Children with Mild and Unilateral Hearing Impairment

1. 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

2. Overview • Current management for children with mild and unilateral hearing impairment (HI) • Outcome measures: • Speech and language • Cognition

3. 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

4. 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

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

6. 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

7. How was it done? • Single page questionnaire survey • Sent out to 131 professionals throughout the UK • 1 reminder • 56 responses (43%)

8. Results • Information on the mild and unilateral cases seen • Management offered to those cases

9. Results • Information on the mild and unilateral cases seen • Management offered to those cases

10. 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

11. 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

12. Numbers of children seen

13. 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

14. Age of Referral

15. 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

16. 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

17. Results • Information on the mild and unilateral cases seen • Management offered to those cases

18. Management

19. 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)

20. 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)

21. 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

22. Outcome Measures –Language and Cognition

23. 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

24. 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.

25. 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)

26. 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.

27. Results • Language • Non-word repetition • Cognition

28. Results • Language • Non-word repetition • Cognition

29. 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

30. 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

31. Unilateral HI Mild HI Total Language Scores for individual subjects

32. 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.

33. 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

34. Results • Language • Non-word repetition • Cognition

35. 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

36. 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

37. CN-Rep results by type of hearing impairment

38. 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

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

40. Results • Language • Non-word repetition • Cognition

41. 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

42. 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)

43. 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

44. Cognition results

45. 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

46. Reasoning scores as a function of type of hearing impairment

47. Reasoning scores as a function of type of hearing impairment

48. 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

49. 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

50. 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