Mass newborn screening for hearing impairment.

ABSTRACT

Significant hearing impairment is common and impairs communication potential if not detected early. Babies born at the National University Hospital from March 1999 to February 2001 were screened at birth using the strategy of measuring Transient Evoked Oto Acoustic Emissions with the ILO 88 Otodynamics Echoport. The screening was conducted within 24 hours of birth in the majority of patients. Those testing positive were re-screened at about 2 weeks and at 6 weeks if still testing positive. Those who tested positive at 6 weeks were referred to Otolaryngology for formal evaluation of hearing. A total screening rate of 97.2% (4,387 out of 4,514 livebirths) was achieved. Of the 312 testing positive at 6 weeks, 8 were subsequently proven to have significant hearing impairment. Four of them required binaural amplification, giving a 1 in 1,096 incidence of severe hearing impairment. A specificity, positive predictive value and sensitivity of 93%, 26% and 100% respectively were obtained. In all but one, the diagnosis was made by 7 months of age and interventions set in place within 2 months of diagnosis. The screening strategy was reliable and sensitive. A strategy to reduce the high false positive rate needs to be developed.