Cochlear implants (CIs) provide useful hearing for those individuals who get little or no benefit from hearing aids and has been cost-effective (Bond et al., 2009; Raine et al., 2010). The candidacy for CIs has changed over time and people with better residual hearing are also potential candidates.

Hearing loss is associated with social isolation (Karpa et al., 2010) which impacts on the overall quality of life (Gopinath et al., 2009), increases the emotional handicap (Mulrow et al., 1990), and impairs activities of daily living (Gopinath et al., 2012). Hence, it is important to treat the hearing loss (HL) to improve both ‘functional and psychological contributions to quality of life’ (Francis et al., 2002). Speech perception gains post-cochlear implantation resulted in improved quality of life and social well-being in post-lingually hearing-impaired people. This suggests that the improved access to speech from a CI helps in achieving better sense of well-being, quality of life, and increase in confidence and social activity (Francis et al., 2002).

As of October 2012, Advanced Bionics (CA, USA) considers severe-to-profound HL of pure tone average (PTA) ≥70 dB (HL) in both ears and an aided sentence test score of ≤50% in the ear to be suitable for a CI (Advanced Bionics, 2012). Cochlear's (Melbourne, Australia) recommendations for cochlear implantation are moderate-to-profound HL bilaterally and speech perception aided score of ≤50% in the ear to be implanted and aided score of ≤60% in both ears (Cochlear, 2012). Medel (Innsbruck, Austria) considers adults who have severe-to-profound sensorineural HL bilaterally but do not give guidance on speech perception scores (Medel, 2012). All three manufacturers want to demonstrate that suitable candidates have no or little benefit from hearing aids.

There is no global consensus in relation to the CI candidacy with the US Food and Drug Administration indicating CIs for adults with their PTA ≥70 dB (United Healthcare Medical Policy, 2013). The Italian guidelines for CIs in adults include bilateral severe-to-profound HL with the average of 500 Hz, 1 and 2 kHz >75 dB HL (Berrettini et al., 2011). The Belgian guidelines allow cochlear implantation in adults with bilateral HL whose PTA thresholds are worse than 85 dB at 500 Hz, 1 and 2 kHz, and phoneme score of <30% using monosyllabic words (De Raeve and Wouters, 2013). These guidelines suggest that cochlear implantation is offered for adults even with better residual hearing. Pre-implant residual hearing is one of the important attributes contributing to the post-operative outcomes. There is an association between the residual hearing and post-implant speech perception outcomes (Friedland et al., 2003; Rubinstein et al., 1999) with better residual hearing indicative of better post-implantation performance.

The National Institute for Health and Care Excellence (NICE) recommend CIs for individuals whose pure-tone thresholds are worse than 90 dB (HL) at 2 and 4 kHz and who have an aided score of <50% on Bamford–Kowal–Bench (BKB) sentence testing (NICE, 2009). These are guidelines rather than a mandatory protocol.

In the UK, the commissioning groups rely on the NICE guidelines to make decisions on funding cochlear implantation and with the change in the economic situation, the commissioning groups are becoming more rigid and adhering to the guidelines as a strict criterion rather than considering the clinicians judgement in deciding the candidacy. The result is that adult patients, who could benefit from CIs at the earliest opportunity, have been refused funding for cochlear implantation without the patient's hearing handicap being taken into account.

This raises important questions: what about those patients who are not deriving enough benefit from hearing aids but do not satisfy NICE guidelines on audiometry? Are some individuals disadvantaged with only high-frequency HL being taken into account in the NICE guidelines? This leaves some individuals with undesirable outcomes, where there is a significant impact of the HL on their communication abilities, quality of life, social participation, and activities of daily living, but not CI candidates based on their audiogram. Does this mean these people being denied equality of opportunity to benefit from cochlear implantation at the earliest available opportunity?

The paper reports two patients whose audiograms were just outside the guidelines but the aided BKB speech test scores were within the NICE guidelines, and funding for cochlear implantation was refused.

Ethical considerations

Ethical approval was received from the University of Southampton Faculty of Engineering and the Environment Ethics Committee. The patients consented for their anonymous data to be used for research purposes, and also consented for this case study to be written.

Case 1

A 78-year-old female with a progressive severe-to-profound HL was referred to the University of Southampton Auditory Implant Service (UoSAIS). The patient is a consistent hearing aid user and manages to communicate with people on a 1:1 basis with lip-reading. The patient has a lot of difficulty understanding in groups, which prevents her from being able to socialize and she has to turn down many social invitations leading to social isolation. The patient no longer uses the telephone and relies on text messaging, E-mail, text relay service, and on subtitles to watch television.

The unaided pure-tone audiometry results were indicative of profound HL on left ear and severe-to-profound HL on right ear. The aided BKB score with well-fitted bilateral hearing aids was 19%.

Table 1 Unaided pure-tone audiogram

Table 1 Unaided pure-tone audiogram

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Table 2 Aided BKB sentence scores (% keywords)

Table 2 Aided BKB sentence scores (% keywords)

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Case 2

A 49-year-old female with congenital progressive HL was referred to the UoSAIS. The patient has worn bilateral hearing aids from the age of 5 and currently derives little benefit from the left hearing aid and some benefit from the right hearing aid. The patient relies on lip-reading and her residual hearing with powerful bilateral hearing aids to communicate. The patient struggles to have a conversation with more than two people or in any degree of background noise. There is a feeling of withdrawing into herself with her increasing deafness and she expressed frustration at the limitations her HL places on her social life. The patient finds processing auditory information very tiring as she is constantly ‘filling in the gaps’ in an effort to keep up with conversation. The patient relies on subtitles to watch television and on her dog to alert her to the doorbell.

The results indicate a profound HL on the left ear and severe-to-profound HL on the right ear and the bilateral aided BKB sentence score was 21% (Tables 1 and 2).

The results in both cases confirm that they clearly met the NICE TAG 166 criteria for inability to benefit from conventional hearing aids as they scored less than 50% correct on the BKB sentence test. However, both patients’ hearing at 4 kHz in the right ear is presently just outside the guidelines and this is the reason cited for funding being refused even after appealing the earlier decision. Of the two cases, one patient's hearing deteriorated further and the patient was implanted and the second patient had to be discharged. Even in the case of the patient being implanted, she was denied benefit from a CI at the earliest possible opportunity, thus increasing the length of auditory deprivation.

Audiological rehabilitation of the patients should place emphasis on the difficulties experienced rather than the level of HL reflected from a pure-tone audiogram (Stephens and Kramer, 2009). A pure-tone audiogram does not always reveal the problems faced by a patient with sensorineural HL (Manchaiah, 2011; Manchaiah and Freeman, 2011) and the audiogram does not reflect the limitations of the damaged cochlear epithelium in carrying the required information important for speech recognition without and with hearing aids (Halpin and Rauch, 2009). The basal part of the cochlea encodes low-frequency information, thus the high-frequency HL effects are not limited to high-frequency speech perception (Horwitz et al., 2002). Moreover, patients with similar audiogram configurations exhibit varying levels of communication difficulties (Erdman and Demorest, 1998). Thus, it becomes of utmost importance to consider individual patient's difficulties with communication, psychosocial, and employment domains rather than just the audiogram.

In addition, the test to retest reliability of pure-tone audiometry also needs to be considered. There is a 90% chance that the threshold can vary between −10 and +10 dB of the original threshold without an actual change in hearing for a single frequency using the same audiometer and the same procedure (Lemkens et al., 2002). Thus to exclude a patient from cochlear implantation on the basis that one of their pure-tone thresholds is 5–10 dB below the guideline is not scientifically evidence based.

Speech recognition gains were seen in most hearing impaired listeners when the low-frequency speech below 2500 Hz was amplified. On the contrary, amplifying speech when the HL is >80 dB in the high-frequency region showed no improvement in speech recognition and in some cases it lead to deterioration of speech recognition scores (Turner and Brus, 2001). This shows that hearing aids do not help in restoring normal speech recognition in all situations, and for those individuals who do not get enough benefit from amplified speech, cochlear implantation has been an effective option (Turner, 2006).

The audiogram does not give a clear picture of the impact of the HL on the social life of a patient and even with well-fitted hearing aids there could be challenges to speech perception. Cochlear implantation needs to be considered to provide increased access to speech, which increases confidence and ability to socialize. In patients with auditory neuropathy spectrum disorder (ANSD), the audiogram is not considered as main criteria for cochlear implantation rather the functional hearing with the hearing aids is considered and ANSD patients with no or little benefit from hearing aids are considered to be candidates for CIs. Similarly, individuals who are not deriving benefit from the hearing aids should be considered for cochlear implantation as there is no measure to quantify the damage done to the cochlea.

With the commissioning groups strictly adhering to the NICE guidelines, not considering the circumstances of the individual patient and clinical judgement, the authors propose a revised candidacy. In these two cases the average pure-tone thresholds were >90 dB HL bilaterally. In similar cases where the entire NICE guidelines do not apply, the average of the whole frequency range of pure-tone hearing threshold levels at 250 Hz, 500, 1000, 2000, and 4000 Hz >90 dB HL (British Society of Audiology procedure for audiometry, 2004), and BKB scores <50% need to be considered. The recommendation for a CI should be always based on functional hearing, taking into account the difficulties faced by the patients and their families in real-life situations rather than strictly adhering to the high frequency part of the audiogram.

Furthermore, the candidacy for cochlear implantation is variable across the globe with majority of the countries considering CIs even for individuals with more residual hearing. The situation demands asking some questions such as, is it time to reconsider the NICE guidelines? Do we need to still rely on audiogram thresholds? Do we need to consider hearing across the whole speech frequency range when the aided speech test scores indicate that a patient is struggling to hear with hearing aids? This paper reports only two patients but the authors feel there will be more clinicians/centres facing the same issue of not being able to provide better access to hearing at the earliest opportunity.