Hearing impairment: a population study of age at diagnosis, severity, and language outcomes at 7-8 years.
BACKGROUND
Better language outcomes are reported for preschool children with hearing impairment (HI) diagnosed very early, irrespective of severity. However, population studies of older children are required to substantiate longer term benefits of early detection.


OBJECTIVE
To study impact of age of diagnosis and severity of HI in a population cohort of 7-8 year old children.


METHODS
Eighty eight 7-8 year old children born in Victoria, who were (a) fitted with hearing aids for congenital HI by 4.5 years and (b) did not have intellectual or major physical disability were studied. Main outcome measures were Clinical Evaluation of Language Fundamentals (CELF) and Peabody Picture Vocabulary Test (PPVT). Predictors were pure tone average (0.5, 1, 2 kHz) in better ear at diagnosis and age at diagnosis. Marginal (adjusted) means were estimated with general linear models.


RESULTS
Response rate was 67% (n = 89; 53 boys). Mean age at diagnosis was 21.6 months (SD 14.4); 21% had mild, 34% moderate, 21% severe, and 24% profound HI; mean non-verbal IQ was 104.6 (SD 16.7). Mean total CELF score was 76.7 (SD 21.4) and mean PPVT score 78.1 (SD 18.1). Age of diagnosis, adjusted for severity and IQ, did not contribute to language scores. In contrast, adjusted mean CELF and PPVT language scores fell sequentially with increasing severity of HI.


CONCLUSIONS
More severe HI, but not later diagnosis, was strongly related to poorer language outcomes at 7-8 years. Further systematic study is needed to understand why children with hearing impairment have good or poor outcomes.
Wake
M
M
Centre for Community Child Health, Murdoch Childrens Research Institute, Melbourne, Australia. melissa.wake@rch.org.au
Poulakis
Z
Z
Hughes
E K
EK
Carey-Sargeant
C
C
Rickards
F W
FW
D017668:Age of Onset; D000704:Analysis of Variance; D002648:Child; D015331:Cohort Studies; D005260:Female; D006304:Health Status; D006311:Hearing Disorders / Q000151:congenital / Q000175:diagnosis* / Q000523:psychology; D006801:Humans; D007806:Language Disorders / Q000209:etiology* / Q000517:prevention & control; D008297:Male; D011379:Prognosis; D011932:Reading; D012044:Regression Analysis; D011795:Surveys and Questionnaires; D014739:Victoria
Int J Audiol. 2003 Oct;42(7):385-90
14582634
Int J Pediatr Otorhinolaryngol. 1998 Aug 1O;44(3):309-10
9780076
Int J Lang Commun Disord. 1999 Jul-Sep;34(3):243-64
10884901
JAMA. 2001 Oct 24-31;286(16):2000-10
11667937
Audiol Neurootol. 2002 Mar-Apr;7(2):114-21
12006739
Ann Otol Rhinol Laryngol Suppl. 2002 May;189:74-8
12018355
Pediatrics. 1998 Nov;102(5):1161-71
9794949
Br J Audiol. 1986 May;20(2):165-7
3719164
Br J Audiol. 1992 Apr;26(2):97-107
1628121
Arch Dis Child. 1995 Jan;72(1):11-5
7717729
Br J Audiol. 1995 Dec;29(6):315-34
8861408