By Shereen Lehman
NEW YORK (Reuters Health) - Teenagers whose hearing loss was detected very early in infancy had better reading comprehension than their hearing-impaired peers who were diagnosed later, according to a new study from the UK.
The results suggest that detecting hearing loss, and intervening at a critical early stage, can make a lifelong difference in development, researchers said.
That possibility strengthens the case for implementing universal newborn hearing screening programs in countries that have not adopted such programs as national policy, the study authors write in the Archives of Disease in Childhood.
“Permanent bilateral childhood impairment is the commonest congenital impairment and affects considerably more than one in 1,000 newborns,” Dr. Colin Kennedy, the study’s senior author, told Reuters Health in an email.
“There is a sensitive period in early infancy when if the brain receives the right input, language will develop in a way that it rarely does if the right input is not received until later in life,” said Kennedy, a pediatric neurologist at the University of Southampton and University Hospital Southampton NHS Foundation Trust.
Kennedy said there is an effective and very acceptable screening test that can be done on newborn babies.
“If this picks up permanent deafness early, this will greatly improve the babies’ chances of learning to read and communicate as well as a child with normal hearing,” Kennedy said.
Universal newborn screening programs have been implemented in the UK and Germany. About 90 percent of babies born in the U.S. are screened.
For the new study, Kennedy’s team followed up with 76 teenagers with permanent hearing impairment whose reading skills had been assessed between the ages of 6 and 10, and then again nine years later.
The researchers compared the reading comprehension scores of 35 teens with hearing loss that had been confirmed before the age of nine months to 41 teens whose hearing loss was diagnosed after nine months of age.
On average, the teens diagnosed before the age of nine months had significantly higher reading comprehension scores than their counterparts. In fact, the gap had widened since the children were in primary school.
The difference was largely a result of reading skills having worsened among the teens whose hearing loss was confirmed when they were older.
Dr. Nancy Young, who was not involved in the study, said it would have been helpful to also know when the children obtained effective interventions, such as hearing aids.
Young is a pediatric otolaryngologist with Lurie Children's Hospital of Chicago and the Northwestern University Feinberg School of Medicine.
“It may be, I suspect, that unless the families didn't follow through, they had access to hearing aids through the government-funded health system and therefore they were likely to have had an intervention in a reasonable timeframe,” she said.
Young said that children with permanent hearing loss can be fit with hearing aids within four to six weeks of birth, if they can be identified and get a confirmed diagnosis.
“If you get access to good services and you get accurate testing, it's possible to get kids amplification very, very young,” she said.
Young noted that newborn hearing screening occurs throughout every state in U.S. “We have achieved a high success in newborn screening.”
However, getting access to both the diagnostic testing and then to hearing aids and cochlear implants in particular can be problematic, Young said.
“It may not be covered, or well covered, by insurance,” Young said. “If the child is funded through public aid, for instance, there may not be providers in the area that will dispense hearing aids.”
Young also noted that in the study, children whose parents were not English-speaking were more likely to be in the group whose hearing loss was identified later.
“That is something that I see in my clinical practice,” she said. Such children are “both identified later and often have a later intervention because there are often more barriers for these families.”
SOURCE: http://bmj.co/1vfyKJR Archives of Disease in Childhood, online November 26, 2014.