JCPSLP - March 2018

Developmental Language Disorder

Measuring language prog r ess in students with developmental language disorder while attending a specialist school A retrospective analysis Shaun Ziegenfusz, Amanda Coughlan, Jessica Paynter, Kate Simpson, and Marleen F. Westerveld

Students with developmental language disorder (DLD) are at risk of long-term academic and socio-emotional challenges. Evaluating these students’ progress on standardised measures following attendance at a language specialist school provides an opportunity to evaluate the impact of this model of service delivery on language progress. A retrospective chart analysis was conducted of all students enrolled in a language specialist school between 2005 and 2015. There was a total of 64 students who completed a standardised language assessment on two occasions, one of which occurred upon enrolment. Students were aged between 4 and 16 years at enrolment (M = 92.91 months). Students scored within the severe range consistent with expectations at Time 1 assessment. Significant improvements on standard scores were observed at Time 2 on receptive and expressive language scores. Time between assessments varied and was related to initial severity rather than progress over time. As a group, students demonstrated significant improvement in language skills during their enrolment at the school. Clinical implications and future directions are discussed. L anguage development for most children appears effortless. However, approximately 7 per cent of children will show persistent challenges known as developmental language disorder (DLD) (Bishop, Snowling, Thompson, Greenhalgh, & the CATALISE Consortium, 2017; Norbury et al., 2016). DLD is characterised by communication difficulties across form, content, and use, at word, sentence, and/or text levels (Bishop, Snowling, Thompson, Greenhalgh, & the CATALISE Consortium, 2016). Children with DLD form a heterogeneous population, with language profiles showing differing patterns of strengths, needs, and severity (Martínez, 2015). These language difficulties affect academic learning and persist into adolescence and adulthood (Catts, Hogan, & Adlof,

2005). Not surprisingly, DLD is known to increase the likelihood of unemployment and serious mental health problems (Clegg, Hollis, Mawhood, & Rutter, 2005; Johnson, Beitchman, & Brownlie, 2010). Further, there is a significant impact on the economy, as there is greater utilisation of health care by children with DLD relative to typically developing peers (Cronin, Reeve, McCabe, Viney, & Goodall, 2017; Le et al., 2016). Taken together, there is a clear need to better understand the developmental trajectories of children with DLD who receive specialised services. The present study aims to address this issue through retrospective chart analysis of language progress for a cohort of students with DLD who attended a language specialist school. Standardised norm-referenced language assessments, such as the Clinical Evaluation of Language Fundamentals (CELF-4; Semel, Wiig, & Secord, 2006), are frequently used to evaluate children’s language delays to inform DLD diagnosis (Betz, Eickhoff, & Sullivan, 2013; Bishop et al., 2016). Children with DLD display persistent low performance on such assessments in comparison to their typically developing peers in population studies (Tomblin, Zhang, Buckwalter, & O’Brien, 2003) and standard scores tend to be stable over time (Conti-Ramsden, St Clair, Pickles, & Durkin, 2012; Rice, 2013). Regression of language performance is rarely observed and is more commonly associated with other developmental disorders (Pickles et al., 2009). Likewise, longitudinal studies have failed to show accelerated growth in language performance after entering school. For example, Conti-Ramsden et al. (2012) evaluated the developmental trajectories of receptive language, expressive language, and non-verbal skills in school-age children with a history of DLD. Results showed that overall the children demonstrated consistent standardised scores on expressive and receptive language over a 10-year time period. Thus, while children with DLD continue to develop their language skills (as shown in raw score improvements), the gap between achieved skills compared to typically developing peers (standard scores) persists over time. More recently, McKean et al. (2017) identified variability in trajectories for language growth between 7 and 11 years. While the majority of children in the study (94%) demonstrated a stable trajectory during this time period, a small percentage of children’s language scores decreased (4%) while others increased (2%). Despite the mean trajectory of the stable group being flat, individual variability in the rate of progress showed language skills improved over time.

KEYWORDS CLINICAL EVALUATION OF LANGUAGE FUNDAMENTALS DEVELOPMENTAL

LANGUAGE DISORDER LANGUAGE PROGRESS SCHOOL AGE

THIS ARTICLE HAS BEEN PEER- REVIEWED

Shaun Ziegenfusz (top), Amanda Coughlan (centre) and Jessica Paynter,

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JCPSLP Volume 20, Number 1 2018

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