A test commonly used to screen newborns for hearing problems may give false positives in as many as 35% of cases, a new University of Michigan (U-M) study has found.

Besides causing new parents to worry needlessly about their child's hearing, the technique may also lead to more costs in the long run for follow-up tests.

The new finding was published in the December issue of the American Journal of Audiology.

The U-M study looked at 596 babies born at the U-M Health System who had no hearing-loss risk factors. All children were given both a "distortion product otoacoustic emission" (DPOAE) test, and an auditory brain stem response (ABR) test. The DPOAE test is commonly used in many hospitals around the country.

All the infants passed the ABR test in both ears. But although none of the infants actually had hearing problems, the first round of DPOAE tests performed suggested that 35% of the babies tested would need to return for follow-up testing to rule out hearing loss. Even when lower testing standards were used, 11% of infants failed the DPOAE test.

"If we're going to do universal newborn screening, we should do it right," said researcher Paul Kileny, Ph.D., director of Audiology and Electrophysiology and professor in the Department of Otolaryngology. "These data show that ABR is more accurate and results in far fewer false positives. Why have parents on pins and needles for weeks when you can clear their normal-hearing baby on day one?"

Many hospitals do not have the ABR test equipment because it is more costly that the DPOAE equipment.

"Hospitals should consider this (the superiority of ABR) when choosing their preferred testing method," stated Dr. Kileny, "and not just the up-front cost of the equipment. The potential cost of false positives may be much greater, because of the need to re-test relatively large numbers of babies."

SOURCES: "Common Hearing Test for Newborns May be Wrong Up to a Third of the Time," University of Michigan, December 5, 2000.