Definitions

Importance of detection

Methods of assessment

Statewide Infant Screening Programme-Hearing (SWISH)

A 3 frequency average hearing level of 40dB or worse in the better ear.*

* Australian Working Party Report, G. Birtles et al. July 1998

Because this loss:

may lead to significant educational and psychosocial delay

can practically be detected in young children in the absence of an internationally agreed

standard, is commonly used in research

shaded region shows the level and frequency of average speech

Frequency in Hz

Hearing level in dB

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Frequency in Hz

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Frequency in Hz

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Frequency in Hz

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Frequency in Hz

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Estimated incidence in Australia is 20/10,000 live birthsCompare this with other currently screened disorders.

Disorder Incidence/10,000

Galactosaemia 0.3

PKU 1.0

Hypothyroidism 2.9

Cystic Fibrosis 4.0

cystic fibrosis 35 hypothyroidism 25 PKU 1 all others 14

deafness 174

Risk factors for hearing impairment:

low birthweight/ preterm

positive family history

craniofacial anomaly

meningitis

ototoxic medication use

congenital infection

BUT, 50% of hearing impaired do not have risk factors.

Language of Early and Later identified Children with Hearing Loss

Christine Yoshinaga-Itano, Colorado

72identified <6/12

78identified>6/12

150 dea f in fan ts

Aiding and early intervention within 2/12

Language &

cognition assessed

Total language quotient in early compared to late treated groups*

93 9491 90 91

7772

6873

84

40

50

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100

mild mod mod-severe severe profound

<6/12

>6/12

level of hearing loss (normal cognition)

MCDI total language quotient

*Yoshinaga-Itano

Discrepancy between cognitive quotient and language quotient by age of identification for

children with normal cognition*

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receptive expressive total

Language scale

Mea

n d

iffe

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ce s

core

(CQ

-LQ

) <6/12>6/12

*Yoshinaga-Itano

Mean total language scores at 31-36months by age of identification of hearing loss*

20 30 40 50 60 70 80 90 100 110

mean language quotient

earlier identification/normal cognition

later identification/normal cognition

earlier identification/low cognition

later identification/low cognition

* Yoshinaga-Itano

Conclusion: from Yoshinaga-Itano

There appears to be a critical time at around 6 months of age for identification and remediation of hearing impairment.

2nd C. Yoshinaga-Itano study J.Perinatol Dec2000

By 1997 26/36 birthing U.S. hospitals screening

25 matched pairs of children with hearing impairment born in screening or nonscreening hospitals

Assessed language outcome (quotient>80 vs<70)

If born in a screening hospital have 2½ x chance of having the higher language score.

Other considerations

Improved hearing usually results in: Increased academic achievement

Decreased costs of education and training

Income proportional to language skills

and Parent-child relationships improved if parents know

about hearing impairment from the outset

Distraction techniques Otoacoustic Emissions (OAE) Auditory Brainstem Response Audiometry

(ABR) combinations of the above

VICS study child health nurses & distraction

Marked increase in earlier detection(<12m)

BUT still many late (3-4yrs) diagnoses

Raised community awareness

dearer than newborn screening(UK study)

Tests pathway to the level of the cochlea

Cochlear hair cells emit sounds spontaneously, but usually tested in response to an input signal

Not of great value in the first 48 hours after birth due to ear canal debris

Probe containing an earphone and microphone placed in the infant’s ear.

Sounds measured in ear canal after click stimulus

Quiet room necessary

Quick and simple to perform

Causes of hearing loss beyond the cochlea are missed

Tests auditory pathways to brainstem Responses elicitable by about 34 weeks

gestation Can be done immediately after birth

(Wave IV-V)

Auditory

Pathways

in BAER

External cochlear nerve (Wave I)

(Wave I I)

(Wave III)

(end of wave V)

BAER waveform

AABR (Automated ABR) is used

False positive very low

Neonatal high risk screens -sensitivity (100%) -specificity (94-100%)

AABR takes longer than OAE

AABR screening

*Finitzo, Albright & O’Neal, 1998

1) Birth admission screen

2) Follow Up & diagnosis

3) Intervention services

Breakdown at any stage jeopardizes the entire effort

Expense Repeat tests require extra time & resources

from parents Parental anxiety Early discharge & rural births Resources for diagnosis and management Non-compliance with screening Cultural concerns

General Public

Antenatal education

Primary health providers

Audiologists

Huge role for the family doctor

Ongoing role once the diagnostic test has proven hearing impairment

Initial intensity of grieving may not be related to degree or type of hearing loss

Parents may experience depression, but

report that the benefit of early-identification is that they bond with their newborn as a child with a hearing loss and don’t have to change their mind about who their baby is.

All babies born in public hospitals in NSW

In CSAHS all babies either at RPAH or Canterbury

Each area will have dedicated screeners (3 in CSAHS)

Each area will have a co-ordinator

All hospitals with >400 births per year

Prior to discharge at the bedside

Clinics on Monday morning at Canterbury and Tuesday at RPA if missed

Automated Auditory Brainstem Responses

(AABR)

Birth admission screen

pass refer 2nd screen

pass

refer

Diagnostic testing - Sydney Children’s Hospital or Children’s at Westmead

pass (false positive screen)

Counselling, aids, intervention services, follow up and support