Hearing tests in newborns: Are there advantages?

Together with researchers from England and the German Cochrane Center, researchers at the Institute for Quality and Efficiency in Health Care (IQWiG, Germany) looked into the effects of routine hearing screening in all newborns. In particular, they wanted to know

• how many more hearing-impaired babies are diagnosed as a result of routine screening,
• whether earlier treatment of hearing problems in babies is more effective than later treatment in the short or long term, and
• whether the screening and any resulting treatments have a direct impact on the child’s personal and educational development, as well as on their quality of life.

Screening would be a good idea if, for instance, it turns out that children benefit from early treatment. If earlier treatment makes no difference, though, or is actually associated with particular risks, then screening wouldn’t be worthwhile.

The researchers looked for relevant studies in this area. The kinds of studies with the most reliable results are studies in which researchers are able to follow the development of two groups of children – one group which has been screened, and one group which has not – over a long period of time. The effects of the screening tests can then be determined by comparing the groups.

The researchers found two studies in which children had hearing screening in different geographical areas or at different times. One of the studies was carried out in England, and the other was carried out in the U.S. Four other studies compared the effects of early treatment for hearing problems with the effects of later treatment. But the quality of many of these studies wasn't good enough to reliably determine what can be expected from routine hearing screening.

There were only two studies on screening programs, and neither of them were randomized controlled trials (RCTs). RCTs are studies that provide the most reliable findings about the effectiveness of treatments and diagnostic tests. Four studies compared early treatment with later treatment. Together, these studies suggest that children with congenital (“at birth”) hearing loss could benefit from screening and an early diagnosis.

One of the screening programs was in the U.S. and one was in England. The studies and the screening programs were very different. But the research showed that hearing problems are usually diagnosed much sooner if newborns are routinely screened. For instance, the study in England found that hearing problems were detected within the first nine months of life

• in 3 out of 10 hearing-impaired children who didn't have a hearing test immediately after birth, and
• in 7 out of 10 hearing-impaired babies who had a hearing test immediately after birth.

In other words, the early hearing screening was able to detect the hearing impairment early in an extra 4 out of 10 affected children.

The research showed that children whose hearing impairment was diagnosed through screening have better early language development than children whose hearing impairment was diagnosed later. This was confirmed by the four studies in which children who were treated early were compared with children who were treated later. Different treatments were looked at, particularly patient education and the use of hearing aids. There hasn’t been enough research on the long-term effects of newborn hearing screening on other important areas of the child’s life, such as their development at school, psychological wellbeing and quality of life.

The researchers at IQWiG came to the following conclusion: Routine hearing screening in newborns can improve the chances of congenital hearing loss being diagnosed and treated earlier. This can improve early language and speech development in children who have hearing problems. But we can't know for certain what long-term effects this has on the children because there haven’t been enough good studies on how early diagnosis and early treatment affect the child's hearing impairment.