title: Large-scale use of the modified checklist for autism in low-risk toddlers.
abstract: OBJECTIVE
  The purpose of the study was to examine use of the Modified Checklist for Autism in Toddlers (M-CHAT) as an autism-specific screening instrument in a large, geographically diverse pediatrics-based sample.
  
  
  METHODS
  The M-CHAT and the M-CHAT Follow-Up (M-CHAT/F) were used to screen 18,989 toddlers at pediatric well-child visits in 2 US geographic regions. Pediatricians directly referred children to ascertain potential missed screening cases. Screen-positive children received the M-CHAT/F; children who continued to screen positive after the M-CHAT/F received a diagnostic evaluation.
  
  
  RESULTS
  Results indicated that 54% of children who screened positive on the M-CHAT and M-CHAT/F presented with an autism spectrum disorder (ASD), and 98% presented with clinically significant developmental concerns warranting intervention. An M-CHAT total score cutoff of ≥3 identifies nearly all screen-positive cases, and for ease of scoring the use of only the M-CHAT total score cutoff is recommended. An M-CHAT total score of 7 serves as an appropriate clinical cutoff, and providers can bypass the M-CHAT/F and refer immediately to evaluation and intervention if a child obtains a score of ≥7.
  
  
  CONCLUSIONS
  This study provides empirical support for the utility of population screening for ASD with the use of the M-CHAT in a primary care setting. Results suggest that the M-CHAT continues to be an effective screening instrument for ASD when the 2-step screening process is used. The M-CHAT is widely used at pediatric offices, and this study provides updated results to facilitate use and scoring of the M-CHAT by clinical providers.
authors.affiliation: Department of Psychiatry, University of California, San Diego, San Diego, California, USA. cchlebowski@ucsd.edu
authors.forename: Colby
authors.initials: C
authors.lastname: Chlebowski
authors.forename: Diana L
authors.initials: DL
authors.lastname: Robins
authors.forename: Marianne L
authors.initials: ML
authors.lastname: Barton
authors.forename: Deborah
authors.initials: D
authors.lastname: Fein
mesh_terms: D001321:Autistic Disorder / Q000175:diagnosis*; D057189:Checklist; D002659:Child Development Disorders, Pervasive / Q000175:diagnosis; D002662:Child Health Services; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008403:Mass Screening / Q000379:methods*; D011237:Predictive Value of Tests; D011320:Primary Health Care; D012306:Risk