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EDHI Feb 2004. Children with Mild and Unilateral Hearing Impairment. Current management and outcome measures. Kirsti Reeve Ph.D. Developmental Disabilities Institute Wayne State University, Detroit MI. Overview.
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EDHI Feb 2004 Children with Mild and Unilateral Hearing Impairment Current management and outcome measures Kirsti Reeve Ph.D. Developmental Disabilities Institute Wayne State University, Detroit MI
Overview • Current management for children with mild and unilateral hearing impairment (HI) • Outcome measures: • Speech and language • Cognition
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 studies • Questionnaire survey to audiologists investigating management options • Outcomes 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 uncertainty • Numbers of children being identified • Age of identification • Management options for these groups • Level 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 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
100 90 X 80 X 70 X 60 X 50 X Moderate 40 X All Trent 30 , Mild Unilateral 20 X , 10 , 0 , ) ' 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 Age of referral, data from Trent Region(Mild n=50, Unilateral = 30) percentiles Age in months
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 • 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 whetherto provide aids and at what level for children with a bilateral mild impairment
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 lateralization • Standardised language assessment (CELF-3 UK) • Children’s test of Non word Repetition • BAS 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
Means of all language scores Standardised Test: mean:100, sd:15 Receptive Language Mean: 89.65, sd 13.18 Expressive Language Mean: 85.76, sd 13.51 Total Language Mean: 86.29, sd 14.01
Unilateral HI Mild HI Total Language Scores for individual subjects
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 impairment • 24 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 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
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 29-99 • mean 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 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
Reasoning scores as a function of type of hearing impairment
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