Levels of evidence: universal newborn hearing screening (UNHS) and early hearing detection and intervention systems (EHDI).

UNLABELLED Levels of evidence differ according to the audience addressed. Implementation of universal newborn hearing screening requires responses to a complex myriad of diverse groups: the general public, families with children who are deaf or hard of hearing, the deaf and hard of hearing communities, hospital administrators, physicians (pediatricians, general practitioners, ear nose and throat physicians, geneticists), managed care, Medicaid, insurance agencies, and politicians. The level of evidence required by medical/health agencies and task forces may differ from the levels of evidence available in education and intervention. Issues related to the low incidence of the disability, the lack of a normal distribution within the disability study, the obstacles to random assignment to treatment, and designs that include a control group with "no treatment" have implications legally and ethically for the professional providing services to families and children who are deaf or hard of hearing. This session will discuss issues related to "convenience samples," number of subjects included in research studies, and the population required to obtain a large enough sample of children with low-incidence disabilities. The level of evidence required to demonstrate sensitive periods of development, which are a critical element for justification of implementing a universal newborn hearing screening includes both behavioral and neurological information. Sensitive periods may have different duration for different aspects of development, such as social-emotional development, auditory and speech development, or language development. Further complicating the question of sensitive periods of development are the distinct possibility that different sensitive periods exist for development of age-level vocabulary, for establishing English phonology, or for mastering English syntax. Research outcomes provide evidence that age of identification of hearing loss is reduced, that age of intervention initiation is lowered, and that the outcomes of intervention are better because of the establishment of a screening program. Most professionals in communication disorders believe that screening is not the actual cause of better developmental outcomes but that the age when children begin to have access to language and communication and the characteristics of the intervention are the primary cause of better outcomes. Screening is the avenue through which access to quality intervention is made available. The research still remains at an infant level of development such that there is very little evidence for the efficacy of specific characteristics of the intervention provided. LEARNING OUTCOMES (1) The learner will be able to identify the obstacles in conducting research on the effectiveness of intervention of children identified through universal newborn hearing screening programs. (2) The learner will be able to identify the type of research on developmental outcomes of children with early-identified hearing loss.