Children with Mild and Unilateral Hearing Impairment Current management and outcome measures Kirsti...

Children with Mild and Unilateral Hearing Impairment

Current management and outcome measures

Kirsti Reeve Ph.D.Developmental Disabilities InstituteWayne State University, Detroit MI

EDHI Feb 2004

Overview

Current management for children with mild and unilateral hearing impairment (HI)

Outcome measures:Speech and languageCognition

Why these populations? Very little known about management or

outcomes for mild or unilateral HI NHSP offers the potential for early

identification There is strong evidence that early

identification gives improved outcomes in moderate and greater HI populations

Need to ascertain whether it would be appropriate for these groups

Study overview

Two separate studiesQuestionnaire survey to audiologists

investigating management optionsOutcomes study

Obtained epidemiological data Assessed impact of HI quality of life Assessed impact of HI on speech, language &

cognition

Current management:options for children with mild or unilateral hearing impairment

Why assess service provision?

Areas of uncertaintyNumbers of children being identifiedAge of identificationManagement options for these groupsLevel at which to provide hearing aids

How was it done?

Single page questionnaire survey Sent out to 131 professionals

throughout the UK 1 reminder 56 responses (43%)

Results

Information on the mild and unilateral cases seen

Management offered to those cases

Results

Information on the mild and unilateral cases seen

Management offered to those cases

Numbers of children with bilateral mild impairment

Defined as 20-40dBHL permanent

sensorineural loss

Comprise 8% of total caseload

Range seen from 0 to 300 (mean of 25)

Estimated total number seen by 56

clinicians: 1220

Numbers of children with unilateral hearing impairment

Defined as permanent sensorineural loss in one ear only.

Comprise 4% of total caseload

Range seen from 0 to 40 (mean of 9)

Estimated total number seen by 56 clinicians: 443

Numbers of children seen

0

5

10

15

20

25

0 1-5 6-10 11-15 16-20 21-25 26-30 31-35 36+

Numbers

N

Mild

Unilateral

Numbers found Literature estimates prevalence figures at:

between 0.5-5.2% for unilateral impairment Between 1 and 5.4% for mild impairment

“It is well recognized that an inverse relationship exists between the prevalence and degree of hearing loss” – Bess 1984

The low percentage as ascertained by this questionnaire would imply that large numbers of these populations are not receiving audiological management

Age of Referral

0

5

10

15

20

25

30

35

0-6 months 6-12 months 1-3 years 4-6 years 6 years +

Age

N

Mild

Unilateral

Age of referral, data from Trent Region(Mild n=50, Unilateral = 30)

percentiles

Age in months

X

,

X

X

X

X

X

,

,

,

'

)

100

90

80

70

60

50

40

30

20

10

00 10 20 30 40 50 60 70 80 90 100 110 120 130 140

ModerateAll TrentMildUnilateral

X

Age of referral

Age of referral is late for both groups of children when compared with Trent data

Children with unilateral impairment identified significantly later than children with mild impairment

Modal age of between 4 and 6 years suggests that the school entry is a factor leading to identification

Results

Information on the mild and unilateral cases seen

Management offered to those cases

Management

0 10 20 30 40 50

Aid

Advice

Refer

Review

Speech Therapy

None/Discharge

Op

tio

ns

Frequency

Unilateral

Mild

Management

Most frequent options are review and advice

Children with mild HI are significantly more

likely to be offered:Hearing Aids (p=0.0005)Speech Therapy (p=0.003)Referral to other professional (p=0.022)

Provision of aids

Uncertainty among professionals on whether to aid mild HI

Level below which you would not consider providing aids: 25dBHL (range from 15 - 35dBHL)

Level above which you would definitely provide aids: 40dBHL (range from 25 to 50dbHL)

Management conclusions

Mild and unilateral HI are under-represented in the caseload of this sample

These groups of children are identified later than children with more severe impairments

Management is still uncertain whether to provide aids and at what level for children with a bilateral mild impairment

Outcome Measures – Language and Cognition

Hypotheses

Language is likely to be affected to some degree by a mild or unilateral hearing impairment

There will be a positive relationship between language scores, non-word repetition and verbal reasoning

Subjects 41 children from CHAC met study criteria:

Aged 6-11 Bilateral mild, or unilateral hearing impairment HI is sensorineural No associated syndromes, or other problems. No known learning or cognitive disabilities. English as first language

20 children agreed to participate though one child DNA’d twice, and was not followed up a third time.

Participants

8 mild 11 unilateral

6 mild, 3 moderate, 1 severe, 1 profound 5 left ear impaired, 6 right ear

5 girls, 14 boys Aged 6-11, average age 8yrs 3 months

Age of identification ranged from 9 months to 6 years 7 months (mean of 2 years 4 months)

Assessments

The session consisted of:Computer based test of sound lateralizationStandardised language assessment (CELF-3 UK)Children’s test of Non word RepetitionBAS verbal & non-verbal reasoning (IQ)

Most sessions lasted 90-120 mins including breaks.

Results

Language

Non-word repetition

Cognition

Results

Language

Non-word repetition

Cognition

Language testing - CELF 3 UK Standardised on UK population

Six subtests: 3 for receptive language (understanding)

Sentence Structure (aged 6-8) / Semantic Relationships (aged 9+)

Concepts and Directions Word Classes

3 for expressive language (speaking) Word Structure (6-8) / Sentence Assembly (9+) Formulated Sentences Recalling Sentences

171717N =

Total language score

Expressive language

Receptive language s

95

% C

I

110

100

90

80

70

Means of all language scoresStandardised Test: mean:100, sd:15

Receptive LanguageMean: 89.65,

sd 13.18

Expressive LanguageMean: 85.76,

sd 13.51

Total LanguageMean: 86.29,

sd 14.01

Total Language Scores for individual subjects

type of hearing impairment

2.52.01.51.0.5

Tota

l lan

guag

e sc

ore

120

110

100

90

80

70

60

Unilateral HI Mild HI

Speech & language results 1

Unilateral group - total language score mean of 91.78

Mild group - total language score mean of 80.12

With a linear regression, the difference in scores just misses significance (.089) - this could be due to the small sample size.

Speech & language results 2

Converting scores to age equivalent gives an average language delays of:6 months for children with a unilateral

impairment24 months for children with a mild impairment

Results

Language

Non-word repetition

Cognition

Children’s Test of Non-word Repetition Assesses phonological memory, and is

predicative of literacy development Administered via computer

Scores converted to standard scores, with a mean of 100, sd of 10

CN-Rep Results 1

Both groups of children scored below 100 on this task

Children with mild HI: mean= 87.75

Children with unilateral HI: mean=95.55

CN-Rep results by type of hearing impairment

811N =

type of hearing impairment

bilateralunilateral

95

% C

I CN

-Re

p S

tan

da

rdis

ed

sco

re110

100

90

80

70

CN-Rep results 2

Significant correlation of .953 with the recalling sentence CELF subtest (p=0.005) controlling for age

Scores can be compared with those from an OME group and hearing controls from BOS study

CN-Rep scores as a function of type of hearing impairment

110.7

105.2

95.6

87.8

70

75

80

85

90

95

100

105

110

115

None OME Unilateral Mild

type of hearing impairment

sta

nd

ard

sco

re

Results

Language

Non-word repetition

Cognition

Cognition Two tests from the British Abilities Scale

(BAS) Similarities (verbal reasoning)

Why do these things go together: “milk, lemonade, coffee” , “cod, shark, pilchard”

Need to produce the superordinate

Matrices (non verbal reasoning)Finish the pattern

Cognition results 1

Similarities (verbal reasoning)centile scores ranged from 17-84 mean of 45.71, sd 20

Matrices (non verbal reasoning)centile scores ranged from 29-99mean of 77.82, sd of 23.55

So - significantly impaired scores on verbal reasoning (p<.001 on independent samples t-test)

Cognition results 2

Only 3 children, all with mild HI, had higher verbal than non-verbal reasoning

Mean difference of 32 centiles between verbal and non-verbal scores

Significant difference in non-verbal score depending on type of HI Independent samples t test gives p=0.027

Cognition results

89 89N =

type of hearing impairment

bilateralunilateral

95

% C

I100

80

60

40

20

Similarities centile

matrices centile

Cognition results 4 Correlation of .625 between verbal

reasoning and CELF language scores (p=0.003)

Results can be compared across severity range with outcomes data from larger studies

Reasoning scores as a function of type of hearing impairment

0

10

20

30

40

50

60

70

t-sc

ore

Verbal

Reasoning scores as a function of type of hearing impairment

0

10

20

30

40

50

60

70

t-sc

ore

Verbal

Outcome measures conclusions

The caveat - These children were all identified through

CHAC. Therefore they have made it to the attention of the audiology services

There may be ascertainment bias which could effect the results and make generalisation more difficult

Outcome measures conclusions

Laterality of impairment for the unilateral group was not predictive of performance

Greater severity of impairment was correlated with better performance on language outcomes ...

… although numbers are very small

Outcome measures conclusions

Children with mild or unilateral hearing HI who are known to audiology services could be at risk for developing language problems

Children with a bilateral mild impairment are perhaps at greater risk than those with a unilateral impairment, regardless of severity

Overall conclusions

Children with mild impairments are showing language deficits that may possibly be ameliorated through earlier identification

There is a need for further research in the area of amplification provision for mild impairments

Overall conclusions

Children with unilateral impairments showed a variable performance which was not correlated with severity of impairment or side of impairment

There is the need for a larger study to investigate these findings further

Early identification through NHSP is still recommended

Thanks to

Adrian Davis and Sally Hind at MRC Institute of Hearing Research, Nottingham

Paul Shaw and the staff at CHAC, Nottingham

Helen Spencer & Jabulani Sithole for statistical assistance

Medical Research Council for PhD funding

Reasoning scores as a function of type of hearing impairment

0

10

20

30

40

50

60

70

t-sc

ore

Non Verbal

Reasoning scores as a function of type of hearing impairment

46

48

50

52

54

56

58

60

62

64

t-sc

ore

Non Verbal

Reasoning scores as a function of type of hearing impairment

0

10

20

30

40

50

60

70

NoneOM

EUnilateral

Mild

Moderate

Severe

Profound

t-sc

ore

Verbal

Non Verbal

Reasoning scores as a function of type of hearing impairment

0

10

20

30

40

50

60

70

NoneOM

EUnilateral

Mild

Moderate

Severe

Profound

t-sc

ore

Verbal

Non Verbal

Why does the prevalence increase with age? Is it…

new cases (i.e. acquired losses)?

progressive nature of mild cases?

late onset?

persistent OME?