The Effect of Universal Newborn Hearing Screening on Spoken Language after Cochlear Implantation.

Abstract

The universal newborn hearing screening (UNHS) was fully implemented across New Zealand by 2010 to improve outcomes for children with prelingual deafness. A previous audit undertaken by our center, the Southern Cochlear Implant Programme (SCIP), demonstrated that UNHS has significantly reduced the time to referral and surgery for cochlear implants in these children. This study aims to evaluate the relationship between earlier implantation and language development, the time taken to achieve age-appropriate language, and the effect of socioeconomic status on language skills. This is a retrospective cohort study comparing prelingual children with severe to profound bilateral hearing loss who underwent cochlear implantation in SCIP before and after the introduction of the UNHS. The language outcomes were assessed using the Preschool Language Scale and/or the Peabody Picture Vocabulary Test. For the purpose of our study, the standard scores of these tests were expressed as global language scores (GLS). GLSs between 85 and 115 are considered within normal range for age. The socioeconomic status was categorized based on the New Zealand Index of Deprivation (NZDep). Children in the post-UNHS group (46/95 children) were referred to SCIP and received CI at a significantly earlier age (mean = 7 vs 20 mo, p = 8.95E-10, and mean = 13 vs. 24.7 mo, p = 1.43E-07). At 2 years postimplantation, the GLS was significantly higher in the post-UNHS group (mean scores = 93.3 vs. 79.1, p = 0.0213). The scores remained statistically higher in the post-UNHS group when assessed at 3 and 4 years postimplantation. At 2, 3, and 4 years postimplantation, there is a significant linear decrease in GLS with increasing age at cochlear implantation. We found no correlation between NZDep and GLS. Children identified through UNHS have the advantage of earlier diagnosis, earlier hearing intervention, and longer duration with the implants, and they can achieve age-appropriate spoken language after 2 years of implantation.