Reading and math achievement in children with dyslexia and/or developmental language disorder

Reading and math achievement in children with dyslexia and/or developmental language disorder

First Author: Suzanne Adlof -- University of South Carolina
Additional authors/chairs: 
Alison Eisel Hendricks
Abstract / Summary: 

Purpose: Children with language-based learning disabilities, including dyslexia and developmental language disorder (DLD), account for over 50% of children receiving special education services in the USA. Yet, much evidence suggests that DLD and dyslexia are under-diagnosed. This study examined differences in reading and math achievement from 2nd to 4th grade among subgroups of children meeting research criteria for dyslexia and/or DLD vs. typical development (TD).

Method: Participants (total N = 335; 42 Dys-only, 59 DLD-only, 89 Dys+DLD, 145 TD) were identified via universal screening and individual diagnostic testing when they were in 2nd grade. Participants completed Reading and Math assessments from the Measures of Academic Progress (MAP) twice yearly from 2nd to 4th grade as part of district-wide progress monitoring. The MAP provides Rasch-model scores for comparing students’ performance within and across grade levels.

Results: Children with dyslexia and/or DLD scored significantly lower than TD children in reading and math across all time points. Children with DLD-only outperformed children with Dys-only on the MAP Reading in 2nd grade; however, the Dys-only and DLD-only groups did not differ from each other on MAP Math at any grade or MAP Reading after 2nd grade. Children with combined Dys+DLD showed the poorest performance in both subjects across grades. Few children classified as dyslexia and/or DLD were receiving any special education services (18% Dys-only; 2% DLD-only; 35% Dys+DLD). Future analyses will examine proportions of children in each subgroup meeting grade-level benchmarks in each subject.

Conclusions: Results underscore the need for improved identification and treatment of language-based learning disabilities.