Objective: To compare risk of written language disorder (WLD) in children with and without speech-language impairment (S/LI) from a population-based cohort.
Methods: Subjects included all children born between 1976 and 1982 in Rochester, Minnesota, who remained in the community after age 5 years (n = 5718). Records from public and private schools, medical agencies, and tutoring services were abstracted. S/LI was determined based on eligibility criteria for an individualized education plan. Incident cases of WLD were identified by research criteria using regression-based discrepancy, non–regression-based discrepancy, and low-achievement formulas applied to cognitive and academic achievement tests. Incidence of WLD (with or without reading disorder [RD]) was compared between children with and without S/LI. Associations were summarized using hazard ratios.
Results: Cumulative incidence of WLD by age 19 years was significantly higher in children with S/LI than in children without S/LI. The magnitude of association between S/LI and WLD with RD was significantly higher for girls than for boys. This was not true for the association between S/LI and WLD without RD.
Conclusions: Risk for WLD is significantly increased among children with S/LI compared with children without S/LI based on this population-based cohort. Early identification and intervention for children at risk for WLD could potentially influence academic outcomes.
*Division of Neurology, Department of Speech Pathology and
†Department of Psychiatry and Psychology, Mayo Clinic, Rochester, MN
‡Department of Developmental Medicine, Children’s Hospital Boston, Boston, MA
§Division of Biomedical Statistics and Informatics
‖Division of Epidemiology, Department of Health Science Research, Mayo Clinic, Rochester, MN.
Address for reprints: Ruth E. Stoeckel, PhD, Division of Neurology, Department of Speech Pathology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905; e-mail: firstname.lastname@example.org.
Disclosure: The authors declare no conflict of interest.
Received August , 2012
Accepted October , 2012