Authors' objectives:

To review the clinical indications of cochlear implants (CI) for children and adults, as well as determining its efficacy and safety.

Authors' results and conclusions: POSTLINGUAL PATIENTS According to the review carried out by the Agencia de Evaluaci n de Tecnolog as Sanitarias (AETS) in 2003, the results in this group of patients (children and adults) are highly satisfactory. In all the word-choice tests in closed and open series, a fast and favourable evolution was observed in the first six months post-implantation, with statistically significant differences with regard to the initial situation. This trend is maintained over time and stabilises two years after the placement of the CI. The implants are capable of understanding an average of 80% of words in an open environment without any type of visual aid and can use the phone in approximately 60% of the cases. The postlingual patients (children and adults) are able to recognise a great number of environmental sounds, control use of the voice, improve understanding of the spoken word and even maintain an interactive conversation without lip-reading. This makes these patients feel more confident and independent, improving their integration in the family, social and school/work environment. This improvement in quality of life is also corroborated by the results described in one of the reviews identified after the assessment reports of the Spanish Agencies and in the Survey 500 of the Association of Cochlear Implants of Spain (on a sample of 500 implants). In adults, the only assessment report identified from a foreign agency indicates that all the studies assessed (5 small-sample non-randomised studies) report on improvements in hearing or in implants' health-related quality of life in comparison with controls (patients on the waiting list for one CI or in hearing-aid users). PRELINGUAL PATIENTS On the basis of the results described in the AETS assessment report, the experience accumulated shows that the intracochlear multichannel CI are biologically safe systems and suitable for application in the child population. In the specific group of 6 years or under, the studies indicate that they are capable of recognising the spoken word in an open environment without the visual aid of lip-reading or signs. They also suggest that children implanted earlier (<3 years) have a greater probability of attaining these skills and of developing their spoken language better. However, it is important to remember that once the critical hearing period has been overcome, there may be individual differences derived from medical factors and those pertaining to educational care and rehabilitation received by the child post-implantation, as well as environmental factors. In cases of deep bilateral hypoacusia and under the same schooling and rehabilitation conditions, the results achieved by child implants are significantly higher than those observed in children that use hearing-aids or vibrotactile devices. The main factors that may contribute to the success are: Duration of the hypoacusia: it is unanimously asserted that results are significantly better in individuals with less hearing deprival time, be they postlingual or prelingual hypoacusia. Moment of onset of the hypoacusia: more favourable results are to be expected in the postlingual deaf, since they have an auditive memory. Motivation: the active collaboration of the patient, the family and the social environment is essential to develop a suitable process of rehabilitation that will lead to best results. Other factors: prior use of hearing-aids, oral communication, good lip-reading, deeper electrode insertion, broader dynamic range to promontorial stimulation, are situations related to a good prognosis.

Authors' recommendations: The experience achieved with this technology (cochlear implant) shows favourable results in prelingual and postlingual patients, adults and children, better than those observed in users of hearing-aids or vibrotactile apparatuses, despite the known limitations of the CI which do not permit the same auditive understanding as a person with normal hearing. CI technology requires a highly specialised multidisciplinary team that takes care of the different phases of the CI programme in coordinated fashion (screening, surgery, scheduling and rehabilitation).

Authors' methods: Systematic review

Project Status: Completed

URL for project: http://www.gencat.net/salut/depsan/units/aatrm/html/en/dir393/doc7921.ht ml

Year Published: 2006

English language abstract: An English language summary is available

Publication Type: Not Assigned

Country: Spain

Organisation Name: Agencia de Qualitat i Avaluacio Sanitries de Catalunya

Contact Address: Antoni Parada, CAHTA, Roc Boronat, 81-95 (2nd floor), 08005 Barcelona, Spain, Tel. +34 935 513 928, Fax: +34 935 517 510

Contact Name: direccio@aatrm.catsalut.net / aparada@aatrm.catsalut.net

Contact Email: direccio@aatrm.catsalut.net / aparada@aatrm.catsalut.net

Copyright: Catalan Agency for Health Technology Assessment and Research (CAHTA)