The relationship between changes in self-rated quality of life after cochlear implantation and changes in individual complaints

The relationship between changes in self-rated quality oflife after cochlear implantation and changes in individualcomplaints

Zhao, F.,* Bai, Z.†1 & Stephens, D.‡

*Centre for Hearing and Balance Studies, University of Bristol, Bristol, �Welsh Hearing Institute, University

Hospital of Wales, Cardiff, and �College of Medicine, Cardiff University, Cardiff, UK

Accepted for publication 5 June 2008

Clin. Otolaryngol. 2008, 33, 427–434

Objectives: To evaluate the changes in self-rated quality

of life (QoL) obtained following cochlear implantation in

relation to changes in the individual’s complaints.

Design: We have used repeated responses over a period

of at least 4 years following implantation so as to exam-

ine within-subject relationships.

Participants: Twenty-four consecutive post-lingually

deafened patients who had been fitted with

cochlear implants between 1991 and December

2000 at the University Hospital of Wales were

investigated.

Main outcome measures: The open-ended problems

questionnaire was used to assess what hearing impaired

people themselves considered to be the main problems

arising from their hearing loss. The participants were

asked to rate the severity of each one of these problems

as well as QoL on ‘0’ to ‘100’ visual analogue scales. Both

the individual problem ratings and the ratings of QoL

were re-administered to the subjects at each follow-up

session.

Results: Changes in the rated QoL of all patients were

significantly associated with changes in specific com-

plaints, for example, the ability to communicate, feeling

of isolation, telephone use, self-confidence, enjoyment of

music and watching the TV. Multiple stepwise regression

analysis showed that, after implantation, improvements in

communication abilities, reduced psychological problems

and improvements in abilities of daily life were the key

determinants of QoL improvement for individual

cochlear implant patients. These key predictors reached a -

plateau at about 1.5–3 years after cochlear implantation.

Conclusions: The relationships between changes in

specific complaints and the QoL in individual implantees

were highlighted. We suggest that cochlear implant

outcome measures should continue for at least 3 years after

implantation.

Since the development of cochlear implants (CI), there

has been considerable interest in their efficacy. Extensive

evaluations and assessments have been carried out on

profoundly deafened implanted patients to determine

how well they are able to perform using implants. Assess-

ments have included psychoacoustical tests, speech recog-

nition, speech production, music appreciation and

psychological changes.1–6 Most results show that CIs con-

stitute a successful and effective treatment for people with

severe and profound hearing impairment in terms of

providing improved audiological performance. However,

these results are often obtained in clinical or test situa-

tions and do not represent the ease or difficulty an indi-

vidual has in daily living. It is a well-known fact that

patients with identical audiometric characteristics may

have very different problems in daily life.7 Ultimately, the

aim of cochlear implantation is to minimise any disabili-

ties which an individual experiences as a result of pro-

found hearing loss, together with improving their quality

of life. Therefore, it is essential to evaluate the changes in

the specific activity limitations, participation restrictions

and quality of life (QoL) as perceived by CI patients so as

to define the effectiveness of the CI.

Following the current International Classification of

Functioning, Disability and Health (WHO ICF) formula-

tion,8 the concept of hearing impairment is defined as the

dysfunction measurable in the laboratory or in the clinic,

activity limitation being the auditory difficulties experi-

enced by the individuals (what they cannot do) and

Correspondence: Dr Fei Zhao, Centre for Hearing and Balance Studies,

University of Bristol, 5th Floor, 8 Woodland Road, Bristol BS8 1TN,

UK. Tel.: +44 117 928 7790; fax: +44 117 954 6809; e-mail:

[email protected] address: ENT ⁄ Head and Neck Surgery Department, Second

Affiliated Hospital of Kun Ming Medical College, Kun Ming, Yun Nan,

China

OR

IG

IN

AL

AR

TI

CL

E

� 2008 The Authors

Journal compilation � 2008 Blackwell Publishing Ltd • Clinical Otolaryngology 33, 427–434 427

participation restriction, the non-auditory effects of these

on their life (what they do not do). In addition, according

to WHO QoL working group, ‘Quality of Life (QoL) is

defined as an individual’s perception of their position in

life in the context of the culture and value systems in which

they live and in relation to their goals, expectations, stan-

dards, and concerns’9 It is frequently referred to and used

in relation to health in general and to the effects of disease

in particular. The QoL is a multi-dimensional construct,

with contributions from several different aspects, or

‘domains’ of life. It is more than just a reflection of health

status (i.e. physical, psychological and social well-being)

because it incorporates other life experiences such as eco-

nomic, occupational and domestic ⁄ family domains. There-

fore, evaluation of QoL should include different aspects of

the person’s physical health, psychological status, level of

independence and social relationships.

There have been many studies attempting to assess the

QoL changes in patients after cochlear implantation (e.g.

10–14) using questionnaires, which may comprise qualita-

tive and quantitative assessments. These studies have

shown that cochlear implantation leads to substantial

improvement in QoL. For example, the study by Mo

et al.,10 used the generic QoL measure SF36, the PQLF

(Patient Quality of Life Form) and the IRQF (Index Rela-

tive Questionnaire Form). Their results showed that CIs

were associated with significant improvement in QoL in

post-lingually deafened adults measured by the PQLF and

the IRQF. The improvement was mainly in the compo-

nents of communication, feelings of being a burden, iso-

lation and relationships with friends and family. There

was also a significant reduction in depression and anxiety.

Nevertheless, the SF-36 showed significant improvement

only in the scale of ‘general health’ but not in the other

seven scales, which indicated that the generic QoL mea-

sure SF-36 may not be suitable to detect change in QoL

in CI patients.

However, among the generic health-related QoL

(HRQol) measures, the HUI3 (Health Utilities Index

Mark 3) is recognised as one of the most effective tools

in measuring HRQoL improvements among CI recipients

because it contains a question related to hearing abil-

ity.11,12 This generic instrument is responsive not only to

diverse states of ill health and to intervention for them

but also to effects of profound deafness and of cochlear

implantation. It focuses on a person’s ability to undertake

certain tasks, such as hearing and speech production. In a

recent study by UK Cochlear Implant Study Group,13 it

was reported that adult implantees display significant

improvements on the hearing and speech attributes

measured by HUI3 9 months after the implantation. In

addition, long term benefits of CI were evaluated using

HUI3. The results were significantly better than those

obtained before CI in three domains (i.e. hearing, emo-

tions and the total utility score).

More recently, disease-specific HRQoL measures have

received increasing attention. For example, the Nijmegen

Cochlear Implant Questionnaire (NCIQ) was developed

by Hinderink et al.,14 and is a quantifiable, self-assess-

ment HRQoL instrument for use with CI users. Previous

studies have proved that NCIQ is reliable and valid and

sensitive to clinical changes. Moreover, the data obtained

from the NCIQ indicated that a CI had significant effects

on several aspects of HRQoL, including the social and

psychological domains.

In the present study, we have used patient-generated

methods to measure specific activity limitations, partici-

pation restrictions and the QoL in patients who had

received CIs in an attempt to define how changes in spe-

cific complaints influence the self-reported QoL in indi-

vidual implantees. In addition, we have used repeated

responses over a period of at least 4 years following

implantation so as to examine within-subject relation-

ships. The significant outcomes obtained from such an

analysis should provide further insight into the relation-

ship between QoL changes and improvements in specific

difficulties arising from the hearing impairment.

Materials and methods

Participants

Twenty-four consecutive postlingually deafened patients

who had been fitted with CIs between 1991 and Decem-

ber 2000 at the University Hospital of Wales comprised

the study population, and thus all patients had at least

4 years experience with their CIs by December 2004.

There were seven men and 17 women aged between 32

and 78 years (mean: 53.9 years, sd: 12.9 years). All partic-

ipants received information about the study and con-

sented to participate in the research.

The CIs fitted in this group of patients included: 16

Medel C40+, 3 Medel PRO+, 3 Nucleus 3G and 2

Nucleus Esprit22. Of those, six patients had received CIs

with the four-channel Ineraid initially, but four of these

had been upgraded to the Medel C40+, and two to Medel

PRO+ implants. Their median number of years of CI use

was 8.0 years. English was the first language of all the

patients. All were in good general health.

Procedures

For each patient with a CI, a clinical and audiometric

assessment was performed. The clinical history was

428 F. Zhao et al.


Journal compilation � 2008 Blackwell Publishing Ltd • Clinical Otolaryngology 33, 427–434

obtained at initial interview by an Audiological Physician

(one of the authors), including duration of hearing loss,

onset, history of tinnitus or vertigo and family history. The

aetiological investigation was based on medical history,

family history and clinical assessment, which included psy-

choacoustic tests and high resolution CT scans.

The external earhook and speech processor were fitted

6 weeks postoperatively. All received at least 3 months

intensive therapy carried out by the same Hearing Thera-

pist at the Welsh Hearing Institute, Cardiff. The patients

received approximately 50 hours of communication train-

ing in the first 9 months.

All CI patients had pre-CI assessment as well as a

number of follow-ups over a 9, 12, 18, 24, 36 and 48-

month periods of use of their CIs, followed by annual

intervals, extending up to 14 years. In the present study,

data obtained from the first six follow-ups were analysed.

The mean times post-implantation of the first six follow-

ups were 6.9, 12.7, 18.4, 24.9, 38.7 and 50.7 months.

Questionnaires

Each patient seen for consideration for a CI was sent

the open-ended problems questionnaire15 with their

appointment and asked to list any and all difficulties

they experienced as a result of their hearing loss. The

wording was as follows: ‘Please make a list of the diffi-

culties which you have as a result of your hearing loss.

List them in order of importance to you, starting with

the biggest difficulties. Write down as many as you can

think of’. In most cases the difficulties listed were expli-

cit [e.g. ‘hearing my wife when the television is on’, but

in some they were extremely general (e.g. ‘people speak-

ing’)]. In such cases, during the clinical interview, the

patient was asked to clarify the statement and ⁄ or be

more concise.

Next, the patients were asked to rate the severity of

each one of these problems on a ‘0’ to ‘100’ visual ana-

logue scales using the approach described by Habib and

Hinchcliffe.16 For example:

Hearing has no effect on confidence Complete loss of

Complaint: Loss of

0 100

Cochlear implant patients were reminded of their spe-

cific complaints when they attended follow-up sessions.

Their specific problems were repeated to patients on each

occasion so that the patients were able to rate the severity

of each initial individual complaint on the same scale.

Self-rated quality of life

The patients were asked to quantify their QoL on a simi-

lar scale. The following wording was used:

‘Please rate the effect of your hearing loss on the over-

all quality or enjoyment of life. If it has no effect the

score would be 0, if it completely ruined your life it

would be 100’.

Both the individual problem ratings and the ratings of

QoL were re-administered to the subjects at each follow-

up session, without the individual being informed of their

previous ratings.

Ethical considerations

All participants were provided written information before

joining in this study. They agreed to participate in the

study on a voluntary basis, and understood that they

could withdraw from this study at any time without

affecting their treatment. We obtained ethical approval

from the R&D Research Committee of the Cardiff and

Vale NHS trust.

Results

Specific problems reported by participants

All participants were asked to list the hearing difficulties

which they had as a result of their hearing loss. Table 1

shows all problems which were specified by this group of

the participants. It is noteworthy that ‘communication dif-

ficulties’ (18 ⁄ 24, 75.0%) and ‘feeling of isolation’ (17 ⁄ 24,

70.8%) were the most common complaints. Other com-

mon complaints were ‘difficulties in using telephone’, ‘loss

of confidence’, ‘difficulties in enjoying music’, ‘effect on

social life’ and ‘difficulties in watching TV’. Furthermore,

there were several other specific complaints which less

common, for example, ‘can’t hear alarms or voice’, ‘tinni-

tus’, ‘hearing speech in the presence of background noise’,

‘effect on career’, ‘worry about traffic’, ‘feeling of discrimi-

nation’, ‘tiredness’, ‘feeling of depression’, ‘feeling of bore-

dom’ and ‘need concentration’.

The magnitudes of QoL and the common complaints,

together with their changes post-implantation

The magnitude of the mean changes over time for QoL

and the common problems are shown in Fig. 1. In gen-

eral, the changes over time for QoL were consistent with

the changes across all complaints. Figure 2a shows such

an example of the subject’s responses in which there was

a consistent change across all complaints. However, the

Predictors of quality of life post-implantation 429



changes for various complaints in some other subjects

differed from each other, as shown in Fig. 2b. It is obvi-

ous that there will be stronger relationships between rated

QoL and the individual complaints in a subject whose

responses all show the same pattern than in cases in

which there are more disparate responses.

Relationship between changes in self-rated QoL and

changes in their specific complaints across the different

follow-up sessions

The relationships between changes in rated QoL and in

their specific complaints across the different follow-up

Table 1. Summary of complaints specified by 24 individual cochlear implant patients and their significant correlations between

changes in self-rated quality of life and specific measures

Complaint list

Number reporting

as a problem

(out of 24 subjects)

Numbers of subjects

showing significant

correlations between

changes in QoL and

complaint

Numbers of subjects

showing complaint as

a determinant by multiple

stepwise regression

Effect on communication 18 15 9

Feeling of isolation 17 15 6

Difficulties using the telephone 13 10 4

Loss of confidence 13 10 3

Effect on enjoyment of music 12 11 3

Effect on social life 10 5 0

Effect on watching TV 9 7 4

Cannot hear alarms or voice 7 1 0

Tinnitus 6 3 1

Speech in noise 6 3 0

Effect on career 6 1 0

Worry about traffic 5 2 0

Feeling of discrimination 3 1 0

Tiredness 3 2 0

Need to concentrate 3 1 0

Feeling of depression 3 2 0

Feeling of boredom 3 1 0

Effect on relationship with son 1 1 0

No independence 1 0 0

QoL, quality of life.

60

70

80

90

100QoL

Communication

Feeling of isolation

Using phone

Loss of confidence

0

10

20

30

40

50

60

Pre-CI 6 months 12 months 18 months 24 months 36 months 48 months

Mea

n r

atin

g

Pre and post implantation

Enjoyment of music

Social life

Wathcing the TV

Fig. 1. The magnitude of the mean

changes over time for QoL and the com-

mon problems reported by cochlear

implant patients.

430 F. Zhao et al.



sessions for each participant were analysed with

Kendall’s tau correlation coefficients. The results for each

complaint are shown in Table 1. Post-implantation,

changes in QoL for all patients were significantly associ-

ated with changes in one or more specific complaints.

Of those, 15 out of 18 subjects’ improvements in QoL

was significantly correlated with improved communica-

tion. In 15 of 17 individuals improvements in QoL were

significantly associated with reduced feeling of isolation

and in 10 of 13 with improved using the telephone and

self-confidence, in 11 of 12 it was significantly related to

improved enjoyment of music. Furthermore, in five of

10 participants it was significantly associated with

improvements in social life and also in six of nine par-

ticipants with improved watching the TV; in three of six

participants QoL changes were significantly associated

with reductions in tinnitus.

Further multiple stepwise regression analysis showed

that, after implantation, different variables appeared to be

the key determinants for QoL improvement in different

patients with CIs. After implantation, improved commu-

nication in nine subjects (9 ⁄ 18, 50.0%) became the key

determinant of improvements in QoL. In addition,

reduced ‘feeling of isolation’ (6 ⁄ 17, 35.3%), improved use

of the telephone (4 ⁄ 13, 30.8%), enjoyment of music

(3 ⁄ 12, 25.0%), watching the TV (4 ⁄ 9, 44.4%), together

with increased self confidence (3 ⁄ 13, 23.1%) were also

key determinants of improvements in QoL.

The times, post-implantation, at which each complaint

reached a plateau for different individuals

The rating of each common complaint for each individ-

ual was analysed to determine when it reached a steady

60

70

80

90

100QoL

Communication


Using phone

Enjoyment of music

0

10

20

30

40

50Loss of confidence

Social life

100QoL

80

90 Communication


60

70 Worry about traffic

Enjoyment of music

Tinnitus

40

50Watching the TV

20

30

0

10

Ind

ivid

ual

rat

ing

Ind

ivid

ual

rat

ing





(a)

(b)

Fig. 2. (a, b) Examples of the relation-

ships between the changes of self-rated

quality of life and the changes of individ-

ual complaints in two individuals.




state or plateau in terms of the different follow-ups after

implantation. These results are shown in Fig. 3. Most

individuals’ improvements in psychological problems (for

example, feeling of isolation and loss of confidence)

reached a plateau at the third to fourth follow-ups after

implantation (i.e. 1.5–2 years). The improvements in abil-

ities of daily life (such as using the telephone, enjoyment

of music, watching TV and social life) appeared to take

longer to reach a steady status. None or a few of these

problems reached a plateau within the first two follow-

ups after implantation. Most individuals’ improvements

in abilities of daily life reached a plateau at the third to

fifth follow-ups after implantation (i.e. 1.5–3 years). Over

80% of participants reported that improvements in their

tinnitus reached to a steady status within the first three

follow-ups after implantation. By contrast, the problem

with ‘effect on career’ took much longer than other prob-

lems to improve to a steady-state level.

Discussion

The effectiveness of cochlear implantation has been evalu-

ated in numerous studies.1–6 The studies have demon-

strated that CIs provide not only audiological benefits in

terms of sound awareness and improved speech percep-

tion, but also reduce the activity limitation and participa-

tion restriction, for example, improvement in general

communication and self-confidence, and consequently

improve the QoL. Mo et al.10 reported that duration of

deafness and audiological benefit did not show a signifi-

cant association with change in QoL, but found a signifi-

cant association between reduction in depression and

anxiety and improvement in QoL. Moreover, in the study

by Hallberg, the variance in psychological general well-

being can be partially explained by attitudes from others,

restricted social participation, perceived social support

and age.17

40

50

60

40

50

60

40

50

60 Communication Feeling of isolation Loss of confidence

0

10

20

30

0

10

20

30

10

20

30

40

50

60

40

50

60

40

50

60 Social life Using phone Enjoyment of music

10

20

30

10

20

30

10

20

30

40

0 0

50

60

50

60 Watching TV

0

50

60 Effect on careers Tinnitus

20

30

40

20

30

40

20

30

40

Th

e p

erce

nta

ge

of

coch

lear

imp

lan

t p

atie

nts

rea

chin

g a

ste

ady

stag

e le

vel

Different follow-ups stages after implantation

0

10

0

10

0

10

Months Months Months



Fig. 3. The percentage of cochlear implant patients reaching a steady state level for each complaint in terms of the different follow-

ups after implantation.

432 F. Zhao et al.



Although many structured questionnaires are available

to evaluate activity limitation and participation restriction

caused by hearing impairment, most of the scales are usu-

ally designed for the general hearing impaired population.

These often contain questions that are irrelevant to the

profoundly deafened. They may experience extremely var-

iable hearing difficulties and benefits from an implant.

An open-ended questionnaire approach used in this study

has been found to be a useful tool in highlighting specific

difficulties encountered by patients with hearing impair-

ment. It has also been used to assess the advantages and

disadvantages in patients after using CIs.18,19 Such a tech-

nique allows the patients to describe their important diffi-

culties in a more realistic and specific way than when

using structured questionnaires. There is evidence show-

ing that open-ended hearing problem questionnaires can

be worded to highlight the specific hearing activity limita-

tions and participation restrictions encountered by

patients with hearing difficulties.20,21 Moreover, the

impact of hearing impairment on QoL can also be exam-

ined by this technique.22 Compared with structured ques-

tionnaires, open-ended questionnaire tends to generate

large amounts of data that can take a long time to pro-

cess and analyse, using qualitative techniques.

Furthermore, Self-rating measures have become increas-

ingly popular and are expanding in audiological and

related research and practice in the assessment of hearing

aids benefits, communication strategy, and the effectiveness

of CIs.23 In the present study, the new technique modified

by combination of self-rating measure and the open-ended

questionnaire offers a useful and relevant tool in not only

highlighting the specific complaints of CI patients, but also

reflecting the quantitative changes in them.

Thus in the 24 profoundly deafened adults, whose CI

experiences were more than 4 years and who were asked

to report their difficulties using the open-ended hearing

problem questionnaire, the most commonly reported

hearing difficulties problems were with communication,

feeling of isolation, using the telephone, enjoyment of

music, watching TV, loss of confidence and loss of social

life. These common complaints come in both the ‘live

speech’ and ‘psychosocial’ domains. This clearly provides

the valuable insights for understanding activity limitation

and participation restriction in CI patients.

Furthermore, the improvement in the QoL in pro-

foundly deafened adults after they had received CI and its

relationships toward changes in individual complaints

were also investigated in this study. Overall, the changes

over time for QoL were consistent with the changes

across all complaints. However, the changes in some

complaints did not follow the same patterns of the

changes for QoL. This result may imply the variety of the

effectiveness of CI in meeting the patients’ specific needs.

In addition, it also indicates that some less important

complaints are not significantly associated with improved

QoL.

Further correlational analyses showed that changes in

QoL for all patients were significantly associated with

changes in specific complaints. Moreover, multiple step-

wise regression analysis indicated that improvements in

communication abilities, psychological problems (for

example, feeling of isolation and loss of confidence) and

abilities of daily life (such as using the telephone, enjoy-

ment of music, watching the TV) are the key determi-

nants of QoL improvement for individual CI patients.

Improvement in some CI recipients was often a gradual

process. Previous studies have shown that improvements

in psychological state after cochlear implantation have

occurred from 12 to 36 months after surgery.24 Tyler

et al.25 found that most gains in performance occur in

the first 9–12 months of use of the CIs, but many

patients continue to improve over the first one-and-a-half

to two-and-a-half years, and even longer. In our study,

we found that improvements in specific complaints for

most individuals had reached a steady state at third to

fifth follow-ups after implantation (i.e. 1.5–3 years). For

example, most individuals’ improvements in psychologi-

cal problems reached a plateau at third to fourth follow-

ups (i.e. 1.5–2 years), and improvements in abilities of

daily life reached a plateau at third to fifth follow-ups

after implantation (i.e. 1.5–3 years). However, our results

showed that the problem with ‘effect on career’

needs much longer than other problems to improve to a

steady-state level. We therefore suggest that CI

outcome measures should continue at least 3 years after

surgery.

Acknowledgements

The work was performed when Zhong Bai was a visiting

scholar researching in Welsh Hearing Institute. Dr Bai

was supported by China Scholarship Council (CSC). We

would like to thank the Cardiff Cochlear Implant Team

for their help throughout the study.

Conflict of interest

None to declare.

References

1 Tye-Murray N., Tyler R.S., Woodworth G.G. et al. (1992) Per-

formance over time with a nucleus or ineraid cochlear implant.

Ear Hear. 13, 200–209




2 Hinderink J., Mens L.H.M., Bronx J.P.L. et al. (1995) Perfor-

mance of prelingually and postlingually deaf patients using sin-

gle-channel or multi-channel cochlear implants. Laryngoscope

105, 619–622

3 Parkinson A.J., Parkinson W.S., Tyler R.S. et al. (1998)

Speech perception performance in experienced cochlear-

implant patients receiving the SPEAK processing strategy in

the Nucleus Spectra-22 cochlear implant. J. Speech Lang. Hear

Res. 41, 1073–1087

4 Labadie R.F., Carrasco V.N., Gilmer C.H. et al. (2000) Cochlear

implant performance in senior citizens. Otolaryngol. Head Neck

Surg. 123, 419–423

5 Djalilian H.R., King T.A., Smith S.L. et al. (2002) Cochlear

implantation in the elderly: results and quality-of-life assess-

ment. Ann. Otol. Rhinol. Laryngol. 111, 890–895

6 Dorman M.F., Basham K., McCandless G. et al. (1991) Speech

understanding and music appreciation with the Ineriad cochlear

implant. Hearing J. 44, 34–35

7 Bai Z. & Stephens S.D.G. (2005) Subjective outcome measures

after cochlear implantation: overall measures. Audiological Med.

3, 212–219

8 Stephens S.D.G. & Hetu R. (1992) Impairment, disability and

handicap in audiology: toward a consensus. Audiology 30, 185–

200

9 WHO QOL Group. (1993) Measuring Quality of Life: The Devel-

opment of the World Health Organization Quality of Life Instru-

ment (WHO QOL). WHO, Geneva

10 Mo B., Lindbaek M. & Harris S. (2005) Cochlear implants and

quality of life: a prospective study. Ear Hear. 26, 186–194

11 Abrams H.B., Chisolm T.H. & McArdle R. (2005) Health-related

quality of life and hearing aids: a tutorial. Trends Amplif. 9, 99–

109

12 Damen G.W., Beynon A.J., Krabbe P.F. et al. (2007) Cochlear

implantation and quality of life in postlingually deaf adults:

long-term follow-up. Otolaryngol. Head Neck Surg. 136, 597–604

13 UK Cochlear Implant Study Group. (2004) Criteria of candidacy

for unilateral cochlear implantation in postlingually deafened

adults I: theory and measures of effectiveness. Ear Hear. 25,

310–335

14 Hinderink J.B., Krabbe P.F. & Van Den Broek P. (2000) Develop-

ment and application of a health-related quality-of-life instrument

for adults with cochlear implants: the Nijmegen cochlear implant

questionnaire. Otolaryngol. Head Neck Surg. 123, 756–765

15 Barcham L.J. & Stephens S.D.G. (1980) The use of an open-

ended problems questionnaire in auditory rehabilitation. Br. J.

Audiol. 14, 49–54

16 Habib R.G. & Hinchcliffe R. (1978) Subjective magnitude of

auditory impairment. Audiology 17, 68–76

17 Hallberg L.R.M.A., Ringdahl A. & Holmes C.C. (2005) Psycho-

logical general well-being (quality of life) in patients with cochl-

ear implants: importance of social environment and age. Int. J.

Audiol. 44, 706–711

18 Zhao F., Stephens S.D.G., Sim S.W. et al. (1997) The use of

qualitative questionnaires in cochlear implant candidates. Clin.

Otolaryngol. 22, 254–259

19 Tyler R.S. (1994) Advantages and disadvantages expected and

reported by cochlear implant patients. Am. J. Otol. 15, 523–531

20 Zhao F. & Stephens S.D.G. (1996) Hearing complaints of patients

with King-Kopetzky Syndrome. Br. J. Audiol. 30, 397–402

21 Lormore K.A. & Stephens S.D.G. (1994) Use of the open-ended

questionnaire with patients and their significant others. Br. J.

Audiol. 28, 81–89

22 Maillet C.J., Tyler R.S. & Jordan H.N. (1995) Change in the

quality of life of adult cochlear implant patients. Ann. Otol. Rhi-

nol. Laryngol. Suppl. 165, 31–48

23 Cox R., ed. (2000) Proceedings of the workshop ‘Self-reported

outcome measures in audiological rehabilitation including hear-

ing aids’. Ear Hear. 21, S1–S115

24 Knutson J.F., Murray K.T., Husarek S. et al. (1998) Psychologi-

cal change over 54 months of cochlear implant use. Ear Hear.

19, 191–201

25 Tyler R.S., Parkinson A.J., Woodworth G.G. et al. (2007) Perfor-

mance over time of adult patients using Ineraid or Nucleus

cochlear implant. J. Acoust. Soc. Am. 102, 508–522

434 F. Zhao et al.



Documents

The relationship between changes in self-rated quality of life after cochlear implantation and changes in individual complaints