Karl R. White

Sensorineural hearing loss in children

During the past three to four decades, the incidence of acquired sensorineural hearing loss (SNHL) in children living in more developed countries has fallen, as a result of improved neonatal care and the widespread implementation of immunisation programmes. The overall decrease has been accompanied by a relative increase in the proportion of inherited forms of SNHL. The contribution made by one gene in particular, GJB2, to the genetic load of SNHL has strongly affected the assessment and care of children with hearing loss. These changes in the incidence of SNHL have not been seen in children living in less developed countries, where the prevalence of consanguinity is high in many areas, and both genetic and acquired forms of SNHL are more common, particularly among children who live in poverty. Focused genetic counselling and health education might lead to a decrease in the prevalence of inherited SNHL in these countries. Establishment of vaccination programmes for several vaccine-preventable infectious diseases would reduce rates of acquired SNHL. Although the primary purpose of such programmes is the prevention of serious and in many cases fatal infections, a secondary benefit would be a reduction in disease-related complications such as SNHL that cause permanent disability in survivors.

Does Research Support Claims About the Benefits of Involving Parents in Early Intervention Programs

It is widely believed that early intervention programs that involve parents are more effective than those that do not. After discussing the types of parent involvement programs that have been implemented in previous early intervention research and defining the benefits which are allegedly associated with the involvement of parents in early intervention programs, this article presents an analysis of the evidence from previous research regarding the alleged benefits. This analysis shows that there is no convincing evidence that the ways in which parents have been involved in previous early intervention research studies result in more effective outcomes. Possible reasons for the lack of observed benefits are offered, and suggestions are made for future research and practice.

A Multicenter Evaluation of How Many Infants With Permanent Hearing Loss Pass a Two-Stage Otoacoustic Emissions/Automated Auditory Brainstem Response Newborn Hearing Screening Protocol

Objective. Ninety percent of all newborns in the United States are now screened for hearing loss before they leave the hospital. Many hospitals use a 2-stage protocol for newborn hearing screening in which all infants are screened first with otoacoustic emissions (OAE). No additional testing is done with infants who pass the OAE, but infants who fail the OAE next are screened with automated auditory brainstem response (A-ABR). Infants who fail the A-ABR screening are referred for diagnostic testing to determine whether they have permanent hearing loss (PHL). Those who pass the A-ABR are considered at low risk for hearing loss and are not tested further. The objective of this multicenter study was to determine whether a substantial number of infants who fail the initial OAE and pass the A-ABR have PHL at ∼9 months of age. Methods. Seven birthing centers with successful newborn hearing screening programs using a 2-stage OAE/A-ABR screening protocol participated. During the study period, 86634 infants were screened for hearing loss at these sites. Of those infants who failed the OAE but passed the A-ABR in at least 1 ear, 1524 were enrolled in the study. Data about prenatal, neonatal, and socioeconomic factors, plus hearing loss risk indicators, were collected for all enrolled infants. When the infants were an average of 9.7 months of age, diagnostic audiologic evaluations were done for 64% of the enrolled infants (1432 ears from 973 infants). Results. Twenty-one infants (30 ears) who had failed the OAE but passed the A-ABR during the newborn hearing screening were identified with permanent bilateral or unilateral hearing loss. Twenty-three (77%) of the ears had mild hearing loss (average of 1 kHz, 2 kHz, and 4 kHz ≤40-decibel hearing level). Nine (43%) infants had bilateral as opposed to unilateral loss, and 18 (86%) infants had sensorineural as opposed to permanent conductive hearing loss. Conclusions. If all infants were screened for hearing loss using the 2-stage OAE/A-ABR newborn hearing screening protocol currently used in many hospitals, then ∼23% of those with PHL at ∼9 months of age would have passed the A-ABR. This happens in part because much of the A-ABR screening equipment in current use was designed to identify infants with moderate or greater hearing loss. Thus, program administrators should be certain that the screening program, equipment, and protocols are designed to identify the type of hearing loss targeted by their program. The results also show the need for continued surveillance of hearing status during childhood.

Efficacy of Early Intervention

Based on an analysis of over 300 previous studies of early intervention efficacy, this article explains how the steps in the scientific method can be used to organize and draw conclusions from existing research. Although it is concluded that early intervention has positive benefits for most children, it is pointed out that there is little, if any, empirical support for the types of intervention that are most effective. Suggestions for future research are given.

The effectiveness of screening programs based on high-risk characteristics in early identification of hearing impairment.

Prompt identification of educationally significant hearing loss is yet an unattained goal. However, there is some evidence that the ability to identify and diagnose hearing loss at an early age has been significantly improved through the use of carefully designed screening protocols such as birth certificate-based high-risk registries. To evaluate the efficiency of birth certificate-based screening programs, 70 parents and guardians of 6- to 9-yr-old children with significant sensorineural losses were surveyed regarding their childs identification history. Each of these children was born in the state during the time a birth certificate-based screening program was in full operation. Results indicate that children with at least one risk factor for hearing impairment were identified an average of 7.7 mo earlier than children with no risk history. However, only 50% of the children with sensorineural hearing losses exhibited any of the risk factors and a significant number of children with risk factors were missed by the system. Had admission to a neonatal intensive care unit been considered a risk factor, 63% of the children would have exhibited at least one risk factor. More extensive implementation of high-risk registries in conjunction with more widespread education of parents and primary care providers regarding early behavioral indicators of hearing loss, procedures for referral, and appropriate intervention and management services needs to be considered.

Genetics Evaluation Guidelines for the Etiologic Diagnosis of Congenital Hearing Loss

The advent of hearing screening in newborns in many states has led to an increase in the use of genetic testing and related genetic services in the follow-up of infants with hearing loss. A significant proportion of those with congenital hearing loss have genetic etiologies underlying their hearing loss. To ensure that those identified with congenital hearing loss receive the genetic services appropriate to their conditions, the Maternal and Child Health Bureau of the Health Resources and Services Administration funded the American College of Medical Genetics to convene an expert panel to develop guidelines for the genetic evaluation of congential hearing loss. After a brief overview of the current knowledge of hearing loss, newborn screening, and newborn hearing screening, we provide an overview of genetic services and a guideline that describes how best to ensure that patients receive appropriate genetic services. The significant contribution of genetic factors to these conditions combined with the rapid evolution of knowledge about the genetics of these conditions overlaid with the inherently multidisciplinary nature of genetic services provides an example of a condition for which a well-integrated multidisciplinary approach to care is clearly needed.The advent of hearing screening in newborns in many states has led to an increase in the use of genetic testing and related genetic services in the follow-up of infants with hearing loss. A significant proportion of those with congenital hearing loss have genetic etiologies underlying their hearing loss. To ensure that those identified with congenital hearing loss receive the genetic services appropriate to their conditions, the Maternal and Child Health Bureau of the Health Resources and Services Administration funded the American College of Medical Genetics to convene an expert panel to develop guidelines for the genetic evaluation of congential hearing loss. After a brief overview of the current knowledge of hearing loss, newborn screening, and newborn hearing screening, we provide an overview of genetic services and a guideline that describes how best to ensure that patients receive appropriate genetic services. The significant contribution of genetic factors to these conditions combined with the rapid evolution of knowledge about the genetics of these conditions overlaid with the inherently multidisciplinary nature of genetic services provides an example of a condition for which a well-integrated multidisciplinary approach to care is clearly needed.

Screening all newborns for hearing loss using transient evoked otoacoustic emissions

The importance of identifying hearing loss before 12 months of age is well established. Although recent research provides some evidence for the value of transient evoked otoacoustic emissions (TEOAEs) in newborn hearing screening, data are needed from large-scale clinical evaluations about the value of using TEOAE for screening high-risk and healthy babies. A cohort of 1850 infants from the well-baby nursery (WBN) and neonatal intensive care unit (NICU) were screened with TEOAE using a 2-stage process. Infants referred from the first stage prior to being discharged from the hospital were rescreened 4 to 6 weeks later. Those who did not pass the second-stage TEOAE screening were referred for diagnostic auditory brainstem response (ABR) and/or behavioral audiological evaluation for confirmation of hearing loss, fitting with amplification, and enrollment in early intervention programs. Eleven infants with unilateral or bilateral sensorineural hearing loss > 25 dB (a prevalence of 5.95 per 1000) and 37 with unilateral or bilateral recurrent conductive hearing loss > 25 dB (a prevalence of 20.0 per 1000) were identified from this cohort. These results suggest that TEOAE is a promising technique for screening newborns for hearing loss and should be evaluated further as a tool for universal newborn hearing screening.

An integrative review of early intervention efficacy studies with at-risk children: Implications for the handicapped

Results of 162 early intervention efficacy studies with disadvantaged, at-risk, and handicapped children were analyzed to draw conclusions about the efficacy of early intervention, identify variables which covary with effectiveness, and identify areas for future research. Because of the scarcity of data and methodological problems with efficacy studies with handicapped children, much of the paper focuses on conclusions drawn from research with disadvantaged and at-risk populations and the implications of those data for handicapped children. It is concluded that early intervention has substantial immediate benefits for at-risk and disadvantaged children. What few data are available about the effects of parental involvement, age at which intervention starts, training of the intervenor, and maintenance of effects are often contrary to what many people have assumed. Methodological suggestions to improve future early intervention research are discussed.

Teacher-Student Interaction Patterns in Classrooms with Mainstreamed Mildly Handicapped Students

Teacher-student interaction patterns in 12 third-grade mainstreamed classrooms were observed with four groups of students: (1) nonhandicapped high achievers, (2) nonhandicapped low achievers, (3) learning disabled, and (4) behaviorally handicapped. Teacher-student interaction was defined using 16 dependent measures derived from the Brophy-Good Teacher-Child Dyadic Interaction System. Multivariate and Univariate Analysis of Variance procedures demonstrated that statistically the groups were significantly different on 8 of the 16 dependent measures. Although the behaviorally handicapped students were treated differently by their regular classroom teachers more frequently than students in the other three groups, no group was given consistent preferential treatment. Most student initiations were nonacademic, and almost one-half of teachers’ feedback and initiations were nonacademic. Furthermore, teachers used more disapproving than positive feedback. The results indicate a need for teachers in mainstreamed classrooms to devote more time to academic tasks and to use better classroom management techniques.

Evaluation of the Universal Newborn Hearing Screening and Intervention Program

During the last 20 years, the number of infants evaluated for permanent hearing loss at birth has increased dramatically with universal newborn hearing screening and intervention (UNHSI) programs operating in all US states and many territories. One of the most urgent challenges of UNHSI programs involves loss to follow-up among families whose infants screen positive for hearing loss. We surveyed 55 state and territorial UNHSI programs and conducted site visits with 8 state programs to evaluate progress in reaching program goals and to identify barriers to successful follow-up. We conclude that programs have made great strides in screening infants for hearing loss, but barriers to linking families of infants who do not pass the screening to further follow-up remain. We identified 4 areas in which there were barriers to follow-up (lack of service-system capacity, lack of provider knowledge, challenges to families in obtaining services, and information gaps), as well as successful strategies used by some states to address barriers within each of these areas. We also identified 5 key areas for future program improvements: (1) improving data systems to support surveillance and follow-up activities; (2) ensuring that all infants have a medical home; (3) building capacity beyond identified providers; (4) developing family support services; and (5) promoting the importance of early detection.