The Longitudinal Outcomes of Children with Hearing Impairment (LOCHI) study: A brief overview of interim findings

One to two children in every thousand under the age of 3 have a permanent bilateral hearing loss of greater than 40 dB HL and are fitted with hearing aids (Ching, Oong, & Van Wanrooy, 2006). Permanent childhood hearing loss impacts negatively on the communicative, educational, and social developmental outcomes of children. Several retrospective studies have established an association between intervention before 6 or 9 months of age and better language skills measured at 3 and 5 years of age (Moeller, 2000; Yoshinaga-Itano, Sedey, Coulter, & Mehl, 1998). Despite the frequent citing of these studies as evidence in support of the effectiveness of early identification in improving outcomes for children with permanent bilateral hearing loss, the United States Preventative Task Force (USPSTF; Thompson et al., 2001) conducted a systematic review of evidence in 2001 and found that the “evidence to determine whether earlier treatment resulting from screening leads to clinically important improvement in speech and language ... is inconclusive because of the design limitations of existing studies” (reported in Helfand et al., 2001). More recent reviews (Nelson, Bougatsos, & Nygren, 2008; Wolff et al., 2009) revealed that the evidence on the efficacy of early intervention in improving language outcomes for children with permanent bilateral hearing loss is weak. In Australia newborn hearing screening is now at above 80% coverage in all states except for Victoria, with five states now screening more than 95% of newborns. Australian Hearing is the sole national service provider for all children diagnosed with permanent hearing loss. Several years ago, different Australian states were at different stages of implementing universal newborn hearing screening, and there was a narrow timeframe during which there were sufficiently large numbers of children who received early or later intervention from the same service provider (Australian Hearing) using consistent protocols. The National Acoustic Laboratories, the research arm of Australian Hearing, captured this unique research opportunity in 2005 to conduct a direct prospective comparison of outcomes for children who received early or later intervention. The aims of this study are (a) to establish an evidence base for the development of speech, language, functional and psychosocial skills, and educational attainment of children with hearing aids and/or cochlear implants, and (b) to identify the extent to which outcomes in each dimension are affected by a range of child- , family- and device-related factors, including age of intervention.