Courtenay Norbury|Debbie Gooch|Charlotte Wray|Gillian Baird|Tony Charman|Emily Simonoff|George Vamvakas|Andrew Pickles
The impact of nonverbal ability on prevalence and clinical presentation of language disorder: evidence from a population study
University College London|Royal Holloway University of London|University College London|Royal Holloway University of London|Royal Holloway University of London|St Thomas' Hospital|King's College London|King's College London|King's College London|King's College London
background diagnosis specific language impairment traditionally required nonverbal iq within normal limits often resulting restricted access clinical services children lower nviq changes dsm 5 criteria language disorder removed nviq requirement study sought delineate impact varying nviq criteria prevalence clinical presentation functional impact language disorder first uk population study language impairment school entry methods populationbased survey design sample weighting procedures used estimate population prevalence surveyed statemaintained reception classrooms n 161 61 eligible schools surrey england total population 12398 children ages 45 years 7267 59 screened stratified subsample n 529 received comprehensive assessment language nviq social emotional behavioural problems academic attainment results total population prevalence estimate language disorder 992 95 ci 738 1320 prevalence language disorder unknown origin estimated 758 95 ci 533 1066 prevalence language impairment associated intellectual disability andor existing medical diagnosis 234 95 ci 140 391 children language disorder displayed elevated symptoms social emotional behavioural problems relative peers f 1 466 788 p 05 88 make expected academic progress differences average lowaverage nviq scores severity language deficit social emotional behavioural problems educational attainment contrast children language impairments associated known medical diagnosis andor intellectual disability displayed severe deficits multiple measures conclusions school entry approximately two children every class 30 pupils experience language disorder severe enough hinder academic progress access specialist clinical services depend nviq