the benefits of bilateral cochlear implantation compared with unilateral cochlear implantation, specifically in adults with severe to profound deafness. Secondly, that data on the health-related QoL for children with bilateral CIs should be considered. However, the review statement in 2011 concluded that no new evidence had been published in these areas necessitating a review of the guidance3,52. As a consequence, the NICE technology appraisal on cochlear implantation was placed on the static list of guidance in June 2011; topics on this list may be transferred back to the active list for www.primarycarereports.co.uk | 13

SPECIAL REPORT:THE CLINICAL EFFECTIVENESS OF COCHLEAR IMPLANTS

further appraisal if new evidence becomes available, as has been happening over the interim period.

Given the continued

NICE Guidance – Subsequent Research Findings

expansion in the area of

Furthermore, the questions posed by NICE were not the only ones relevant when considering cochlear implantation. Seven important pieces of research were identified in the interim period between 2009 and 2011 by the British Cochlear Implant Group (BCIG)53,54,55,56,57,58. It should also be noted that some research was not recorded in the list of “on-going” investigations by NICE prior to placing their technology appraisal on the static list64. This includes the developing area of hearing preservation surgery, in which advances may allow for the preservation of patients’ residual hearing in the lower frequencies even after implantation of a cochlear device, thus providing patients with more natural hearing8,59,60,61.

Strong Evidence Base Points to Improvement in Quality of Lives The benefits to both the deaf individual and to wider society of our increasing experience with CIs are obvious to all. Children who receive CIs at younger ages are more likely to be able to enjoy a mainstream education, which therefore reduces the burden to society of a separate infrastructure, whilst simultaneously improving educational attainment. For adults, the benefits of increased independence and improved communication skills cannot be underestimated in any social or work environment. Given the continued expansion in the area of cochlear implantation, and the strong evidence base, the technology is set to become ever more important in improving the quality of lives of deaf children and adults alike. Getting treatment earlier is the key to this, but benefits can be gained at any age. The information sheet “Cochlear Implants: 20111” by the Ear Foundation (www.theearfoundation.org.uk), in association with Cochlear Europe Ltd (Surrey, UK), provides an excellent summary of the current evidence and key questions that is accessible for both clinicians and patients alike.

14 | www.primarycarereports.co.uk

cochlear implantation, and the strong evidence base, the technology is set to become ever more important in improving the quality of lives of deaf children and adults alike.

SPECIAL REPORT:THE CLINICAL EFFECTIVENESS OF COCHLEAR IMPLANTS

References: The Ear Foundation (in association with cochlear). Cochlear Implant Information Sheet. Available at: http://www.earfoundation.org.uk/cochlear-implants/

cochlear-implant-information-sheet 2

Cochlear implants for children and adults with severe to profound deafness. NICE technology appraisal guidance 166 (TA166) Issue date: January

Appendix A: decision paper presented to the Institute’s Guidance Executive. 04 July 2011.

2009. Available at: http://www.nice.org.uk/nicemedia/live/12122/42854/42854.pdf

Available: http://www.nice.org.uk/nicemedia/live/12122/55227/55227.pdf

Battmer RD, et al. A multicenter study of device failure in European cochlear implant centers. Ear Hear. 2007 28:95s-99s

Venail F, et al. Reliability and complications of 500 consecutive cochlear implants. Archives of otolaryngology – Head and neck surgery. 2008.

134:1276-1281. 6

Barton G et al. Hearing Impaired Children in the United Kingdom: cost effectiveness of paediatric cochlear implantation.

Ear and Hearing. 27(5): 575-588. UK cochlear Implant Study Group. Criteria of candidacy for unilateral cochlear implantation in post-lingually deaf adults. Cost effectiveness analysis.

Ear and Hearing. 25(4): 336-360. Eshraghi AA, et al. Biomedical engineering principles of modern cochlear implants and recent surgical innovations. Anat Rec (Hoboken).

2012 Nov; 295(11):1957-66. Action on hearing loss Facts and figures on deafness and tinnitus, Action on Hearing Loss Information, July 2011.

Available at: http://www.actiononhearingloss.org.uk/your-hearing/about-deafness-and-hearing-loss/statistics.aspx Fortnum HM, et al. Prevalence of permanent childhood hearing impairment in the United Kingdom and implications for universal neonatal hearing screening: questionnaire-based ascertainment study [see comment]. Br Med J 2001;323:536–40.

Davis A, et al. A critical review of the role of neonatal screening in the detection of hearing impairment. Health Technol Assess 1997;1(10).

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3262414/

F. Forli, et al. Systematic review of the literature on the clinical effectiveness of the cochlear implant procedure in paediatric patients. Acta Otorhinolaryngol Ital. 2011 October; 31(5): 281–298. 13

Manrique M, et al. Prospective long-term auditory results of cochlear implantation in prelinguistically deafened children: the importance of early

Manrique M, et al. Advantages of cochlear implantation in prelingual deaf children before 2 years of age when compared with later implantation.

implantation. Acta Otolaryngol Suppl 2004;(552):55–63. Laryngoscope 2004;114:1462–9. 15

Staller S, et al. Pediatric outcomes with the nucleus 24 contour: North American clinical trial. Ann Otol Rhinol Laryngol Suppl 2002;189:56–61.

Kessler DK, Osberger MJ, Boyle P. CLARION patient performance: an update on the adult and children’s clinical trials.

Scand Audiol Suppl 1997;47:45–9.

Svirsky MA, Meyer TA. Comparison of speech perception in pediatric CLARION cochlear implant and hearing aid users. Ann Otol Rhinol Laryngol Suppl

1999;177:104–9. 18

Nikolopoulos TP, et al. Age at implantation: its importance in pediatric cochlear implantation. Laryngoscope 1999;109:595–9.

Tomblin JB, Spencer et al. A comparison of language achievement in children with cochlear implants and children using hearing aids.

J Speech Lang Hear Res 1999;42:497–511. Harrison RV, Gordon KA, Mount RJ. Is there a critical period for cochlear implantation in congenitally deaf children? Analyses of hearing and speech perception performance after implantation. Dev Psychobiol 2005;46:252–61.

Nikolopoulos et al. Development of spoken language grammar following cochlear implantation in prelingually deaf children. Arch Otolaryngol Head

Dettman SJ, et al. Communication development in children who receive the cochlear implant younger than 12 months: risks versus benefits. Ear 2007

Neck Surg 2004;130:629–33. Apr;28(2 Suppl):11S-18S. 23

Colletti L. Long-term follow-up of infants (4-11 months) fitted with cochlear implants. Acta Otolaryngol. 2009 Apr;129(4):361-6.

Miyamoto RT, et al. Language skills of profoundly deaf children who received cochlear implants under 12 months of age: preliminary. Acta Otolaryngol. 2008 Apr; 128(4):373-7.

McConkey Robbins A, et al. Effect of age at cochlear implantation on auditory skill development in infants and toddlers. Arch Otolaryngol Head Neck

Holt RF, Svirsky MA. An exploratory look at pediatric cochlear implantation: is earliest always best? Ear Hearing. 2008;29:492–511.

Svirsky MA, et al. Development of language and speech perception in congenitally, profoundly deaf children as a function of age at cochlear

Novak MA, et al. Cochlear implants in infants and toddlers. Ann Otol Rhinol Laryngol Suppl. 2000 Dec; 185():46-9

Niparko JK, Tobey et al.CDaCI Investigative Team. Spoken language development in children following cochlear implantation. JAMA. 2010 Apr 21;

Nicholas JG, Geers AE. Will they catch up? The role of age at cochlear implantation in the spoken language development of children with severe to

Surg. 2004 May; 130(5):570-4

implantation. Audiol Neurootol. 2004 Jul-Aug; 9(4):224-33.

303(15):1498-506. profound hearing loss. J Speech Lang Hear Res. 2007 Aug; 50(4):1048-62. www.primarycarereports.co.uk | 15

SPECIAL REPORT:THE CLINICAL EFFECTIVENESS OF COCHLEAR IMPLANTS

Anderson I, et al. Cochlear implantation in children under the age of two--what do the outcomes show us? Int J Pediatr Otorhinolaryngol. 2004 Apr; 68(4):425-31.

Clark JH, et al. Cochlear implant rehabilitation in older adults: literature review and proposal of a conceptual framework. J Am Geriatr Soc. 2012 Oct;60(10):1936-45

UK Cochlear Implant Study Group. Criteria of candidacy for unilateral cochlear implantation in postlingually deafened adults. III: Prospective evaluation of an actuarial approach to defining a criterion. Ear Hear 2004;25:361–74.

Mawman DJ, et al. Trends and outcomes in the Manchester adult cochlear implant series. Clin Otolaryngol 2004;29:331–9.

S. Berrettini, et al. Systematic review of the literature on the clinical effectiveness of the cochlear implant procedure in adult patients. Acta Otorhinolaryngol Ital. 2011 October; 31(5): 299–310.

UK Cochlear Implant Study Group. Criteria of candidacy for unilateral cochlear implantation in postlingually deafened adults. I: Theory and measures of effectiveness. Ear Hear 2004;25:310–35.

M Bond, et al The effectiveness and cost-effectiveness of cochlear implants for severe to profound deafness in children and adults: a systematic review and economic model. Health Technology Assessment 2009; Vol. 13: No. 44

38 Caposecco A, Hickson L, Pedley K. Cochlear implant outcomes in adults and adolescents with early-onset hearing loss. Ear Hear. 2012 Mar-Apr;33(2):209-20. 39

Firszt JB,et al. Cochlear implantation in adults with asymmetric hearing loss. Ear Hear. 2012 Jul-Aug;33(4):521-33.

UK Cochlear Implant Study Group, authors. Criteria of candidacy for unilateral cochlear implant in postlingually deafened adults II: cost-effectiveness analysis. Ear Hear. 2004;25:336–360.

Friedland DR, et al. Case-control Analysis of cochlear implant performance in elderly patients. Arch Otolaryngol Head Neck Surg. 2010;136:432–438.

Chatelin V, et al. Cochlear implants outcomes in the elderly. Otol Neurotol.2004;25:298–301.

Poissant SF, et al. Impact of cochlear implantation on speech understanding, depression, and loneliness in the elderly. J Otolaryngol Head Neck Surg. 2008;37:488–494.

Orabi AA, et al. Cochlear implant outcomes and QoL in the elderly: Manchester experience over 13 years. Clin Otolaryngol. 2006;31:116–122.

Williamson RA, et al. Auditory performance after cochlear implantation in late septuagenarians and octogenarians. Otol Neurotol. 2009;30:916–920.

Noble W, al. Younger and older age adults with unilateral and bilateral cochlear implants: speech and spatial hearing self-ratings and performance. Otol Neurotol.2009;30:921–929.

Chan V, Tong M, Yue V, et al. Performance of older adult cochlear implant users in hong kong.Ear Hear. 2007;28:52S–55S.

Firszt JB et al. Restoring hearing symmetry with two cochlear implants or one cochlear implant and a contralateral hearing aid. J Rehabil Res Dev. 2008;45(5):749-67.

Ching TY et al. Binaural benefits for adults who use hearing aids and cochlear implants in opposite ears. Ear Hear. 2004 Feb;25(1):9-21. Peters BR, Litovsky R, Parkinson A, Lake J. Importance of age and postimplantation experience on speech perception measures in children with sequential bilateral cochlear implants. Otol Neurotol. 2007;29:649–57.

Litovsky RY, et al. Bilateral cochlear implants in children: localization acuity measured with minimum audible angle. Ear Hear. 2006;27:43–59.

Litovsky RY, Johnstone PM, Godar SP. Benefits of bilateral cochlear implants and/or hearing aids in children. Int J Audiol 2006;45(Suppl. 1):S78–91.

Margaret Tait et al. Bilateral versus unilateral implantation in young children published in International Journal of Pediatric Otorhinolaryngology 74 (2010) 206–211

Lovett RE et al. Bilateral or unilateral cochlear implantation for deaf children: an observational study. Arch Dis Child. 2010 Feb;95(2):107-12.

Summerfield AQ, et al. Self-reported benefits from successive bilateral cochlear implantation in post-lingually deafened adults: randomized controlled trial. Int J Audiol 2006;45(Suppl. 1):S99–107.

Verschuur CA, et al. Auditory localization abilities in bilateral cochlear implant recipients. Otol Neurotol 2005;26:965–71.

Litovsky R, et al. Simultaneous bilateral cochlear implantation in adults: a multicenter clinical study. Ear Hear 2006;27:714–31.

Laszig R, et al. Benefits of bilateral electrical stimulation with the nucleus cochlear implant in adults: 6-month postoperative. Otol Neurotol 2004;25:958–68.

Helbig S et al. Hearing Preservation after Cochlear Re-implantation. Otol Neurotol. 2012 Nov 29.

Dorman MF, et al. Localization and Speech Understanding by a Patient with Bilateral Cochlear Implants and Bilateral Hearing Preservation. Ear Hear. 2012 Nov 21.

Mowry SE, et al. New frontiers in cochlear implantation: acoustic plus electric hearing, hearing preservation, and more. Otolaryngol Clin North Am. 2012 Feb;45(1):187-203.

RNID. Sequential Bilateral Cochlear Implants in Teenagers – the User Experience. Funded by RNID available at: http://earfoundation.org.uk/downloads/microsoft_word_-_final_report.pdf

Sparreboom M et al. The effectiveness of bilateral cochlear implants for severe-to-profound deafness in children: a systematic review. Otol Neurotol. 2010 Sep;31(7):1062-71.

Appendix B: proposal paper presented to the Institute’s Guidance Executive. 18 May 2011. Available: http://www.nice.org.uk/nicemedia/live/12122/54458/54458.pdf

Wanna GB, Noble JH, et al. Assessment of Electrode Placement and Audiological Outcomes in Bilateral Cochlear Implantation. Otol Neurotol. 2011 Jan 28.

Chang SA, et al. Performance over time on adults with simultaneous bilateral cochlear implants. J Am Acad Audiol. 2010 Jan;21(1):35-43

Peters BR, Wyss J, Manrique M. Worldwide trends in bilateral cochlear implantation. Laryngoscope. 2010 May;120 Suppl 2:S17-44.

Basura GJ, Eapen R, Buchman CA. Bilateral cochlear implantation: current concepts, indications, and results. Laryngoscope. 2009 Dec;119(12):2395-401

69 70

Dunn CC, et al. Bilateral and unilateral cochlear implant users compared on speech perception in noise. Ear Hear. 2010 Apr;31(2):296-8 Laske RD, et al. Subjective and objective results after bilateral cochlear implantation in adults. Otol Neurotol. 2009 Apr;30(3):313-8.

16 | www.primarycarereports.co.uk

Primary Care Reports The leading specialist online research and networking resource for General Practitioners and other senior primary care professionals.

• U p to the minute news and other content available to all site users on a free-of-charge, open access basis. • Q ualified signed up members are able to access premium content Special Reports and interact with their peers using a variety of advanced online networking tools. • D esigned to help users identify new solutions, understand the implications of different choices and select the best options available. • T hought Leadership – Advice and guidance from internationally recognised primary care key opinion leaders. • Peer Input – Contributions from senior primary care professionals. • I ndependent Editorial Content – Expert and authoritative analysis from award winning journalists and leading industry commentators. • Unbiased Supplier Provided Content. • Designed to facilitate debate. • Written to the highest professional standards.

Visit: www.primarycarereports.co.uk