Verlauf von Umschriebenen Entwicklungsstörungen: Eine 30-Monats-Follow-up-Studie

Abstract

Ziel dieser Untersuchung war die Überprüfung des kurzfristigen Entwicklungsverlaufs von Kindern mit Expressiven Sprachstörungen sowie solchen mit Lese-Rechtschreib- und Rechenstörungen an einer nicht-klinischen Stichprobe. Zudem sollten Kinder mit Umschriebenen Entwicklungsstörungen (UES) denen ohne diese Störungen mit Blick auf die Schullaufbahn gegenübergestellt werden. Die Untersuchungsdaten basieren auf den ersten beiden Messzeitpunkten der Potsdamer Längsschnittstudie. Zum ersten Messzeitpunkt besuchten 2287 Kinder im Alter von 5;10 bis 13;6 Jahren die erste bis fünfte Klasse. Für die Folgeuntersuchung nach ca. 2.5 Jahren konnten 69 % der Ursprungsstichprobe erneut gewonnen werden. Die Schüler im Alter von 8;2 bis 16;2 Jahren besuchten die zweite bis neunte Klassenstufe. Zur Erfassung der UES dienten die BUEGA ( Esser et al., 2008) sowie Verfahren zur Messung entsprechender Konstrukte ab der sechsten Klasse. Nur etwa 33 % der Kinder mit UES verbesserten sich in der entsprechenden Teilleistung. Höhere Besserungsraten ergaben sich bei separater Betrachtung für die Expressive Sprachstörung (46 %) sowie die isolierte Rechtschreibstörung (43 %). Demgegenüber erfüllten 63 % der Lese- und Rechtschreibgestörten auch bei der Folgemessung noch mindestens in einem Leistungsbereich (Lesen oder Rechtschreiben) die Störungskriterien. 90 % der Kinder, die zum ersten Messzeitpunkt mindestens die zweite Klasse besuchten und eine Rechenstörung aufwiesen, zeigten auch bei der Folgemessung mindestens unterdurchschnittliche Rechenleistungen, 40 % erfüllten weiter die Störungskriterien. Relativ zu Kindern ohne UES wiederholten signifikant mehr umschrieben Entwicklungsgestörte eine Klassenstufe, letztere besuchten zudem seltener das Gymnasium. Insgesamt unterstützen diese Ergebnisse die Annahme einer hohen Stabilität und negativen Prognose von UES und unterstreichen die Bedeutung einer frühzeitigen Diagnostik und Behandlung.

Long-term Course of Dyslexia, Dyscalculia and Expressive Language Disorder: A 30-month Follow-up Study

Backgrounds: The study focuses on the short-term course of specific developmental disorders in a community sample. It investigates the prognoses of children with specific language disorders, dyslexia as well as dyscalculia identified in primary school age.

Past research demonstrates that specific developmental disorders persist into adolescence and even into adulthood ( Beitchman et al., 1996a; Beitchman et al., 1996b; Esser, 1991; Shalev et al., 1998; Shalev et al., 2005). Children with specific developmental disorders are assumed to be at high risk for long-term adverse outcome, including poor academic performance and psychosocial problems ( Beitchman et al., 1996a; Beitchman et al., 1996b; Esser et al. 2002; Haffner et al., 1998; Johnson, Beitchman & Brownie, 2010). Esser and colleagues (2002) reported higher rates of unemployment at age 25 years in children with a diagnosis of dyslexia (at the age of 8) compared to children with average results in performance tests (e. g. reading, spelling). Most of these studies focus on the short-term or long-term courses of single specific developmental disorders. This study aims to investigate the prognoses of different developmental disorders. The analysis is based on a community sample in order to guarantee comparative analyses out of the same sample.

Aims: The study postulates that children with developmental disorders are often afflicted with their problems and display a worse academic achievement compared to children without any disorders. It applies to the first two measurement points of the Potsdam Longitudinal study. The initial sample consisted of 2287 five- to 13-year-old school children (mean age = 8;9; SD = 1;7 years). Within the second assessment, on average two and a half years later, 1581 eight- to sixteen-year-old school children (mean age = 11;4; SD = 1;7 years) were examined. While at measurement point 1 all children visited elementary schools from the first to the fifth grade, 21 % of the sample at measurement point 2 went to secondary schools. For the first assessment period the BUEGA ( Esser et al., 2008) was used to assess verbal and nonverbal intelligence as well as the performance in reading, spelling and mathematics. For the second measurement point children up to fifth grade were re-examined with the BUEGA. Children from sixth grade onwards were assessed by using alternative standardized tests appropriate for this age group.

Methods: In order to define specific developmental disorders, the following two criteria were employed: an achievement discrepancy as well as an IQ-achievement discrepancy of 1.5 standard deviations ( Esser et al., 2008). According to their achievement at the first wave of the study, children were diagnosed with the following developmental disorders: specific disorder of expressive language ( n = 39, 67 % girls), dyslexia (reading and/or spelling disability, n = 78, 37 % girls) or arithmetic disorder ( n = 14, 79 % girls). In order to compare the academic prognoses two further groups were set up: A control group of children without any specific developmental disorders and with average intellectual performance ( n = 1426, 51 % girls) as well as a group of children with intellectual deficits or mental retardation (intellectual performance was more than 2 SD below the age mean, ( n = 20, 55 % girls)).

Results: The results indicate that only about 33 % of all children with specific developmental disorders had improved their achievement to an average level in the specific partial performances at measurement point 2 (t ₂). These rates differ between the types of disorder. Out of all children who had been diagnosed with an expressive language disorder at t ₁, more than 45 % had overcome their language problems at t ₂, 23 % had a persisting diagnosis and 32 % did not fulfil the diagnostic criteria for an expressive language disorder but still showed language difficulties. Children with reading and spelling disorders were divided into three groups: isolated spelling disorder, isolated reading disorder and a combined reading and spelling disorder. More than 90 % of children with difficulties in reading and spelling retained problems in at least one partial performance and more than 60 % were still diagnosed as dyslexic. Contrary, out of all children with an isolated spelling disorder only 43 % retained their problems. Most of the children with an arithmetic disorder diagnosed in grade 2 or later had persisting arithmetic difficulties (90 %), and 40 % even fulfilled the diagnostic criteria for an arithmetic disorder. Contrary to this, an early diagnosis in the first grade caused unstable results, i. e. almost 50 % of the children with arithmetic disorders showed average arithmetic achievement at t ₂.

Additionally, children with specific developmental disorders were three times more often affected by repeating a school year than children of the control group. This is comparable to children with mental retardation. In order to evaluate the potential academic success the study had analysed the attendance to different types of secondary schools with different graduations. Children with a specific developmental disorder were less likely to attend academic high school (German Gymnasium) than children without these disorders.

Discussion: Overall, the results support the assumption of an adverse prognosis of specific developmental disorders and emphasize the importance of early diagnostics and treatment.