Epidemiology of permanent childhood hearing impairment: Implications for neonatal hearing screening

Risk Factors for Sensorineural Hearing Loss and Auditory Maturation in Children Admitted to Neonatal Intensive Care Units: Who Recovered?

Background: Newborns admitted to neonatal intensive care units (NICUs) are at higher risk of developing sensorineural hearing loss (SNHL), which may improve over time. The aim of this study was to describe the prevalence of the main risk factors for SNHL in a NICU cohort, focusing on children who underwent auditory maturation. Methods: An observational study of 378 children admitted to NICUs, who were followed for at least 18 months, with periodic audiologic assessments. Results: Out of 378 patients, 338 had normal hearing and 40 were hearing-impaired; we found a higher percentage of extremely preterm (EPT) and extremely low-birthweight (ELBW) infants in SNHL children (p < 0.05). Seventeen infants presented auditory improvement, with a mean maturation time of 6.17 months. A significant difference emerged between patients with stable SNHL and those who improved only in the case of hyperbilirubinemia (p = 0.005). The initial hearing threshold was a predictor of auditory improvement and moderately correlated to the time of auditory maturation (p = 0.02). Conclusions: Our study supports the trend toward recognizing worse prognoses and slower maturation processes among NICU children who suffer from severe to profound SNHL. Caution must be taken when deciding on earlier cochlear implantation.

Equivalent threshold sound pressure levels for click and CE-Chirp® stimuli delivered by the SnapPROBE™

OBJECTIVE

To estimate the equivalent threshold sound pressure levels (ETSPLs) for nine stimuli used today and in the future for universal newborn hearing screening and diagnostics delivered by the Interacoustics SnapPROBE™.

DESIGN

The Click and eight variants of the CE-Chirp^® were included to establish ETSPLs when delivered by the SnapPROBE™. The short duration stimuli were presented at a 20/s repetition rate for about 1-2 s following the international standards for establishing ETSPLs.

STUDY SAMPLE

50 ears from a total of 27 normal hearing young adult subjects (female/male = 16/11; age = 21-25 years, mean age = 23.1 years).

RESULTS

Peak-to-peak equivalent signal levels and root mean square signal levels (at 20/s repetition rate) for the nine stimuli are stated.

CONCLUSIONS

The ETSPLs are in alignment overall with those found in previous studies, while some levels are about 2-6 dB higher for this study compared to the Interacoustics Titan IOW probe and the ER-3A insert earphone. The results are relevant for present and future universal newborn hearing screening and diagnostics carried out with the SnapPROBE™ to ensure that correct stimulation levels are applied.

Assessment of hearing screening programmes across 47 countries or regions III: provision of childhood hearing screening after the newborn period

OBJECTIVE

To inventory provision and features of childhood hearing screening after the newborn period (CHS), primarily in Europe.

DESIGN

From each participating country or region, experts provided information through an extensive questionnaire: implementation year, age at screening, test method, pass criteria, screening location, screener profession, and quality indicators: coverage, referral, follow-up and detection rates, supplemented by literature sources.

STUDY SAMPLE

Forty-two European countries or regions, plus Russia, Malawi, Rwanda, India, and China.

RESULTS

CHS was performed universally with pure-tone audiometry screening (PTS) in 17 countries or regions, whereas non-universal CHS was performed in eight with PTS or whisper tests. All participating countries with universal PTS had newborn hearing screening. Coverage rate was provided from three countries, detection rate from one, and referral and follow-up rate from two. In four countries, universal PTS was performed at two ages. Earliest universal PTS was performed in a (pre)school setting by nurses (n = 9, median age: 5 years, range: 3-7), in a healthcare setting by doctors and nurses (n = 7, median age: 4.5 years, range: 4-7), or in both (n = 1).

CONCLUSIONS

Within universal CHS, PTS was mostly performed at 4-6 years by nurses. Insufficient collection of data and monitoring with quality indicators impedes evaluation of screening.

Progressive Hearing Loss in Children With Mild Bilateral Hearing Loss

Purpose This study investigated progressive hearing loss in a cohort of children who were identified with permanent mild bilateral hearing loss. Method This population-based study included 207 children with permanent mild bilateral hearing loss, diagnosed and followed from 2003 to 2016 in 1 region of Canada. Clinical characteristics and initial audiologic results were collected prospectively at diagnosis, and audiologic information was updated. Changes in hearing levels between the 1st and most recent assessment were analyzed to determine progressive hearing loss. Clinical characteristics were compared between children with progressive and stable hearing loss. The association between risk indicators and progressive hearing loss was explored through logistic regression. Results A total of 47.4% (94 of 207) had progressive hearing loss in at least 1 ear, and 50% (47 of 94) of those experienced more than 20-dB average drop in thresholds. For these 94 children, a total of 147 ears were affected, and 116 (78.9%) ears experienced sufficient change in thresholds to be coded as a worse category of hearing loss. In the subset of 85 children with more than 5 years of audiologic follow-up, 56.4% (53/85) showed a decrease in hearing. Of the total sample of 207 children, 137 (66.2%) continued to have mild hearing loss in the better ear. There was no association between the risk factors examined (family history of hearing loss, admission to the neonatal intensive care unit, or presence of a syndrome) and progressive hearing loss. Conclusion This study found that almost half of children with mild bilateral hearing loss showed a decrease in hearing in at least 1 ear. One third of the children first diagnosed with mild hearing loss in the better ear now have moderate or worse hearing loss in both ears. These findings point to the importance of careful long-term monitoring of children who present with mild hearing loss.

Lessons From an Analysis of Newborn Hearing Screening Data for Children With Cochlear Implants

OBJECTIVES

The aims of the study are to identify the limitations of the current newborn hearing screening (NHS) programs and provide recommendations for better protocols.

STUDY DESIGN

Retrospective analysis.

SETTING

Tertiary referral center.

PATIENTS

The study participants were 185 children who received cochlear implants (CIs) at ≤5 years of age.

INTERVENTIONS

Therapeutic and rehabilitative.

MAIN OUTCOME MEASURES

The results of NHS, screening tools used, age, and hearing thresholds at which hearing loss was confirmed, causes of the hearing loss, age of CI insertion, aided pure-tone audiogram findings, and language development level were analyzed.

RESULTS

NHS data was available for 109 children, and 24 patients (22.0%) had passed NHS for both ears. Hearing loss was confirmed considerably later in children who had passed NHS than in children who were referred for further evaluation (p < 0.01). The most common cause for hearing loss in the NHS-pass group was SLC26A4 mutations (41.7%). Patients in the NHS-pass group received CIs considerably later than those in the NHS-referred group (p < 0.01). Among patients with SLC26A4 mutations, the language development level was significantly lower in the NHS-pass group than in the NHS-referred group (p < 0.01).

CONCLUSIONS

Careful counseling regarding NHS results is necessary for parents to understand that the absence of hearing loss at birth does not mean that the child will not develop hearing loss later in life. Genetic testing for SLC26A4 mutations may be necessary in regions with a high incidence of these mutations, such as East Asia.

Preschool hearing screening in Sweden. An evaluation of current practices and a presentation of new national guidelines

OBJECTIVES

As the various regional authorities responsible for health care in Sweden operate independently, no knowledge was available on pre-school hearing screening available to children living in different parts of the country. The aim of this study was to carry out a survey to ascertain how preschool hearing screening was performed in the various regions of Sweden. An objective of the present paper was also to present the uniform national guidelines for pre-school hearing screening that were launched by health authorities and were based on this study. A follow-up investigation was performed to ascertain whether the new guidelines were well accepted and followed throughout the country.

METHODS

A questionnaire was sent to 25 physicians responsible for child health care centers in all 21 regions throughout the whole country. The questionnaire included detailed questions on hearing screening in preschool children. New national guidelines were introduced in cooperation with health authorities and providers of preventive child health care. After two and four years, questionnaires were sent to the same recipients to determine whether changes in practice in pre-school hearing screening had been implemented, and to obtain information about experiences with the new guidelines.

RESULTS

Sixteen of 21 regions practiced universal hearing screening of 4-yearolds. Many different protocols were used. Professionals at child health care centers expressed a need for national guidelines for pre-school hearing screening. At the two and four-year follow-ups, one more region had introduced universal hearing screening of 4-year-olds, while two regions were planning to introduce it in 2019. The new national guidelines were well accepted and used throughout the country.

CONCLUSION

There was a great variability in how pre-school hearing screening was performed in Sweden. Efforts are being made to provide uniform pre-school hearing screening. Cooperation between professionals in hearing health and health authorities is needed in order to broaden the use of universal pre-school hearing screening and to implement the new national guidelines.

Timeliness of service delivery for children with later-identified mild-to-severe hearing loss

PURPOSE

In this study, the authors examined diagnostic and intervention services for children identified with hearing loss (HL) after the newborn period.

METHOD

The authors compared ages at service delivery and length of delays between service delivery steps for 57 later-identified children with HL and 193 children who referred for assessment from the newborn hearing screen (NHS). For only later-identified children, regression models were used to investigate relationships among predictor variables and dependent variables related to service delivery.

RESULTS

Children who referred from the NHS received follow-up services at younger ages than later-identified children. Later-identified children had significantly longer delays from HL confirmation to entry into early intervention, compared to children who referred from the NHS. For later-identified children, degree of HL predicted ages at follow-up clinical services. Children with more severe HL received services at younger ages compared to children with milder HL. Gender predicted the length of the delay from confirmation to entry into early intervention, with girls demonstrating shorter delays.

CONCLUSIONS

The current results lend support to the need for ongoing hearing monitoring programs after the neonatal period, particularly when children enter early intervention programs because of language/developmental delays.

An Evidence-Based Systematic Review on the Diagnostic Accuracy of Hearing Screening Instruments for Preschool- and School-Age Children

PURPOSE

The purpose of this article is to conduct an evidence-based systematic review on the accuracy of pure-tone or otoacoustic emission (OAE) screening for identifying hearing loss in preschool- and school-age children.

METHOD

A systematic search of the literature published between 1975 and 2013 was conducted. Articles meeting the selection criteria were critically appraised for quality. Selection criteria required that behavioral thresholds be measured in children failing the screen and in at least a subset of children passing the screen. Sensitivity and specificity were used to calculate positive and negative likelihood ratios that could be compared between instruments.

RESULTS

Eighteen studies were included in the final analysis. There was considerable variability among studies on stimulus levels, response criteria, and definition of hearing loss. Approximately half of positive and negative likelihood ratio pairs for OAEs (52%) and pure-tone screening (45%) were considered suggestive or informative for identifying hearing loss.

CONCLUSIONS

Both pure-tone and OAE screening can identify hearing loss in preschool- and school-age children. Studies that compared both tools in the same population concluded that pure-tone screening had higher sensitivity than OAE screening and thus was considered the preferred tool. Future research should incorporate standard stimulus levels, response criteria, and definitions of hearing loss.

Prelingual sensorineural hearing loss and infants at risk: Western Sicily report

OBJECTIVE

To evaluate independent etiologic factor associated with sensorineural hearing loss (SNHL) in newborn at risk; to study the role of their interaction especially in NICU infants who present often multiple risk factors for SNHL.

METHODS

The main risk factors for SNHL reported by JCIH 2007 were evaluated on 508 infant at risk ranging from 4 to 20 weeks of life, transferred to the Audiology Department of Palermo from the main births centers of Western Sicily. After a global audiological assessment, performed with TEOAE, tympanometry and ABR, the prevalence and the effect of risk factors was statistically studied through univariate and multivariate analysis on the total population (normal and deaf subjects).

RESULTS

Fifty-one infants (10.03%) were diagnosed with SNHL (45 bilateral and 6 monolateral) with a mean hearing threshold of 87.39 ± 28.25 dB HL; from logistic regression analysis family history of hearing impairment (HI) and TORCH infections resulted independent significant risk factors (P<0.00001 and P=0.024 respectively). High SNHL percentages were evidenced also in NICU babies, due to the various pathologies and risk factors presented by these infants, and among newborns who suffered from hyperbilirubinemia requiring exchange transfusion (11.97% and 9.52% respectively). Craniofacial abnormalities (CFA) and syndromes associated to HI showed an important relationship (P<0.00001) with conductive hearing loss (CHL). Multiple regression analysis of the variation in SNHL among NICU infants evidenced an increased risk for SNHL of 21.24% and of 19.33% respectively in preterm infants and in case of hyperbilirubinemia if respiratory distress is concomitant with these risk factors. It was also observed an higher risk of SNHL (99.66%) in case of coexistence of prematurity and hyperbilirubinemia. Finally among infants with very low birth weight (VLBW) it was evidenced a statistically difference between the mean weight of SNHL infants respect to NHL newborns (P=0.048).

CONCLUSION

The high SNHL prevalence (10.03%) in our cohort underlines how infants at risk are more susceptible to suffer from SNHL; in particular NICU newborns have a 33% greater chance of developing SNHL, because of the presence of multiple risk factors (or=1.33) and their interaction. As the number of coexisting risk factors increases, the prevalence of SNHL also increases (r(2)=0.93).

Audiologic profile of infants at risk: experience of a Western Sicily tertiary care centre

OBJECTIVE

To identify the incidence of sensorineural hearing loss (SNHL) on infant at risk and to classify the degree and type of hearing loss describing the main causes associated in Western Sicily. To compare single TEOAE and combined TEOAE/ABR techniques studying the referral rate, the false-positive and false-negative rates through concordance test (κ coefficient), sensitivity (TPR) and specificity (TNR) for each protocol.

METHODS

From January 2010 to June 2011, 412 infants at risk, ranging from 4 to 20 weeks of life, transferred to Audiology Department of Palermo from the births centers of Western Sicily, underwent to audiological assessment with TEOAE, tympanometry and ABR. The following risk factors were studied: family history of SNHL, consanguinity, low birth weight, prematurity, cranio-facial abnormality and syndromes associated to SNHL, respiratory distress, intensive care in excess of 5 days (NICU), pregnant maternal diseases, perinatal sepsis or meningitis, hyperbilirubinemia, ototoxic drugs administration.

RESULTS

Forty-seven infants (11.41%) were diagnosed with SNHL; median corrected age at final audiological diagnosis was 12 weeks. SNHL resulted moderate in 44.68%, severe in 10.64% and profound in 21 cases with a significant difference in family history and NICU infants (p<0.0001). As the number of coexisting risk factors increases, the percentage value of SNHL in infants (χ(2)=12.31, p=0.01, r(2)=0.98) and the degree of hearing loss (χ(2)=13.40, p=0.0095, r=0.92) also increase. The study of single TEOAE and combined TEOAE/ABR showed a statistical difference (χ(2)=14.89, p<0.001) with a low concordance value (κ=0.87) confirming the importance of combined techniques for NICU group (κ=0.86) where four cases (0.97%) of auditory neuropathy were diagnosed.

CONCLUSION

This study demonstrates the necessity to implement a neonatal hearing screening program in Western Sicily because of the high percentage of SNHL in infants at risk. Family history of HL is an independent significant risk factor for SNHL easily diagnosed through single TEOAE technique. Combined TEOAE/ABR is the gold standard for NICU babies which are at risk for auditory neuropathy. Coexisting risk factors are an additional risk factor for HL.

Development of an integrated child health information system for children who are deaf or hard of hearing

Young children who are deaf or hard of hearing typically participate in health and early intervention service structures involving multiple agencies and service providers, all of whom may be responsive to a child's and family's needs, but remain mutually distinct with minimal interdependence. Lack of coordination may result in fragmented service delivery and may be counterproductive to the provision of family centred services. Increasingly, advancements in technology, such as the development of integrated child health information systems, have facilitated greater coordination and integration of service delivery in multidisciplinary and multisite program contexts. In the present article, the process of developing an integrated child health information system for a new provincial early hearing detection and intervention program in British Columbia is described. Key considerations for system development included the following: the nature of the preprogram structure for information management and sharing; the need for modifications of the structure; and ways that the structure could be improved.

Universal neonatal audiological screening: experience of the University Hospital of Pisa

The early identification of pre-lingual deafness is necessary to minimize the consequences of hearing impairment on the future communication skills of a baby. According to the most recent international guidelines the deafness diagnosis must occur before the age of three months and the prosthetic-rehabilitative treatment with a traditional hearing aid should start within the first six months. When a Cochlear implant becomes necessary, the treatment should start between the age of 12 months and 18 months. The only way to diagnose the problem early is the implementation of universal neonatal audiological screening programs. Transient evoked otoacoustic emissions (TEOAE) is the most adequate test because it's accurate, economic and of simple execution. Automatic auditory brainstem response (AABR) is necessary to identify patients with auditory neuropathy but it is also important to reduce the number of false-positives.The 20-30% of infant hearing impairment is represented by progressive or late-onset hearing loss (HL) so it's also necessary to establish an audiological follow up program, especially in infants at risk.From November 2005 all neonates born in the University hospital of Pisa undergo newborn hearing screening. From 2008 the screening program follows the guidelines for the execution of the audiological screening in Tuscany which have been formulated by our group according to the 2007 JCIH Position Statement and adaptated to our regional reality by a multidisciplinary effort. From November 2005 to April 2009 8113 neonates born in the Neonatal Unit of Santa Chiara Hospital (Pisa) have undergone newborn hearing screening. 7621 neonates (93.9%) without risk factors executed only the TEOAE test. 492 (6.1%) neonates had audiological risk factors and thus underwent TEOAE and AABR. 84 patients (1,04%) failed both TEOAE and AABR tests. 78 of them underwent further investigations. 44 patients resulted false positives (the 0,54% of the screened newborns). 34 neonates (4,2 ‰) had a final diagnosis of hearing impairment. 8 patients (0.99 ‰) had unilateral hearing loss (HL). 26 patients (3,2 ‰) had bilateral hearing impairment.In our screening program the percentage of false-positives was quite low (0.54%) while the incidence of bilateral HL (3.2 ‰) is a little higher than that found in literature reports. In most of our patients premature birth or neonatal suffering represent the main cause of HL.

Universal newborn hearing screening in the Champagne-Ardenne region: a 4-year follow-up after early diagnosis of hearing impairment

INTRODUCTION

Permanent congenital hearing loss is one of the most frequent congenital anomaly at birth. Universal newborn hearing screening (UNHS) was introduced in numerous countries in order to allow an early diagnosis and intervention for congenital hearing impairment.

OBJECTIVE

First aim of this study is to evaluate the accuracy of early diagnosis of hearing impairment after UNHS. Second aim is to discuss the auditory intervention proposed after this diagnosis. Last aim is to evaluate the relevance of UNHS for early diagnosis and intervention.

MATERIALS AND METHODS

Prospective study. UNHS program was introduced in the entire French region of Champagne-Ardenne in January 2004. Forty-one children have benefited of an early diagnosis of hearing impairment until June 2007. They were included in an intervention program consisting of an audiometric follow-up and an auditory intervention. This program was conducted until June 2008.

RESULTS

There were 28 males patients and 13 females patients. The diagnosis of hearing aid impairment was carried at an average age of 3.2-month. The auditory follow-up allowed confirming the initial diagnosis of deafness for the majority of the children as for their degree of hearing loss. Auditory intervention was heterogeneous depending on degree of hearing loss of the children.

CONCLUSION

This UNHS program demonstrates its validity and feasibility for early diagnosis and intervention of congenital hearing impairment. It brought a major impact on the management of congenital hearing impairment in Champagne-Ardenne.

Place of birth and characteristics of infants with congenital and early-onset hearing loss in a developing country

OBJECTIVE

To determine the characteristics of infants with sensorineural hearing loss (SNHL) and the relationship with place of birth.

METHODS

Subjects were drawn from hospital-based and community-based universal infant hearing screening programs concurrently conducted from May 2005 to April 2008 in Lagos, Nigeria. Maternal and infant characteristics of children born in hospitals and detected with SNHL were compared with those born outside hospitals. Each program consisted of a first-stage screening with transient-evoked otoacoustic emissions (TEOAE) followed by second-stage automated auditory brainstem response (AABR). Hearing status was confirmed by diagnostic auditory brainstem response, tympanometry and visual response audiometry.

RESULTS

A total of 4718 infants were screened under the hospital-based program out of which 12 (0.3%) infants were confirmed with SNHL whereas 71 (1.0%) of the 7179 infants screened under the community-based program were confirmed with SNHL. Of all infants with SNHL 39 (47.0%) were born in hospitals suggesting that 27 (38.0%) of infants under the community-based program were born in hospitals. Prevalence of SNHL ranged from 4.0 per 1000 among infants born in government hospitals to 23 per 1000 among those born in family homes. Mothers of those born outside hospitals were significantly likely to belong to the Yoruba tribe (p<0.001), use herbal medications in pregnancy (p<0.001), deliver vaginally (p=0.004) but without skilled attendants at delivery (p<0.001). There were no significant differences among the infants themselves except that those born outside hospitals were significantly likely to be detected in the first 3 months of life compared to those born in hospitals (p<0.001).

CONCLUSIONS

A significant proportion of infants with SNHL in many developing countries are likely to be born outside hospitals thus underscoring the need for community-oriented UNHS to facilitate early detection and intervention. Conventional risk factors for SNHL are unlikely to discriminate across places of birth. Pediatricians and otolaryngologists should consider a more active role in fostering community-oriented delivery of primary ear care services in this and similar settings in the developing world.

Post-natal hearing loss in universal neonatal hearing screening communities: current limitations and future directions

Universal hearing screening has dramatically improved outcomes for babies born with detectable hearing abnormalities; yet there are some infants who develop significant hearing problems after passing a neonatal screen. There is much conjecture as to the number and the characteristics of infants with post-natal hearing losses; yet evidence suggests that many children may be affected, and that a large proportion have no discoverable cause. Currently, screening programmes use lists of risk factors to enroll babies into surveillance programmes. This practice is problematic because audiological follow-ups are expensive and under-utilised, and parental disclosure is often inaccurate. The large databases from universal neonatal programmes could inform the development of effective, evidence-based practice and policy for the detection and intervention of children who develop post-natal hearing losses.

Newborn hearing screening project using transient evoked otoacoustic emissions: Western Sicily experience

OBJECTIVE

To study the incidence of congenital sensorineural hearing loss in all newborns introducing a screen test with a protocol no expensive, with a good "screen sensitivity" that could let an earlier identification of hearing impairment beginning early intervention by 2 months of age and increasing the probability of having language development within the normal range of development.

METHODS

The study was conducted in Sciacca hospital from the beginning of 2003 to our days and was carried out with transient evoked otoacoustic emission using the criteria for PASS or RETEST and considering eventual prenatal and perinatal risk factors. All the newborns were divided into four groups each one with its personal secondary step program.

RESULTS

In the years 2003-2004 the number of the newborns in Sciacca hospital was: 538 for 2003, 653 for 2004 with a total of 1191; all these infants were divided in three groups: resident in Sciacca, resident in the Sciacca borderlands and resident out of the district of Sciacca. The coverage (percentage of the target population who undergo the screen) was of 90% in the 2003 (483 newborns) and of 90% in the 2004 (585 newborns) with two cases of congenital sensorineural hearing loss identified. The incidence of sensorineural hearing loss, in the District of Sciacca, was estimated to be 2.07/1000 in 2003 and 1.70/1000 in 2004.

CONCLUSIONS

The higher incidence of sensorineural hearing loss in our study is due to a high prevalence of consanguineous marriage in Sicily that was shown to be linked with hearing impairment. The "sensitivity value" was 95% at the first step but became 99% after the second step with a few number of false positive (0.74%). All the infants with a diagnosis of sensorineural hearing loss began a rehabilitation program before the age of 5 months and they have a good speech development and speech intelligibility.

An exploration of demographic bias in a questionnaire survey of hearing-impaired children: implications for comparisons of children with and without cochlear implants

OBJECTIVES

Responders to questionnaire surveys, who are self-selecting, are generally accepted to be unrepresentative of the total available population, at least in demographic terms. Since demographic and other variables are known to be predictive of outcome, it is important to understand the extent of that unrepresentativeness when using survey data to report comparisons of outcome. This paper aims (i) to evaluate the extent to which a sample of hearing-impaired children surveyed by postal questionnaire was representative of the population of hearing-impaired children in the United Kingdom (UK), and (ii) to identify demographic differences between children with and without cochlear implants.

METHODS

Data from a previously reported total ascertainment of hearing-impaired children in the UK which identified 17,160 with permanent bilateral hearing impairment >40 dB HL were compared with data collected by postal questionnaire for a sample of 3224 children, including 527 with cochlear implants.

RESULTS

The sampled children were similar to the ascertained population in gender, age at onset of hearing impairment, and number of additional disabilities, but came from more recent birth cohorts and from more affluent families. Compared with profoundly impaired non-implanted children, implanted children had greater degrees of hearing loss, fewer additional disabilities, a later age of onset, were younger, came from more affluent families, were more likely to use spoken language at home, and to be taught using spoken language only.

CONCLUSIONS

Comparisons of outcomes and generalisation of results require adjustment for relevant variables to avoid confounding estimates of the effectiveness of interventions including cochlear implantation.

Hearing-impaired children in the United Kingdom, I: Auditory performance, communication skills, educational achievements, quality of life, and cochlear implantation

OBJECTIVES

The objectives of this study were to identify variables that are associated with differences in outcome among hearing-impaired children and to control those variables while assessing the impact of cochlear implantation.

STUDY DESIGN

In a cross-sectional study, the parents and teachers of a representative sample of hearing-impaired children were invited to complete questionnaires about children's auditory performance, spoken communication skills, educational achievements, and quality of life. Multiple regression was used to measure the strength of association between these outcomes and variables related to the child (average hearing level, age at onset of hearing impairment, age, gender, number of additional disabilities), the family (parental occupational skill level, ethnicity, and parental hearing status), and cochlear implantation.

RESULTS

Questionnaires were returned by the parents of 2858 children, 468 of whom had received a cochlear implant, and by the teachers of 2241 children, 383 of whom had received an implant. Across all domains, reported outcomes were better for children with fewer disabilities in addition to impaired hearing. Across most domains, reported outcomes were better for children who were older, female, with a more favorable average hearing level, with a higher parental occupational skill level, and with an onset of hearing-impairment after 3 years. When these variables were controlled, cochlear implantation was consistently associated with advantages in auditory performance and spoken communication skills, but less consistently associated with advantages in educational achievements and quality of life. Significant associations were found most commonly for children who were younger than 5 years when implanted, and had used implants for more than 4 years. These children, whose mean (preoperative, unaided) average hearing level was 118 dB, were reported to perform at the same level as nonimplanted children with average hearing levels in the range from 80 dB to 104 dB, depending on the outcome measure.

CONCLUSIONS

When rigorous statistical control is exercised in comparing implanted and nonimplanted children, pediatric cochlear implantation is associated with reported improvements both in spoken communication skills and in some aspects of educational achievements and quality of life, provided that children receive implants before 5 years of age.

Longitudinal study of hearing impairment in children

The aim of this study is to evaluate the frequency of progression in permanent childhood hearing impairment (PHI) and to relate potential specific factors to the eventual progression. A description is made of the true longitudinal hearing thresholds in four groups of children according to different observation periods and being part of a prospective pediatric audiological registry-based study established in 1989. At the time of data collection the registry included 1373 children born after 1/1-1970 with a PHI > 20 dB in either the right or the left ear at any pure tone frequency. The children were subdivided according to the following observation periods: 1-3 years (N=266), >3-5 years (N=148), >5-10 years (N=212) and >10 years (N=62). The differences from the first to the most recent audiometric thresholds were analysed for the right and left ears separately, at the pure tone frequencies 250, 500, 1000, 2000, 4000 and 8000 Hz, for the average of 500, 1000, 2000 and 4000 Hz, for the average of 2000 and 4000 Hz and for the average of 4000 and 8000 Hz. Those showing a progression >15 dB for the average across 500-4000 Hz were analysed for age at onset and aetiology of hearing impairment, showing that genetic factors are predominant in progressive PHI. It was also found that progression in PHI is most frequent in early childhood but found only in 5.7% after the age of 4 years.