Interpreting comprehension outcomes after multiple-component reading intervention for children and adolescents with reading disabilities

Many children and adolescents with reading comprehension difficulties demonstrate impairment in lexical and sublexical foundational skills, and require intervention for multiple levels of the reading system. This paper provides a merged analysis of results from four controlled intervention studies conducted by our research group: Children and adolescents with reading disabilities (RD) received multiple-component remediation at different ages (early elementary, middle school, high school). All participants demonstrated multi-faceted reading impairment, and all received intervention targeting decoding, word reading, text reading, and comprehension skills. Studies with younger children (Grades 1-3) demonstrated more robust comprehension effects on multiple comprehension measures, while studies with older readers demonstrated more equivocal comprehension effects despite gain on more foundational skills. A parallel moderated-mediation model, using data merged across studies, revealed that intervention-related decoding and word reading change mediated the relationship between intervention and reading comprehension gains. This mediation effect was strongly moderated by age, with younger children demonstrating the greatest mediation. The younger the child, the greater the effects of inter-vention and the more comprehension gains depended on decoding gains.