Controlled trial of universal neonatal screening for early identification of permanent childhood hearing impairment. Wessex Universal Neonatal Hearing Screening Trial Group

Abstract

Background: Congenital permanent childhood hearing impairment (PCHI) impairs communication skills and, possibly, mental health and employment prospects. Management within 1 year of birth can alleviate most of its adverse effects. Neonatal screening for this disorder is feasible but its benefit for all babies is disputed. We investigated whether neonatal screening of all babies born in hospital, in addition to the standard health visitor distraction test, would increase the rates of early referral, confirmation, and management.

Methods: Between 1993 and 1996, two teams of four part-time testers and equipment moved between two pairs of hospitals to achieve four periods with neonatal screening and four without neonatal screening, each of 4-6 months' duration. Babies did or did not undergo neonatal screening dependent on during which periods they were born. We used a transient evoked otoacoustic emissions test and, in babies who failed this test, an automated auditory brainstem response test on the same day. We referred babies with positive results for audiological assessment.

Findings: 53,781 babies were included in the trial, and 25,609 were born during periods with neonatal screening. Neonatal screening achieved 87% coverage of births, with a false-alarm rate of 1.5%, and an overall yield of 90 cases of bilateral PCHI of 40 dB or more relative to hearing threshold level per 100,000 target population, equivalent to 80% of the expected prevalence of the disorder in the population. 71 more babies with moderate or severe PCHI per 100,000 target population were referred before age 6 months during periods with neonatal screening than during periods without. Early confirmation and management of PCHI were significantly increased. The rate of false-negative results from neonatal screening was significantly lower than that for the distraction test (4 vs 27% p=0.041).

Interpretation: Neonatal screening is effective in identification of congenital PCHI early and may be particularly useful for babies with moderate and severe PCHI for whom early management may have the most benefit.