Reading disability defined as a discrepancy between listening and reading comprehension: a longitudinal study of stability, gender differences, and prevalence.

The purpose of this study was to determine whether defining reading disability by a discrepancy between group-administered tests of listening and reading comprehension would produce result similar in terms of stability, gender ratio, and prevalence to IQ-achievement test discrepancy definitions. The total population of a small school district (N = 1,008) was followed from prekindergarten through Grade 7-8 for 13 years. As is often seen in epidemiological studies using IQ and individually administered reading tests to define reading disability, stability in the classification of reading disability was low. Among the participants with a consistent reading disability, the male-to-female ratio was 3.2:1, compared with 1.3:1 for the 5.1% of the sample who were nondiscrepant poor readers in both lower and upper grades. A mean 2.7% of the population was classified as reading disabled over the eight-grade span, and only 1.7% demonstrated a consistent reading disability in both the lower and the upper grades. An increase in the ratio of nondiscrepant to discrepant poor readers after Grade 5 was due mainly to late-emerging poor readers. It was concluded that defining reading comprehension disability in terms of a discrepancy between listening and reading comprehension provides a fairly accurate estimate of the stability, gender ratio, and prevalence of the disorder.