Relationship between clinical symptoms and Hiragana reading ability in children with difficulties in reading and writing: Usefulness of a clinical-symptoms-checklist

We investigated the clinical symptoms of children with developmental dyslexia (DD) and evaluated the relationship between these symptoms and their Hiragana reading abilities. In order to detect the clinical symptoms of DD, we newly developed a clinical-symptoms-checklist (CL), which consisted of a total of 30 yes/no questions regarding symptoms linked to reading (15 questions) and writing (15 questions). Subjects were 98 Japanese school grade (1 to 9) children, aged 6 to 15 years old, with normal intelligence confirmed by the Wechsler Intelligence Test for Children (WISC-III) and they were divided into 2 groups according to their diagnosis. Twenty four children diagnosed as developmental dyslexia consisted the DD group, and the remaining 74 children were grouped in the non-DD group. CL showed significant construct validity (p<0.05) and inner consistency (reading: α =0.82, writing: α =0.72) after deleting two questions from the originals. The number of questions checked in the CL reading subcategory significantly correlated with the Hiragana reading ability of articulation time in all Hiragana reading tasks (p<0.001). More severe clinical symptoms and lower reading ability were observed in the DD group compared to the non-DD group. Receiver Operating Characteristics (ROC) analysis indicated that these two groups could be discriminated by the CL and the results of the reading task, and both sensitivity and specificity rate were approximately 80%. It was suggested that 7 or more positive checks in the CL and 2 or more abnormal scores in the reading tasks might discriminate DD from other conditions which cause difficulties in reading and writing in Japanese children.