Prevalence of Dyslexia and Its Relationship with Decoding and Comprehension in Persian-speaking Elementary Students

Dyslexia, a neurodevelopmental disorder characterized by difficulties in word recognition and decoding, remains underexplored in non-Western orthographies such as Persian. To estimate the prevalence of dyslexia and examine the relationship between decoding and reading comprehension among Persian-speaking elementary students.

A cross-sectional study was conducted among 1,400 students (Grades 2-5) using a multistage stratified-cluster sampling design. Dyslexia was identified using the nonword reading subtest of a standardized reading and dyslexia test, with intellectual functioning assessed via the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV). Survey-weighted logistic and linear regression models were used to analyze associations and interactions, with a Bonferroni correction (p < .0083) applied for multiple comparisons. Confidence intervals (CI) and odds ratios (OR) are reported.

The weighted prevalence of dyslexia was 10.40% (95% CI: 9.00-12.05), with higher rates in boys (14.50%, 95% CI: 12.42-16.92, OR: 2.66, 95% CI: 1.90-3.71, p < .001) than girls (6.01%, 95% CI: 4.61-7.80) and in private versus public schools (6.40% vs. 12.08%, OR: 0.50, 95% CI: 0.33-0.75, p = .002). Word reading and comprehension were significant protective factors (p < .001), while phonological awareness was non-significant in adjusted models. Decoding strongly predicted comprehension in typical readers, but this association was significantly weaker in dyslexic students (p = .006).

Dyslexia affects approximately one in 10 Persian-speaking students, with variations influenced by gender, school type, and reading skills. Comprehensive screening and interventions targeting decoding and comprehension are critical, particularly in public schools.