Now hear this. There are some experiments that you just don’t do. In the United States no researcher would suggest doing a clinical trial or other clinical intervention to compare the universal hearing programs for newborns to older approaches of screening infants exposed to certain drugs or who were born prematurely. It wouldn’t be considered ethical to experiment on babies.
Currently, more than 95 percent of all newborns born in the United States are screened for hearing loss shortly after birth. Recent data from the Centers for Disease Control and Prevention (CDC) demonstrate that 77% of children confirmed to have a permanent hearing loss were enrolled in intervention programs by six months of age. That’s important because infants who are identified and enrolled in appropriate treatment programs do better cognitively and socially. Universal newborn screening programs were implemented after statistical modeling suggested the long-term benefits of the programs. Some observers have suggested real-life evidence would be useful and this month, a study by Wake et al. (10.1542/peds.2015-1722) published in Pediatrics does just that.
These Australian researchers have evaluated an interesting natural experiment on differing practices for newborn hearing in two states – New South Wales and Victoria. (To help remind you of the geography, Sydney is located in New South Wales and Melbourne is in Victoria. Both states are major population areas in Australia.)
Between 2003 and 2005, the two states had differing screening policies to evaluate deafness in newborns, and the study examined how the different screening approaches did at detecting bilateral congenital hearing loss (>25 decibels in better ear).
New South Wales offered automated auditory brainstem response screening to the estimated 84,500 infants born each year, and babies who failed two successive screens were referred to diagnostic audiology. Victoria also used auditory brainstem response screening for all newborns admitted to the state’s four neonatal intensive care units (NICU) and associated special care nurseries .The NICU infants were offered the testing at discharge and 71% were tested. The failing infants were referred for diagnostic audiology All other Victoria newborns had a hearing risk factor assessment and behavioral hearing screening.
The authors report that children were diagnosed a mean of eight months earlier with universal screening compared to the risk-factor screening. The authors also reported that among children without intellectual disability, universal screening was associated with better outcomes in expressive language and receptive vocabulary.
The audible message is that universal newborn screening detects hearing loss earlier and that identified children do better at speaking and understanding what is said to them. Universal screening for hearing loss in newborns also produces economic savings. The National Center for Hearing Assessment and Management (NCHAM) reports that detecting and treating hearing loss at birth for one child saves $400,000 in special education costs by the time that child graduates from high school.1 Screening of a single newborn is estimated to cost $10 to $50 depending on the state program.
The Australian researchers have done a natural experiment evaluating different policies. They provide real-life support for policy decisions that had been based on decision modeling only.
1. National Council of State Legislatures. Newborn hearing screening laws. http://www.ncsl.org/research/health/newborn-hearing-screening-state-laws.aspx Assessed November 25, 2015.