Measuring the prevalence of permanent childhood hearing impairment

Methods of hearing assessment in children

Hearing problems can have a significant impact on a child's language and general development, and therefore early detection is important. Doctors dealing with children need to understand the various types of hearing assessment and their limitations.

Accelerating evidence into practice for the benefit of children with early hearing loss

Over the years, multiple groups have issued recommendations for newborn hearing screening, diagnosis, and intervention. In January 2008, the US Department of Health and Human Services held an invitational workshop at which more than 50 national experts met for 2 days to consider ways to accelerate the movement of evidence-based recommendations into practice. Participants set priorities among existing recommendations, identified areas with the most promise and created a national blueprint to accelerate evidence into practice. Workshop participants adopted the "3T's Roadmap to Transform US Health Care" as the conceptual model for this work and used a modified Delphi process to identify high-priority recommendations in 5 areas (diagnosis, treatment, parental and public awareness, continuous quality improvement, and stewardship). A matrix of responsibility was developed to specify entities that could take action to implement these recommendations. Participants placed a high priority on measurement and recommended improved data-tracking of newborns after screening and creation of a limited set of national indicators to monitor progress toward evidence-based system goals. They also identified a greater role for parents and families in contributing to system transformation and a need for more culturally and linguistically appropriate resources. Targeting infants in the NICU for early testing and creating guidelines and resources for early intervention were additional priorities. Finally, the work group noted the need to create a stewardship function to monitor the progress of the entire system of care, disseminate reports, consider future research directions, and continue to develop critical cross-agency and public-private coordination of activities.

Epidemiology of congenital hearing loss in Victoria, Australia: Epidemiología de la hipoacusia congénita en Victoria, Australia

The aim of this study was to report the incidence, prevalence and clinical characteristics of congenital hearing loss sufficient to require hearing aid fitting in the first 6 years of life for the 1993 birth cohort of the state of Victoria (population 4.4 million), Australia. In 1993, 64,116 infants born in the state of Victoria survived the neonatal period. Subjects included all children with congenital hearing loss for which hearing aids were fitted, at any time up to and including 31 December 1999, when the youngest member of the cohort reached 6 years of age. Data on the degree, type and etiology of hearing loss were available from the Australian Hearing database for all subjects. Sociodemographic and health data were available from the Victorian Infant Hearing Screening Program (VIHSP) and parent questionnaires. The known prevalence of identified congenital hearing loss increased as the cohort aged. By the time the youngest member had reached the age of 6 years, 134 children (78 boys, 56 girls) had been fitted with hearing aids for permanent congenital hearing loss of any degree (2.09/1000). Fifty-four (40%) of these had known mild losses (20-40 dB HL). The prevalence of known moderate or greater loss (> 40 dB HL) was 1.12/1000; the data suggest that over 90% could have been detectable by neonatal hearing screening. A further seven children from the birth cohort were fitted with hearing aids due to acquired forms of hearing loss (0.11/1000). The etiology was known in only 57 (43%) congenital cases, with known non-syndromal genetic causes accounting for 21 (37%) of these. This study reports on the prevalence of congenital hearing loss requiring hearing aid fitting for an entire birth cohort. These data indicate the possible yield from neonatal screening, and hence the likely benefit of such screening. For a large proportion of cases, the etiology remains unknown. These data have implications for health service delivery and illustrate the usefulness of a population database in monitoring the prevalence of congenital hearing loss.

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.

Universal neonatal hearing screening moving from evidence to practice

Recent technological advances have made feasible universal newborn hearing screening and therefore early detection of permanent childhood hearing impairment. Over the past three years, new information has been published on whether early intervention is beneficial, the possibility of harm arising from newborn screening, and its cost. Dramatic progress has been made in the large scale implementation of universal screening in many parts of the western world.