Authors: Elise H. de Bree, Madelon van den Boer, Boukje M. Toering, Peter F. de Jong.
Publication: Dyslexia (Wiley). First published: 18 May 2022 2022 | DOI: 10.1002/dys.1712
When dyslexia is diagnosed late, the question is whether this is due to late-emerging (LE) or late-identified (LI) problems. In a random selection of dyslexia-diagnosis case files we distinguished early-diagnosed (Grade 1–3, n = 116) and late-diagnosed (Grade 4–6) dyslexia. The late-diagnosed files were divided into LE (n = 54) and LI dyslexia (n = 45). The LE group consisted of children whose national-curriculum literacy outcomes did not warrant referral for dyslexia diagnosis in Grades 1–2; the LI group of children whose literacy outcomes did, but who were referred for diagnostic assessment after Grade 3. At the time of diagnosis, the percentage of poor performers on word-level literacy measures generally did not differ between the groups. Only the LE group contained fewer poor performers than the early-diagnosed and LI group on some word-reading measures. All groups showed similar distributions of phonological difficulties. There were no indications of compensation through vocabulary, memory or IQ in either late-diagnosed group. Our diagnosis-based study confirms and extends previous research-based studies on LE dyslexia. Moreover, it shows that LI dyslexia exists, which can be regarded as the existence of instructional casualties. The findings speak to issues of identification, diagnosis and compensation and call for further efforts to improve the early identification of dyslexia.
- Ideally, severe and persistent word-level reading difficulties (dyslexia) are detected as early as possible.
- Our findings confirm findings that late-emerging dyslexia exists, meaning that the severe and persistent poor performance surface later.
- We also found that late-identified dyslexia exists, meaning that children were referred later than their reading outcomes warranted.
- The late-emerging and late-identified groups do not show evidence of compensation of literacy abilities.
- Efforts should be made to avoid such instructional casualties (late-identified dyslexia) and to support the school literacy curriculum.
de Bree, E. H., van den Boer, M., Toering, B. M., & de Jong, P. F. (2022). A stitch in time…: Comparing late-identified, late-emerging and early-identified dyslexia. Dyslexia, 1– 17. https://doi.org/10.1002/dys.1712
At the end of Grade 1, the LI group resembled the early-diagnosed group in word-level literacy, the selection criterion, but also in text reading and reading comprehension. As reading comprehension can be argued to largely reflect word-reading ability at this early phase of literacy instruction, the reading comprehension findings match those of the poor word reading skills of the groups. At the time of the diagnosis, word reading and spelling deficits were also similar in both groups. In contrast, the LE group contained fewer children with word reading accuracy and speed deficits at the time of diagnosis.