Reading and communication skills after universal newborn screening for permanent childhood hearing impairment

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1 1 Shool of Psyhology, University of Southampton, Southampton, UK; 2 Shool of Mediine, Southampton General Hospital, University of Southampton, Southampton, UK; 3 UCL Institute of Child Health, London, UK; 4 Publi Health Sienes and Medial Statistis/RDSU, Shool of Mediine, University of Southampton, Southampton, UK; 5 National Perinatal Epidemiology Unit, University of Oxford, Oxford, UK Correspondene to: Colin Kennedy, Mailpoint 21, Child Health, Southampton General Hospital, Southampton SO16 6YD, UK; rk1@soton.a. uk Aepted 14 Otober 2008 Published Online First 17 vember 2008 Reading and ommuniation skills after universal newborn sreening for permanent hildhood hearing impairment D C MCann, 1 S Worsfold, 2 C M Law, 3 M Mullee, 4 S Petrou, 5 J Stevenson, 1 H M Yuen, 4 C R Kennedy 2 ABSTRACT Bakground: Birth in periods with universal newborn sreening (UNS) for permanent hildhood hearing impairment (PCHI) and early onfirmation of PCHI have been assoiated with superior subsequent language ability in hildren with PCHI. However their effets on reading and ommuniation skills have not been addressed in a population-based study. Methods: In a follow-up study of a large birth ohort in southern England, we measured reading by diret assessment and ommuniation skills by parent report in 120 hildren with bilateral moderate, severe or profound PCHI aged years, of whom 61 had been born in periods with UNS, and in a omparison group of 63 hildren with normal hearing. Results: Compared with birth during periods without UNS, birth during periods with UNS was assoiated with better reading sores (inter-group differene 0.39 SDs, 95% CI 0.02 to 0.76, p = 0.042) and ommuniation skills sores (differene 0.51 SDs, 95% CI 0.06 to 0.95, p = 0.026). Compared with later onfirmation, onfirmation of PCHI by age 9 months was also assoiated with better reading (differene 0.51 SDs, 95% CI 0.15 to 0.87, p = 0.006) and ommuniation skills (differene 0.56 SDs, 95% CI 0.12 to 1.00, p = 0.013). In the hildren with PCHI, reading, ommuniation and language ability were highly orrelated (r = , p,0.001). Conlusion: Birth during periods with UNS and early onfirmation of PCHI predit better reading and ommuniation abilities at primary shool age. These benefits represent funtional gains of suffiient magnitude to be important in hildren with PCHI. Previously we reported that universal newborn sreening (UNS) and early detetion of permanent hildhood hearing impairment (PCHI) were assoiated with higher sores for language at primary shool age. 1 A reent systemati review by the US Preventative Servies Task Fore (USPSTF) 2 assessed that study as providing good-quality evidene of benefit to language development and was aompanied by a USPSTF reommendation to sreen for hearing loss in all newborn infants. 3 In omparison with their hearing peers, hildren with PCHI also have poorer aademi outomes, partiularly reading attainment with an average reading age of 9 years when aged 17 years. 4 5 In this report, we extend our previously reported findings on language aquisition to examine the impat of early detetion of PCHI on applied pratial skills further along the ausal pathway, suh as reading and ommuniation skills. What is already known on this topi Bilateral permanent hildhood hearing impairment (PCHI).40 db hearing level impairs language and shool ahievement. Universal newborn sreening and onfirmation of PCHI by age 9 months improves language at primary shool age. What this study adds Original artile Universal newborn sreening and early onfirmation of permanent hildhood hearing impairment improve reading ability at primary shool age and adaptive behaviour with respet to ommuniation skills. The best estimate of the size of these benefits is around 0.5 SD. METHODS Communiation and reading skills were assessed at the same home visit and in the same hildren with bilateral PCHI >40 db hearing level, identified in a birth ohort in eight distrits of southern England, whose language abilities we reported previously. 1 In addition to the assessments previously reported, basi reading (BR) and reading omprehension (RC) sores were derived on the Weshler Objetive Reading Dimensions 6 (WORD). The ommuniation domain of the Vineland Adaptive Behaviour Sales (VABS) 7 was also ompleted, using information provided by the prinipal aregiver, usually the mother. Reading and ommuniation sores provided by a group of normally hearing hildren, born in the same hospitals and of similar age at assessment, were used to derive z sores (inluding z aggregate reading = zbr + zrc) for the hildren with PCHI. Consistent with our previous trial of UNS, 8 9 early onfirmation of PCHI was pre-speified as onfirmation by 9 ompleted months of age. Multiple linear regression (using Stata version 8 10 ) was used to examine the effets of birth in periods with UNS and of early onfirmation of PCHI on reading and ommuniation sores and to adjust for other explanatory variables, namely Arh Dis Child 2009;94: doi: /ad

2 Original artile severity of hearing impairment, non-verbal ability and maternal eduation. The South and West UK Multi-entre Researh Ethis Committee approved this study (MREC/99/6/77) and partiipating prinipal aregivers provided written informed onsent. RESULTS Of 168 identified hildren with bilateral PCHI in the ohort of births, 120 were enrolled and assessed at a mean (range) age of 7.9 ( ) years as were 63 hildren with normal hearing. 1 The harateristis of the families and hildren born in periods with and without UNS were similar exept that the mothers of babies born in periods without UNS tended, presumably by hane, to have ompleted eduation to a higher level (table 1). The median age of onfirmation of PCHI was 10 months (interquartile range 2 25) with a skewed distribution (mean 17.5 months). The hildren in the normally hearing omparison group were seleted to be English speaking. They had fewer health problems and were more likely to have parents in higher oupations than the hildren with PCHI but were in other respets similar to them (table 1). Table 1 Reading (WORD) and ommuniation skills (VABS) Sores for WORD and for VABS were available in 102 and 98 of 120 (85% and 82%), respetively, of the hildren with PCHI, inluding 16 and 11 hildren who used British Sign Language (BSL). The unadjusted sores for these measures, standardised for age, were signifiantly higher in the normal hearing omparison group than in the hildren with PCHI (table 2). Comparing the hearing-impaired group with the normally hearing group, we found larger defiits in language omprehension than in ommuniation and reading (table 2). Among hildren with PCHI, outome sores were onverted to z sores. There was a onsistent trend to higher unadjusted sores in those who were born during periods with UNS ompared with those born in periods without UNS or whose PCHI was onfirmed by 9 months of age ompared with those whose PCHI was onfirmed later. Effet of birth in periods with UNS After adjustment for severity of PCHI, mother s eduational level and the hild s non-verbal ability, group mean z sores for WORD aggregate reading and for the VABS ommuniation Charateristis of hearing-impaired and normally hearing hildren Hearing-impaired UNS rmally hearing UNS UNS n = 61 (%) n = 59 (%) n = 63 (%) Mean (range) of age at assessment 7.5 ( ) 8.3 ( ) 8.1 ( ) Female 26 (43) 27 (46) 26 (41) Degree of hearing loss Moderate 35 (57) 30 (51) na Severe 16 (26) 13 (22) na Profound 10 (16) 16 (27) na Other disabilities Cerebral palsy 2 (3) 3 (5) 0 Visual disability 5 (8) 8 (14) 0 Learning disability 3 (5) 5 (8) 0 Of hromosomal/syndromi origin 13 (21) 10 (17) 1 (2) Other 16 (26) 18 (31) ne 41 (67) 36 (61) 62 (98) Mode of ommuniation Oral sign language 50 (82) 47 (79) na Sign language only 6 (10) 10 (17) na n-verbal 5 (8) 2 (3) na n-verbal ability{ Above average 18 (30) 20 (34) 28 (44) Average 8 (13) 13 (22) 17 (27) Below average 29 (48) 20 (34) 18 (29) Mother s eduation* qualifiations or,5 O levels{ 27 (44) 16 (27) 25 (40) >5 O levels or some A levels{ 30 (49) 32 (54) 25 (40) University degree and above 4 (7) 10 (17) 13 (21) Oupation of head of household* Never worked/unemployed 10 (16) 8 (14) 2 (3) Lower oupations 10 (16) 8 (14) 14 (22) Intermediate oupations 20 (33) 16 (27) 12 (19) Higher oupations 23 (38) 26 (44) 35 (56) English first language at home Yes 54 (88) 45 (76) 60 (95) *Classified as per 2001 UK ensus; one missing value. {O levels (now replaed by general ertifiates of eduation) are usually taken at age 16 years; A levels (now replaed by A2s ) are taken 2 years later as qualifiations for entry to higher eduation. {Ravens Coloured Progressive Matries perentile sores for age; 12 missing values omprised of eight and four from hildren with early- and late-onfirmed permanent hildhood hearing impairments, respetively. na, not appliable. UNS, universal newborn sreening. 294 Arh Dis Child 2009;94: doi: /ad

3 Original artile Table 2 Unadjusted standardised sores for reading, ommuniation and language in hildren with and without permanent hildhood hearing impairment (PCHI) at primary shool age Numbers of hildren Mean sore (SD) Measure rmally hearing Hearing impaired rmally hearing (a) sale for those hildren born in periods with UNS were signifiantly higher than for hildren born in periods without UNS by 0.39 and 0.51, respetively (table 3). These adjusted sores were positively orrelated with previously reported 1 reeptive and expressive language z sores (r = , p,0.001). Effet of early detetion of PCHI Compared with sores in those whose PCHI was onfirmed later, adjusted group mean sores were also signifiantly higher in those whose PCHI was onfirmed by 9 months by 0.51 on WORD aggregate reading and 0.56 on the VABS ommuniation sale (Table 4). Compared to the size of effet of birth in periods with UNS and of early detetion of PCHI observed in all hildren with PCHI, the effet observed in hildren that used BSL was similar with respet to reading sores and larger with respet to ommuniation sores, but this was based on few observations. Mediating role of language Adding the aggregate language z sores to the regression models substantially redued the differenes between the group mean z sores, whether omparing hildren born in periods with and without UNS (to 0.16, 95% CI to 0.42, p = 0.24 for reading and 0.31, 95% CI to 0.70, p = 0.11 for ommuniation) or hildren whose PCHI was deteted early Hearing impaired (b) Mean differene (95% CI) (a2b) Reading WORD basi reading (15.5) 93.7 (17.7) 8.7 (3.4 to 14.1) WORD reading omprehension (15.2) 87.5 (16.5) 11.7 (6.6 to 16.8), Communiation VABS ommuniation (19.0) 93.9 (30.0) 14.5 (7.1 to 21.9) Language Reeptive (TROG) (15.3) 80.4 (15.0) 18.8 (14 to 23.6), Reeptive (BPVS) (12.6) 79.0 (19.7) 24.6 (19.7 to 29.5), Expressive (Bus Story information (9.7) 26.7 (12.1) 9.9 (6.4 to 13.5), sore) Expressive (Bus Story 2 average 5 longest sentenes) (2.3) 10.3 (3.4) 1.6 (0.7 to 2.5) Differene expressed as SDs of sore in (a) (a2b/sd of a) Mean sores are standardised for age at assessment but not otherwise adjusted. BPVS, British piture voabulary sale; TROG, test for assessment of grammar; and late (to 0.09, 95% CI to 0.36, p = 0.49 for reading and 0.19, 95% CI to 0.59, p = 0.33 for ommuniation), suggesting that the benefits to reading and ommuniation were partially mediated by greater language ability. Analysis in the Wessex subgroup In the Wessex subgroup, whose exposure to UNS (or not) was alloated in a ontrolled trial, the hane of unknown onfounding should have been redued. In this subgroup, the best estimate of the size of the effet of birth in periods with UNS on WORD aggregate reading sores and VABS ommuniation sale sores (table 5) was greater than that observed in the study population as a whole. This was also true with early onfirmation of the PCHI (f. tables 3 and 4 with tables 5 and 6). In the ase of aggregate reading sores, these inter-group differenes remained statistially signifiant (p = 0.04 and 0.004) in spite of redued numbers of observations (tables 5 and 6). DISCUSSION This population-based sample of hildren showed a signifiant assoiation between both birth in periods with UNS and also early detetion of PCHI on the one hand and higher mean sores at primary shool age for reading and ommuniation (by SDs) on the other. These outomes demonstrate gains in Table 3 Whole study sample: effet of birth in periods with universal newborn sreening (UNS) on reading and ommuniation z sores in hildren with permanent hildhood hearing impairment (PCHI) at primary shool age Born in periods with/without UNS for PCHI Group mean* z sore{ (SD) Z sores{ With UNS Without UNS With UNS (a) Without UNS (b) differene (95% CI) (a2b) differene (95% CI) WORD reading ability Basi reading (x) (1.19) (1.26) 0.31 (20.17 to 0.79) (20.00 to 0.80) Reading (1.12) (1.24) 0.22 (20.25 to 0.69) (20.02 to 0.77) omprehension (y) Aggregate reading (1.12) (1.25) 0.30 (20.17 to 0.77) (0.02 to 0.76) (x + y)/2 VABS ommuniation sale (1.13) (1.39) 0.43 (20.08 to 0.94) (0.06 to 0.95) {Negative sores indiate that sores were lower than those seen in the normally hearing omparison group. 1 Arh Dis Child 2009;94: doi: /ad

4 Original artile Table 4 Whole study sample: effet of early onfirmation of permanent hildhood hearing impairment (PCHI) on reading and ommuniation z sores in hildren with PCHI at primary shool age Age at onfirmation of PCHI Group mean* z sore{ (SD) (9 months.9 months (9 months.9 months differene (95% CI) differene (95% CI) WORD reading ability Basi reading (x) (1.18) (1.24) 0.45 (20.03 to 0.93) (0.17 to 0.93) Reading (1.18) (1.16) 0.38 (20.10 to 0.85) (0.09 to 0.86) omprehension (y) Aggregate (1.14) (1.21) 0.43 (20.04 to 0.89) (0.15 to 0.87) (x + y)/2 VABS ommuniation sale (1.16) (1.33) 0.53 (0.02 to 1.03) (0.12 to 1.00) {Negative sores indiate that sores were lower than those seen in the normally hearing omparison group. 1 skills that are important in daily living and of suffiient magnitude to be of funtional signifiane. This study may have underestimated the size of the benefit of UNS for reading and ommuniation skills for hildren with PCHI from birth beause this birth ohort was the first in the UK to whih UNS was applied so that intervals between sreening positive, onfirmation of PCHI and fitting of hearing aids were longer than is the urrent standard of are The data obtained in the Wessex subgroup were experimental sine their exposure to UNS was the intervention in a ontrolled trial, 8 9 suggesting a ause-and-effet relationship between UNS and higher subsequent reading and ommuniation sores. The only previous population-based study to examine the effet of age at first diagnosis on reading in hildren with PCHI of primary shool found no signifiant benefit. 13 The setting of that study differed from the present report in that the newborn sreening for PCHI had been undertaken in high-risk but not in standard-risk newborns. Other limitations of that study were the inlusion of hildren with only mild PCHI (21% of the sample), an asertainment rate of 89 of 132 eligible hildren (67%), and a relatively low rate of early onfirmation of PCHI with only 11 (12%) ases with PCHI deteted by age 6 months. We have previously reported that onfirmation of hearing impairment prior to age 9 months was assoiated with higher sores on language tests at age 8 years. 1 We hose language as the outome measure beause it an be preisely estimated by diret assessment and is on the ausal pathway from early intervention to better funtional outomes. For both theoretial and pratial reasons, however, those funtional outomes annot be inferred from the finding of higher language sores, as explained below. VABS ommuniation domain sores assess what the individual understands, says, reads and writes as refleted in behaviours as they our in an individual s environment rather than assessing responses to standardised auditory stimuli in a diret testing situation (ie, language testing). VABS ommuniation sores are higher in hildren with auditory impairments than in those with visual impairments whereas the reverse is true for language tests. 7 Communiation requires linguisti skills and the ability to deode a message that may also require auditory (as in spoken language), visual (as in gesture, lip movement and reading) or tatile (as in Braille) skills. Compared with that of normally hearing hildren, the ommuniation of hildren with hearing impairment depends to a greater extent on gesture, on awareness of soial ues and on other skills that ompensate for their redued auditory auity. These skills are assessed by ommuniation sores but not by standard language tests that are standardised on normally hearing hildren. Reading requires visual pereptual skills to aess a ognitive representation of linguisti information whereas in the ase of omprehension and expression of spoken language this aess is dependent on the ability to proess an auditory input and to generate a verbal utterane. Reading is thus less dependent than oral language on auditory auity whih is redued in hearing impairment. The existene of a relationship between the development of reading and language skills is well established in normally hearing hildren 14 but poorly understood in hearingimpaired hildren. In the present study, the greater defiits in language than in reading relative to those of the normally hearing omparison group suggest that the language sores underestimated ommuniating ability in the hearing-impaired hildren. This limitation on the use of language sores as a Table 5 Wessex-ontrolled trial subgroup: effet of birth in a period with universal newborn sreening (UNS) on reading and ommuniation z sores in hildren with permanent hildhood hearing impairment (PCHI) at primary shool age Born in periods with/without UNS Group mean* z sore{ (SD) Z sores{ WORD aggregate reading VABS ommuniation sale With UNS Without UNS With UNS (a) Without UNS (b) differene (95% CI) (a2b) differene (95% CI) (1.30) (1.14) 0.51 (20.26 to 1.29) (0.026 to 1.13) (21.30) (1.16) 0.32 (20.47 to 1.11) (20.21 to 1.24) 0.16 {Negative sores indiate that sores were lower than those seen in the normally hearing omparison group Arh Dis Child 2009;94: doi: /ad

5 Original artile Table 6 Wessex-ontrolled trial subgroup: effet of early onfirmation of permanent hildhood hearing impairment (PCHI) on reading and ommuniation z sores in hildren with PCHI at primary shool age WORD aggregate reading VABS ommuniation sale Age at onfirmation of PCHI Group mean* z sore (SD) differene (95% CI) (9 months.9 months (9 months.9 months measure of the benefit of UNS is irumvented by showing the benefits to reading and ommuniation reported here. The proesses and mehanisms that underlie the development of reading ability in these hildren are not lear and may differ from those known to play a strong preditive role in the early development of reading skills in normally hearing hildren. These inlude language skills suh as voabulary and phonologial awareness (the ability to segment and blend the sounds of a language eg, identifying the rhyme that is ommon to hat, bat and at ) Reading for 7 8-year-old hildren with a severe to profound PCHI, for example, was reported to be predited by expressive voabulary and speeh reading (ie, the hild s ability to attend to the shape of the lips and mouth in understanding oral speeh) but not by phonologial awareness. 19 It is, however, possible that UNS followed by early onfirmation of PCHI may allow hildren to follow a path to literay more similar to that of hearing hildren. Our observation of higher sores for reading and ommuniation in the setting of UNS provides evidene that provision of UNS and onfirmation of PCHI by 9 months an be expeted to lead not only to higher sores on formal tests of language ability, but also to pratial benefits to the reading and ommuniation skills of these hildren, inluding the subgroup that uses BSL. Further assessment of the partiipating hildren after longer follow-up is planned to establish whether these hildren show improvement at high shool age in language, reading, soial ommuniation, and shool attainment. Aknowledgements: We are grateful for the funding support of The Wellome Trust (Ref ). We gratefully aknowledge the help and assistane reeived from hildren, families, shool staff, Speialist Teahers of the Hearing Impaired, partiularly Jan Nanor in London, Speeh and Language Pathologists, and Audiology professionals in the loal area teams. We partiularly thank the following senior Audiology staff: Dr Margaret Baldwin, Dr Joy Bhattaharya, Dr Alyson Bumby, Iris Curtis, Dr Carol Hunter, Dr David Reed, Sott Rihards, Sue Robinson, Dr Peter Savundra, Mr Huw Thomas, Dr Peter Watkin and Dr Tim Williamson. We thank Ros Herman for the assessments of British Sign Language. We also thank the team of researhers (Helen Davis, Shirley Golden, Eleanor Lutman, Kristen Paul and Helen Ryder) for their exellent work. We thank Julie Brinton and Hazel Blythe at the University of Southampton for their advie to the authors. Funding: This study was funded by a grant from the Wellome Trust (referene ). The authors work was independent of the funders and the funders had no involvement. The sponsors of the study had no role in the study design, data olletion, data analysis, data interpretation or writing of the report. Competing interests: ne. Ethis approval: The South and West UK Multi-entre Researh Ethis Committee approved this study. differene (95% CI) (1.41) (1.13) 0.43 (21.24 to 0.38) (21.29 to 20.25) (1.46) (1.05) (21.35 to 0.26) (21.43 to 0.005) Patient onsent: Parental onsent obtained. The design and appliation for funding was developed from an idea by CRK with the help of CML, MM, SP, JS and SW. 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