Health-related quality of life of Austrian children and adolescents with cochlear implants

Summary

Background and objective:

As shown by many studies, deaf children benefit considerably by cochlear implants (CI), concerning oral language and integration in mainstream schools. This had lead to the general view of a good quality of life of these children. Unfortunately so far nearly no studies on quality of life, and specially no studies on health-related quality of life (HRQoL) of children with cochlear implants, have been published. The present study with the objective for first, initial information on health-related quality of life of Austrian pupils with cochlear implants is a first step to fill this gap.

Methods:

Forty-four Austrian pupils, out of 65 candidates, age 8–16, with a hearing experience of at least 3 years with implants, and their parents were surveyed in the CI Center, Salzburg (cross sectional study). Basic medical and audiological data were available for all pupils. Because of reading comprehension difficulties 15 pupils were excluded. Parents and children were surveyed with the KINDLr, a generic instrument for health-related quality of life of children and adolescents. Main outcome measures were the HRQoL-total scores (mean, transformed to 100, standard deviation). In addition, 95% confidence intervals, effect sizes, t scores (one- and two-sided t-tests), rank order correlations and coefficients of determination were calculated.

Results:

The HRQoL-total score of the children with CI (n = 18), age 8–12 was below the standard for hearing children (P < 0.001). It differed from the total score of the parent rating (P < 0.0001). The difference between the parent ratings of non-excluded and of excluded children (n = 12) was not significant. The total score of the adolescents (n = 11), age 13–16 was within the norm, with no significant difference between adolescent and parents. The total scores correlate with parent–child agreement in the ratings, with outcomes of audiological speech tests, length of time of deafness, and age at implantation.

Conclusions:

Children with CI experience a lower health-related quality of life, compared to hearing children, with a low parent–child agreement. The findings of this study point to a normal subjective health of adolescents with CI.

Introduction

A number of studies have shown that children with profound hearing impairments benefit considerably from cochlear implants (CI). They have far better chances to learn oral language (e.g. [1], [2], [3], [4], [5]) and to be integrated in mainstream schools [6], which also implies better chances for a general integration in the hearing world.

So far only very few studies attempted to deal with more general objectives, concerning the life of this population (e.g. [7]), beyond hearing, speech, sort of school, and cost–utility analyses [8]. Literature is particularly limited for the topics “functional health status” and “health-related quality of life” of children and adolescents with cochlear implants. This is not only relevant for parents and clinics, but also for health policy.

Functional status provides insight into limitations of social roles or activity limitations from a subjective view [9]. Health-related quality of life (HRQoL), a medical definition of quality of life, refers to the subjective perceived health [10] (orientation to the definition of health of the WHO (1947)) or to the subjective well being of a person.¹ It is a multidimensional construct, including at least three aspects or dimensions: physical functioning, mental functioning, and social functioning. According to all approaches to health-related quality of life, the assessment of the individual concepts forming these dimensions can only be done by subjective measures. Evaluation means, asking the patient himself, or if the patient is unable to make a coherent response, asking a relative, friend, or close observer (proxy).

In case of children, widespread consensus exists that the child's self-report is the optimal strategy for assessing HRQoL, because its consistency with its definition (see, e.g. [12]). It is however important, that the instrument used for the assessment of HRQoL is based on a construct for pediatric population and that it is sensitive to cognitive development [12]. Furthermore, children have to be older than 7 years and must not be too ill to answer (in this case parent ratings are obviously necessary [9]). Therefore, very often self-ratings are combined with proxy ratings (mostly parents).

So far, only few studies are available on HRQol or on functional health status of children and adolescents with some hearing loss in general. In this context, a study on school age children with minimal sensorineural hearing loss has shown that these children experienced a poorer functional health status in comparison with hearing children [13]. In another study on children with congenital hearing loss (reaching from mild to profound, with 15% of all children with cochlear implants), parents reported a poorer health-related quality of life, compared to hearing peers [14]. A weakness of the latter study is that it did not include ratings of the children concerned. Proxy reports are always emergency measures, as several studies have shown [12] that the solely use of parent ratings is not unequivocal.

Until now only three studies dealing with “quality of life” of children with cochlear implants have been published [15], [16], [17]. The purpose of the first study [15] was to “quantify quality of life changes …” after a cochlear implantation. Twenty-one parents completed a self-constructed questionnaire with questions about benefits or problems, associated with the implant use, and with questions about some social activities, frustration and behavior of the child. Eleven “children” (age 6–20) completed a modified form of the parental questionnaire, or were interviewed. The purpose of the second study [16] was to know more about the stressors of families with children with implants and about the factors that helped to cope, both in the perception of the parents. Twenty-two parents were asked with a self-constructed questionnaire. One of four sections of this questionnaire contained three items “relating to measures of quality of life” [16]. Parents were asked on issues such as “independence, communication, happiness, and satisfaction” [16] for child, parents, and family. In the third study [17], 60 parents of children with cochlear implants were surveyed with a self-constructed questionnaire with questions on reactions of parents to the first information about impaired hearing of their child, about the behavior in kindergarten and in school, and about the use of hearing aids before and after implantation.

The intrinsic limitations of these studies are (1) the lack of precision and inconsistency in the use of the term “quality of life”, which furthermore do not fulfill the criteria for health-related quality of life, and (2) the manner of data collection, using self-constructed questionnaires without any validation and without any standards. Two of three studies [16], [17] are further hampered by their restriction to the solely use of parents rating QoL for their children.

In contrast to the lack of studies on children and adolescents, studies on adults with a cochlear implant are available concerning disability-specific benefit in cochlear implant programs [18], functional health status [19], and health-related quality of life [20], [21].

Furthermore, the vast majority of present studies on children and adolescents with cochlear implants fail so far to make reference to hearing children. At the same time, many parents tend to compare their (respective) child with CI with hearing counterparts and not with deaf children, especially on long term.

To obtain initial, fundamental information on health-related quality of life of children with a CI with reference to their hearing counterparts, I initiated the current pilot project with Austrian children and adolescents at school age, who were given a CI in Salzburg.