Efficacy of automated auditory brainstem response hearing screening in very preterm newborns

Abstract

Objective: To investigate the efficacy of an automated auditory brainstem response (AABR) hearing screening method in very preterm newborns in the neonatal intensive care setting.

Study design: In this prospective cohort study, 90 consecutive preterm newborns (<32 weeks' gestational age) had AABR hearing screening weekly from birth until a bilateral pass result was obtained. If the newborn had a unilateral pass result, AABR screening was repeated in the same week. Data were analyzed by using the Kaplan-Meier survival function technique, resulting in a cumulative pass rate curve for postmenstrual age. Cox's regression method was used to analyze the effect of co-variables, such as sex and growth restriction, on pass rates.

Results: Median gestational age was 29.5 weeks (range, 25.3-31.9 weeks), and median birth weight was 1115 g (range, 600-1960 g). Mean age was 6.2 days (SD 4.3) at first test, 15.7 (SD 8.1) at second test, and 21.4 (SD 8.6) at third test. Eighty percent (CI: 70.2%-89.8%) of the newborns passed at 30.3 weeks' postmenstrual age, 90% (CI: 83.6%-96.4%) passed at 31.2 weeks, and 100% passed at 34 weeks' postmenstrual age. The attainment of these pass rates correlated to postmenstrual age was not significantly influenced by sex, growth restriction, or gestational age at birth. Postnatal pass rates (in days) were strongly influenced by gestational age.

Conclusion: AABR pass rates of >80% can be obtained from 30 weeks' postmenstrual age. Therefore AABR neonatal hearing screening can be used before discharge from a neonatal intensive care unit.