Effectiveness of treatment approaches for children and adolescents with reading disabilities: a meta-analysis of randomized controlled trials

Abstract

Children and adolescents with reading disabilities experience a significant impairment in the acquisition of reading and spelling skills. Given the emotional and academic consequences for children with persistent reading disorders, evidence-based interventions are critically needed. The present meta-analysis extracts the results of all available randomized controlled trials. The aims were to determine the effectiveness of different treatment approaches and the impact of various factors on the efficacy of interventions. The literature search for published randomized-controlled trials comprised an electronic search in the databases ERIC, PsycINFO, PubMed, and Cochrane, and an examination of bibliographical references. To check for unpublished trials, we searched the websites clinicaltrials.com and ProQuest, and contacted experts in the field. Twenty-two randomized controlled trials with a total of 49 comparisons of experimental and control groups could be included. The comparisons evaluated five reading fluency trainings, three phonemic awareness instructions, three reading comprehension trainings, 29 phonics instructions, three auditory trainings, two medical treatments, and four interventions with coloured overlays or lenses. One trial evaluated the effectiveness of sunflower therapy and another investigated the effectiveness of motor exercises. The results revealed that phonics instruction is not only the most frequently investigated treatment approach, but also the only approach whose efficacy on reading and spelling performance in children and adolescents with reading disabilities is statistically confirmed. The mean effect sizes of the remaining treatment approaches did not reach statistical significance. The present meta-analysis demonstrates that severe reading and spelling difficulties can be ameliorated with appropriate treatment. In order to be better able to provide evidence-based interventions to children and adolescent with reading disabilities, research should intensify the application of blinded randomized controlled trials.

Figure 1. Flow chart of study selection process.

Figure 2. Treatment efficacy on reading performance.

Funnel plot displays treatment efficacy on reading performance for each comparison of an experimental group with a control group. ADD = Adding phonemes; CG = Control group; DI = Direct instruction; DS = Decoding skills; EXC = Exceptional; LPA = Sound-symbol correspondence and phonemic awareness; MA = Morphological awareness; OWLS = Oral and written language skills; PADS = Phonemic awareness and decoding skills; PAT = Phonological awareness training; PG = Placebo-control group; PHAB = Phonological analysis and blending; REG = Regular; SMS = Specific motor sequence; SP = Speech perception; SRT = Strategy reciprocal teaching; TCS = Text content and structure; TOD = Temporal order detection; WIST = Word identification strategy training; WAT = Word analogy training; WW = Write a word.

Figure 3. Treatment efficacy on spelling performance.

Funnel plot displays treatment efficacy on spelling performance for each comparison of an experimental group with a control group. ADD = Adding phonemes; CG = Control group; DI = Direct instruction; DS = Decoding skills; EXC = Exceptional; MA = Morphological awareness; OWLS = Oral and written language skills; PAT = Phonological awareness training; PG = Placebo-control group; PHAB = Phonological analysis and blending; REG = Regular; SMS = Specific motor sequence; WIST = Word identification strategy training; WAT = Word analogy training; WW = Write a word.

Figure 4. Funnel plot of standard error by Hedges g for observed comparisons.

Funnel plot displays observed comparisons evaluating the efficacy of phonics instructions on reading performance.

Figure 5. Funnel plot of standard error by Hedges g for observed and imputed comparisons.

Funnel plot displays observed and imputed comparisons evaluating the efficacy of phonics instructions on reading performance.