Universal Newborn Hearing Screening

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Original Research

Universal Newborn Hearing Screening

J Fam Pract. 2000 November;49(11):1012-1016

References

1. National Institutes of Health. Early identification of hearing loss in infants and young children. NIH consensus statement 1993;11:1-24.

2. American Academy of Pediatrics Joint Committee on Infant Hearing 1994 position statement. Pediatrics 1995;95:152-56.

3. Bess FH, Paradise JL. Universal screening for infant hearing impairment: not simple, not risk free, not necessarily beneficial, and not presently justified. Pediatrics 1994;93:330-34.

4. Paradise J. Universal hearing screening: should we leap before we look? Pediatrics 1999;103:670-72.

5. Huynh MT, Pollack RA, Cunningham RA. Universal newborn hearing screening: feasibility in a community hospital. J Fam Pract 1996;42:487-90.

6. Mason JA, Hermann KR. Universal infant hearing screening by automated brainstem response measurement. Pediatrics 1998;101:221-28.

7. Maxon AB, White KR, Behrens TR, Vohr BR. Referral rates and cost efficiency in a universal newborn hearing screening program using transient evoked otoacoustic emissions. J Am Acad Audiol 1995;6:271-77.

8. Mehl AL, Thompson V. Newborn hearing screening: the great omission. Pediatrics 1998;101:E4.-

9. Vohr BR, Carty LM, Moore PE, Letourneau K. The Rhode Island hearing assessment program: experience with statewide hearing screening (1993-1996). J Pediatrics 1998;133:353-57.

10. Johnson JL, et al. Implementing a statewide system of services for infants and toddlers with hearing disabilities. Semin Hearing 1993;14:105-19.

11. Apuzzo ML, Yoshinaga-Itano C. Early identification of infants with significant hearing loss and the Minnesota Child Development Inventory. Semin Hearing 1995;124-39.

12. Yoshinaga-Itano C, Sedey AL, Coulter BA, Mehl AL. Language of early-and later-identified children with hearing loss. Pediatrics 1998;102:1161-71.

13. Cundall J. Universal newborn hearing screening in Tennessee. Tennessee Med 1997;370-71.

14. Osterhammel PA, Rasmussen AN. Distortion product otoacoustic emissions basic properties and clinical aspects. Hearing J 1992;45:38-41.

15. Psarommatis IM, Tsakanikos MD, Kontorgianni AD, Ntouniadakis DE, Apostolopoulos NK. Profound hearing loss and presence of click-evoked otoacoustic emissions in the neonate. Int J Pediatr Otorhinolaryngol 1997;39:237-43.

16. Ochi A, Yasuhara A, Kobayashi Y. Comparison of distortion product otoacoustic emissions with auditory brain-stem response for clinical use in neonatal intensive care unit. electroencephalography and clinical neuropsyciology 1998;108:577-83.

17. Doyle KJ, Burggraaff B, Fujikawa S, Kim J. Newborn hearing screening by otoacoustic emissions and automated auditory brainstem response. Int J Pediatr Otorhinolaryngol 1997;41:111-19.

18. Time. January 1, 2000;117.-

19. Frame PS, Carlson SJ. A critical review of periodic health screening using specific screening criteria part 1: selected diseases of the respiratory, cardiovascular, and central nervous system. J Fam Pract 1975;2:29-36.

20. White KR, Vohr BR, Behrens TR. Universal newborn hearing screening using transient evoked otoacoustic emissions: results of the Rhode Island Hearing Assessment Project. Semin Hearing 1993;14:18-29.

21. Lutman ME, Davis AC, Fortnum HM, Wood S. Field sensitivity of targeted neonatal hearing screening by transient evoked otoacoustic emissions. Ear Hear 1997;18:265-76.

22. Fowler KB, et al. Newborn hearing screening: will children with hearing loss caused by congenital cytomegalovirus infection be missed? J Pediatr 1999;135:60-64.

23. Personal conversation with Nancy Pajka. January 2000.

Discussion

Recent advances in technology have provided the means to screen newborns and infants for hearing deficits. The 2 most commonly used technologies are AABRs and otoacoustic emissions. Otoacoustic emissions were first described by Kemp in 1978. The cochlear basal membrane vibrates when stimulated by sound, and this vibration sends a retrograde wave back through the cochlear fluid that ultimately vibrates the eardrum, producing a sound wave that can be detected by a microphone at the external ear. DPOAE are produced by stimulating the cochlea with a series of 2 specific frequencies, resulting in a single predictable frequency response.¹⁴ Transient evoked otoacoustic emissions, an alternative to DPOAE, are evoked by a click that results in the emission of several frequencies at the same time. AABRs are also used in screening programs, with the advantage of testing both the cochlea and retrocochlear functions. However, the majority of infants with hearing loss have cochlear deficits.¹⁵ Otoacoustic emission testing can be done with the infant awake, feeding, or sucking on a pacifier. AABR requires the infant to be asleep. Currently, it is unknown which screening test or combination of tests is best. A few studies have compared various screening methods, but no consensus has been reached.^16,17 Twenty-two states currently mandate some form of newborn universal hearing screening.¹⁸

We looked at the feasibility of universal infant hearing screening and whether it meets the criteria for screening tests discussed by Frame and coworkers.¹⁹

Disease Recognition

Is there an identifiable disease? Yes. The NIH consensus statement1 identified the risk of hearing loss at 1 per 1000 births. Other studies have found a base rate of from 2 per 1000 to as high as 5 to 9.75 per 1000 in high-risk infants.^5-8,20 Without universal screening, the average age at which a deaf child is identified is 2.5 years.¹ Typically, these children are tested because of a delay in language and speech skills. The goal of any screening program is to identify and effectively treat a disease in the asymptomatic stage.¹⁹ Unfortunately, not all infant hearing loss is identifiable at birth. Approximately 20% to 30% of children develop their deafness in the first few months of life.¹ Because of this, health care systems must be vigilant and have a low threshold for repeat screening in older infants. Assuming a hearing loss incidence of 1 per 1000, a birthrate of 4 million per year, and the ability to detect 80% of affected newborns, 3200 infants per year could be diagnosed with hearing loss.

Early Identification

Does early identification and intervention while the infant is asymptomatic improve outcomes? The experts who developed the NIH consensus statement¹ stated that early intervention probably does improve outcomes. When this statement was made, however, there had not been adequate studies showing improved outcomes with intervention by the age of 6 months. Since then there have been 2 studies showing significant improvement in expressive and receptive language skills in infants diagnosed and treated before the age of 6 months. Apuzzo and Yoshinaga-Itano¹¹ showed significant improvement in language skills in study of a subset of infants diagnosed before the age of 2 months. Their study included 63 infants, and only those with severe hearing loss (23 infants) had a statistically significant improvement in outcomes. Infants with profound, mild, and mild-to-moderate hearing loss did not have significant improvement. A later study by Yoshinaga and colleagues¹² revealed significant improvement in all categories of hearing loss when diagnosed and treated before the age of 6 months. Of the 150 infants in that study, 72 were diagnosed before the age of 6 months, and 78 were diagnosed after the age of 6 months. The early-identified infants had significantly better language skills regardless of the degree of hearing loss, socioeconomic class, and level of cognitive skills. Early diagnosis needs to be coupled with an effective intervention program.¹ The intervention should be multidisciplinary and include a physician experienced in otologic disorders, an audiologist with experience in infants and hearing augmentation, a speech and language pathologist, a sign language specialist, and family support services.²

Sensitivity and Specificity

What are the false-negative and false-positive rates of the test? In Rhode Island, universal screening began in 1991 using otoacoustic emission testing. In an article by Vohr and coworkers⁹ only 5 infants with sensorineural hearing loss had passed the initial screen (false-negatives). Of the 47,257 infants screened there were 106 true-positives, so the sensitivity was 95%. Mehl and Thompson8 reported on the Colorado screening program that used either otoacoustic emissions or AABR. There were no false-negatives, and 41,796 infants were screened. At the other end of the spectrum, Lutman and coworkers²¹ found a false-negative rate of 20% in high-risk infants screened with otoacoustic testing. The majority of these infants were from the newborn intensive care unit and thus were at higher risk for central nervous system disease (eg, kernicterus, cytomegalovirus) and associated hearing loss. Otoacoustic emissions are normal in infants with hearing loss secondary to central lesions. This may account for some of the false-negative tests in that study.^15,22 Infants with known central nervous system disease should probably be evaluated with auditory brain response testing. There has not been a controlled long-term study specifically evaluating the actual false-negative rate in a universal screening program. In the Rhode Island and Colorado groups the false-negative rate appears to be very low. Our study was not designed to determine a false-negative rate. The large number of required subjects (50,000)²¹ and the length of time required to do a meaningful assessment of the false-negative rate were beyond the scope of our study.