In contrast to the recommendations of the Joint Committee on Infant Hearing, neonatal hearing screening programs are still not universally available, and many countries implement elective screening in high-risk newborns.
To assess the failure rates of neonates in hearing screening and the relative importance of risk factors for hearing impairment, both in neonatal intensive care units and in well-baby nursery neonates. The impact on cost-effectiveness is also evaluated.
In the current study, 25,288 newborns were assessed; 23,574 were full-term newborns in the well-baby nursery and 1,714 neonates were in neonatal intensive care units.
All neonates had a general examination (including assessment for congenital anomalies and related history) and were assessed using transient evoked otoacoustic emissions. All newborns were older than 36 weeks at examination and thus had reliable transient evoked otoacoustic emissions.
From the 23,574 full-term neonates in the well-baby nursery, 23,123 (98.1%) passed the test and 451 failed (1.9%). Fifty-three of the 23,574 neonates (0.2%) had a risk factor for hearing impairment; 44 (83%) passed the test and 9 failed (17%). Family history of congenital hearing loss and congenital anomalies were the most frequent risk factors for hearing loss. From the 1,714 neonates in neonatal intensive care units, 1,590 (93%) passed the test and 124 failed (7%). Two hundred thirty-two of the 1,714 neonates (14%) had a risk factor for hearing impairment; 205 (88%) passed the test and 27 failed (12%). In neonatal intensive care unit neonates, toxic levels of ototoxic drugs, mechanical ventilation for more than 24 hours, prematurity, and low birth weight were the most frequent risk factors for hearing loss. Congenital anomalies/syndromes were the most important risk factors for failing screening in both the neonatal intensive care unit and the well-baby nursery, as they showed the highest risk of failing hearing screening. The second most important factor in neonatal intensive care unit newborns was low birth weight, and the third was prematurity in relation to the possibility of failing hearing screening.
The present study found 575 neonates failing hearing screening of 25,288 tested newborns (2.3%). The fact that 78% of newborns who failed hearing screening were in the well-baby nurseries further supports the necessity of universal hearing screening instead of selective screening in neonatal intensive care units, even with the obvious impact on cost-effectiveness. Even if limited funding lead to selective screening in neonatal intensive care units, this should not be applied to high-risk newborns but to all neonatal intensive care unit neonates. Continuous assessment of risk factors and the related possibility of failing hearing screening are of paramount importance in designing hearing screening programs and refining the respective criteria.