title: Risk and Protective Factors for Late Talking: An Epidemiologic Investigation.
abstract: To identify risk and protective factors for late talking in toddlers between 24 and 30 months of age in a large community-based cohort.
  
  
  
  A prospective, longitudinal pregnancy cohort of 1023 mother-infant pairs in metropolitan Calgary, Canada, were followed across 5 time points: before 25 weeks gestation, between 34-36 weeks gestation, and at 4, 12, and 24 months postpartum. Toddlers who scored ≤10th percentile on The MacArthur-Bates Communicative Development Inventories: Words and Sentences between 24 and 30 months of age were identified as late talkers. Thirty-four candidate characteristics theoretically and/or empirically linked to language development and/or language impairment were collected using survey methodology.
  
  
  
  The prevalence of late talking was 12.6%. Risk factors for late talking in the multivariable model included: male sex (P = .017) and a family history of late talking and/or diagnosed speech or language delay (P = .002). Toddlers were significantly less likely to be late talkers if they engaged in informal play opportunities (P = .013), were read to or shown picture books daily (P < .001), or cared for primarily in child care centers (P = .001).
  
  
  
  Both biological and environmental factors were associated with the development of late talking. Biological factors placed toddlers at risk for late talking, and facets of the environment played a protective role. Enveloping infants and toddlers in language-rich milieus that promote opportunities for playing, reading, and sharing books daily may decrease risk for delayed early vocabulary.
authors.affiliation: University of Calgary, Calgary, Alberta, Canada. Electronic address: beverly.collisson@ucalgary.ca.
authors.forename: Beverly Anne
authors.initials: BA
authors.lastname: Collisson
authors.affiliation: University of Calgary, Calgary, Alberta, Canada.
authors.forename: Susan A
authors.initials: SA
authors.lastname: Graham
authors.affiliation: Syracuse University, Syracuse, NY.
authors.forename: Jonathan L
authors.initials: JL
authors.lastname: Preston
authors.affiliation: Alberta Health Services, Calgary, Alberta, Canada.
authors.forename: M Sarah
authors.initials: MS
authors.lastname: Rose
authors.affiliation: Alberta Health Services, Calgary, Alberta, Canada.
authors.forename: Sheila
authors.initials: S
authors.lastname: McDonald
authors.affiliation: University of Calgary, Calgary, Alberta, Canada.
authors.forename: Suzanne
authors.initials: S
authors.lastname: Tough
mesh_terms: D002170:Canada; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007223:Infant; D007804:Language Development; D007805:Language Development Disorders / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology; D008137:Longitudinal Studies; D008297:Male; D011247:Pregnancy; D011446:Prospective Studies; D065840:Protective Factors; D012307:Risk Factors