February -March 2002: Newborn Hearing Programs in Brazil. Models Outside the US reality. PART 1
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- Last Updated on Monday, 31 March 2014 10:02
- Written by Katia de Almeida, PhD
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1. Introduction
All around the world, the issue regarding the newborn hearing screening has been discussed among different kinds of professionals, and the hope lies on the early detection, diagnosis and intervention of hearing loss in very young children.
The past decade in Brazil was of great importance for the development of newborn hearing screening. The Brazilian Task Force on Universal Newborn Hearing Screening – Grupo de Apoio a Triagem Auditiva Neonatal (GATANU) - was founded in 1998 and an important step was given towards the implementation of screening programs in hospitals. Also, in October 1998, it was created the Brazilian Committee on Infant Hearing (Comitê Brasileiro sobre Perdas Auditivas Na Infância 2000) with members from the Brazilian Societies of Otolaryngology, Pediatrics, Speech Pathology/Audiology and other national organizations. In November 1999 the Committee finished the first consensus about the newborn hearing screening (NHS) program. It was recommended that all newborns should be screened for hearing loss before hospital discharge, or at most by 3 months of age.
Brazil has approximately 170.000.000 inhabitants (IBGE,2000). A developing and huge country with several economical and political particularities and regional diversities. If we consider the estimated number of 3.500.000 live births per year (FUNASA, 2000), and the prevalence of bilateral sensorineural hearing loss in this population as 3:1000, we will have around 10.500 new hearing impaired babies every year. Also, some local studies have showed that the diagnosis of congenital hearing loss is made after 24 months of age. These facts are sufficient to make us move on… We got a lot of work to do!!!
Nowadays, universal newborn hearing screening (UNHS) program is not required by law in any State, but it is performed routinely in many of them. Some cities have laws which demand that every child born must have his hearing tested, but not every hospital in these counties perform the screening yet. In the year of 2001 we acknowledged 75 NHS programs in 16 different states, and 39 of them are located in Sao Paulo. Last year we had half of the amount of programs. The distribution of these programs among the states , taken from the web site www.gatanu.org is shown in Fig. 1.
Figure1:
2. Protocols and Testing Results
Who pays the cost of the Newborn Hearing Screening Programs? Most of the programs are supported by parents who are in charge of their baby hearing screening. Very few Health Insurance Cos covers the neonatal hearing screening. This cost varies from US$ 16,00 to 40,00 dollars, deppending on the hospital policies. Very few hospitals offer the screening without charging the parents.
The professional team in NHS programs in Brazil involves audiologists, pediatricians and otolaryngologists. Many of these programs are coordinated by audiologists, and some by pediatricians or otolaryngologists. The audiologists are responsible for choosing and performing the protocols, parents counseling and orientation, and also for the follow-up in case of failure in the hearing screening.
The screening test is generally accomplished prior to the hospital discharge, within 48 hours of birth, unless the babies are admitted in the neonatal intensive care unit (NICU).
Two types of tests are commonly used: otoacoustic emissions (OAEs) and auditory brainstem response (ABR). Typically, screening programs use a two-stage screening approach (OAE-OAE, OAE-ABR or ABR-ABR).
Children who fail in-hospital screening tests usually are asked to return to the hospital in order to be re-screened after 4 weeks after discharge. Positive results are usually validated by combination of otolaryngologic and audiologic examinations, before the age of 3 months. The Brazilian Committee endorses the recommendation(s) of the Joint Committee on Infant Hearing (2000) that infants with confirmed hearing loss should receive intervention before 6 months of age. This is our real challenge, to guarantee the necessary follow up and intervention that should follow the screening test.
The first hospital to perform a newborn hearing screening was Hospital Israelita Albert Einstein, in São Paulo, Brazil. Below we report partially some results (taken from Chapchap and Segre, 2001) "From September 1996 to August 1999, 4631 babies were born at the maternity of Hospital Israelita Albert Einstein and 4196 (90,6%) had a hearing screening performed on the 2nd or 3rd day for the well-baby population, and before discharge for the NICU population. The TEOAE were recorded with an ILO88 OAE Analyser, software version 4.2, using the non-linear technique and "quickscreen" mode (time-window from 2.5 to 12 ms). A 2 stages protocol was used as shown in Fig. 2 and Fig. 3. The pass criteria chosen was the presence of 3 out 4 frequency bands evaluated with signal to noise ratio >= 3 dB for the 1.6 kHz or reproducibility >=50% and signal to noise ratio >=6 dB for the 2.4, 3.2 and 4.0 kHz or reproducibility >= 70%; total repro>=50%; probe stability > 70%. The considered stimulus level varied among 78 and 85 dB SPL. A minimum of 50 low noise sweeps was required. The software HI*screen and Hi*track were used for data collecting, management and analysis. The parents were personally informed by the audiologists about the program routine and after the hearing screening was performed, they received a written result of the test.
Figure 2:
Figure 3:
Results: From the 4196 babies tested, 4123 (98.2%) had a normal test and 73 (1.8%) failed at the first stage screening. The follow up was done in 60 (82%) of those 73 babies and 10 (2.3--1000 live births) had a confirmed hearing loss, 3 of which without any hearing risk factors.
Figure 4: Results of screening
3. The Future
Health professionals in Brazil have a new challenge– the implementation of Universal Newborn Hearing Screening. Our goal of detection, diagnosis and intervention with hearing impaired children before the age of 6 months has not been achieved yet. Education, information and awareness about the need of early diagnosis and intervention is still necessary and mandatory in order to increase the number of programs in hospitals and maternities involving all the newborns and not only high-risk ones. We believe that the first step was already taken... But we still have a long way to go!!
4. References and Readings
- AMERICAN ACADEMY OF PEDIATRICS, Task Force on Newborn and Infant Hearing, Pediatrics Vol. 103, No. 2 : 527-530, February, 1999.
- APPUZZO,ML & YOSHINAGA-ITANO,C, Early Identification of Infants with Significant Hearing Loss and the Minnesota Child Development Inventory, Seminars in Hearing, Vol. 16, No. 2 : 124-139, may, 1995
- Chapchap MJ and Segre CM. Universal newborn hearing screening and transient evoked otoacoustic emission: new concepts in Brazil. Scand Audiol Suppl, 2001, (53) 33-6
- Comitê Brasileiro sobre Perdas Auditivas Na Infância - Recomendação 01--99. Jornal do CFFa 2000; 5: 3-7.
- DOWNS, MP, The Case for Detection and Intervention at Birth, Seminars in Hearing, Vol. 15, No. 2 :70-83, may, 1994.
- GRANDORI, F & LUTMAN,M, The European Consensus Development Conference on Neonatal Hearing Screening – Milan, May 15-16, 1998, Am J Audiol, 8(1) : 19-20, Jun, 1999.
- JOINT COMMITTEE ON INFANT HEARING, Year 2000 Position Statement: Principles & Guidelines for Early Hearing Detection & Intervention Programs, Audiology Today, Special Issue : 1-23, August, 2000.
- NATIONAL INSTITUTES OF HEALTH, Early identification of Hearing Impairment in Infants and Young Children – National Institutes of Health Consensus Development Conference Statement, 1-3; 11(1) :1-24, march, 1993.
- PARVING, A, The need for Universal Neonatal hearing screening – some aspects of epidemiology and identification, Acta Paediatr Suppl, 88(432) : 69-72, dec, 1999.
- SPIVAK,LG, Universal Newborn Hearing Screening, New York, Thieme, 1998.