Abstract:
OBJECTIVE : Postnatal visits at community-based midwife obstetric units (MOUs) have been proposed as
an alternative primary healthcare screening platform in South Africa. This study evaluated the outcomes
of distortion product otoacoustic emissions (DPOAEs) and automated auditory brainstem response
(AABR) screening conducted by a dedicated non-professional screener at a community-based MOU in
the Western Cape, South Africa.
METHODS : Universal newborn hearing screening (UNHS) at a community-based MOU was evaluated over
a 16-month period. A dedicated non-professional screener was trained to follow a two-stage screening
protocol targeting bilateral hearing loss. A two group comparative design was used alternating AABR
(Maico MB11 BERAphoneTM) and DPOAE (Bio-logic AuDX I) technology on a daily basis. Infants referring
the initial screen received a follow-up appointment in two days’ time and were rescreened with the same
technology used at their first screen. Those referring the second stage were booked for diagnostic
assessments.
RESULTS : 7452 infants were screened including 47.9% (n = 3573) with DPOAE and 52.1% (n = 3879) with
AABR technology. Mean age at first stage screen was 6.1 days. The initial bilateral referral rate was
significantly lower for AABR (4.6%) compared to DPOAE (7.0%) and dropped to 0.3% and 0.7% respectively
following the second stage screenings. First rescreen and initial diagnostic follow-up rates of 90% and
92.3% were obtained for the DPOAE group and 86.6% and 90% for the AABR group. Follow-up rates
showed no significant difference between technology groups. Diagnostic assessment revealed a higher
prevalence rate for bilateral SNHL among the AABR group (1/1000) compared to the DPOAE group (0.3/
1000). Screening technology had no significant influence on daily screening capacity (23 AABR/day;
24 DPOAE/day).
CONCLUSIONS : Postnatal visits at community-based MOUs create a useful platform for hearing screening
and follow-up. AABR technology with negligible disposable costs provides opportunity for AABR
screening to be utilised in community-based programmes. AABR screening offers lower initial referral
rates and a higher true positive rate compared to DPOAE.
