title: Early speech-language impairment and risk for written language disorder:  a population-based study.
abstract: 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.
authors.affiliation: Division of Neurology, Department of Speech Pathology, Mayo Clinic, Rochester, MN 55905, USA. stoeckel.ruth@mayo.edu
authors.forename: Ruth E
authors.initials: RE
authors.lastname: Stoeckel
authors.forename: Robert C
authors.initials: RC
authors.lastname: Colligan
authors.forename: William J
authors.initials: WJ
authors.lastname: Barbaresi
authors.forename: Amy L
authors.initials: AL
authors.lastname: Weaver
authors.forename: Jill M
authors.initials: JM
authors.lastname: Killian
authors.forename: Slavica K
authors.initials: SK
authors.lastname: Katusic
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004410:Dyslexia / Q000209:etiology; D004522:Educational Status; D005260:Female; D006801:Humans; D007806:Language Disorders / Q000209:etiology*; D007807:Language Tests; D008297:Male; D016016:Proportional Hazards Models; D012307:Risk Factors; D012737:Sex Factors; D013064:Speech Disorders / Q000150:complications*; D055815:Young Adult