Investigating the Prevalence of Dyslexia and its Characteristics in Elementary School Students

Learning disabilities are common childhood disorders. Educational problems are the most significant indicator of learning disorders that can be observed in different areas. Reading is among the most fundamental aspects of learning in elementary school; thus, the identification of students with dyslexia is of particular importance. Reading ability requires basic skills, such as the development of language skills, motor skills, visual skills, listening skills, the ability to visual and auditory separation, ultimately attention and focus. The most frequent causes of dyslexia are impaired auditory perception, poor visual and auditory processing, inability to understand the words, inability to understand essential aspects of words, sentences, and paragraphs, and inability to understand speech units presented by letters. Therefore, the present study aimed to determine the prevalence of dyslexia and its characteristics in second–grade primary school students.

This was a cross–sectional and descriptive–analytical study. The statistical population of this study was all boys and girls of the second grade of elementary schools in 4 educational districts of Ahwaz City, Iran, who studied in public schools during the academic year of 2017–2018. To conduct this research, 387 male and female students were selected through the multistage cluster sampling method and based on Krejcie and Morgan’s table (1970). The inclusion criteria of the current study included studying in the second grade of elementary school, the Intelligent Quotient (IQ) of above 85 as per Ravenchr('39')s progressive matrices (Raven, 1956), poor reading performance according to the studentchr('39')s teachers, and achieving scores of two deviations of the criterion below the average in reading and dyslexia tests (Nama) (Kormi Nouri & Moradi, 2006). Furthermore, having any behavioral disorders, hyperactivity, and mental disability, vision and hearing impairments, epilepsy, and using psychiatric drugs were considered as the exclusion criteria; these criteria were examined by referring to students’ educational and health records and interviewing teachers, principals, and studentchr('39')s parents as well as clinical and behavioral observations. During the tests, students suspected of having these problems were also excluded. A small number of the surveyed students, in addition to Persian, spoke Arabic at home, i.e., examined according to the studentschr('39') Persian vocabulary. Besides, if the student was very unfamiliar with Persian, she or he was excluded from the research. Then, the Raven Colored Progressive Matrices Test (Raven, 1956) and a reading and Dyslexia Diagnostic Test (NAMA) (Karami Noori & Moradi, 2006) were performed for evaluating reading and dyslexia. The obtained data were analyzed using descriptive indices, including mean and standard deviation, Chi–squared test, and the significance of two independent ratios test in SPSS. The significance level of all tests was considered to be 0.05.

The dyslexia ratio of the explored male students was obtained as 0.104; the dyslexia ratio of female students was calculated as 0.06; thus, there was no significant difference between the comparable ratios (p>0.05). According to the results of the Chi–squared test and comparing the prevalence of dyslexia in the 4 educational districts of Ahwaz, the prevalence of dyslexia in some educational regions was higher than the other ones (p<0.001).

Based on the present study results, the prevalence rate of dyslexia was equal among students in the public schools of Ahwaz. Furthermore, the prevalence of dyslexia was different in the 4 educational districts of Ahwaz.