Characterizing Variability in Reading Intervention Response among Children with Reading Disability in Independent Learning Disabilities Schools

Purpose: Across research studies and clinical observation, there is wide variability in reading intervention response among students with reading disability (RD). While many studies have investigated individual-level predictors of response in early readers, there have been fewer examinations in older, persistently poor readers. The current study focuses on a unique and understudied population of older students with RD who are enrolled in specialized schools that provide intensive and long-term reading intervention. We used nonlinear growth models to evaluate trajectories and predictors of reading intervention response in this population.Method: 108 student volunteers recruited in Grades 2-10 (age range = 7.1-16.1 years, mean = 10.5 years) were followed for up to six years (mean = 3.7 timepoints over 1.4 years). Exponential growth models were used to estimate individual trajectories of word-level reading (timed and untimed), with parameters for estimated capacity and growth rate predicted by phonological awareness (PA), rapid automatized naming (RAN), ADHD diagnosis, and DLD diagnosis.Results: Model estimates revealed that better PA and better RAN were significantly associated with higher word reading capacity estimates. PA was also significantly associated with growth rate. ADHD and DLD diagnoses were not significant predictors of reading trajectories.Conclusion: These findings are consistent with previous findings on predictors of reading intervention outcomes, but add to the literature by focusing on an understudied population of students with RD who attend specialized schools and through the use of nonlinear models to estimate growth.