Accurate Autism Screening at the 18-Month Well-Child Visit Requires Different Strategies than at 24 Months

J Autism Dev Disord. 2017 Oct;47(10):3296-3310. doi: 10.1007/s10803-017-3231-0.


Accuracy of autism screening using M-CHAT plus the follow-up interview (M-CHAT/F) for children screened positive at 18-months was compared to screening at 24-months. Formal ASD testing was criterion for a community sample of M-CHAT positive children (n = 98), positive predictive value (PPV) was 0.40 for the M-CHAT and 0.58 for the M-CHAT/F. MCHAT/F PPV was 0.69 among children 20+ months compared to 0.36 for <20 months. Multivariate analyses incorporating data from the Ages and Stages Questionnaire, MacArthur-Bates Communicative Development Inventory, M-CHAT and M-CHAT/F results, and M-CHAT items suggest language variables carry greatest relative importance in contributing to an age-based algorithm with potential to improve PPV for toddlers <20 months to the same level as observed in older toddlers.

Keywords: Autism screening; Developmental screening; M-CHAT; Toddler development.

MeSH terms

  • Age Factors
  • Algorithms
  • Autistic Disorder / diagnosis*
  • Autistic Disorder / psychology*
  • Child, Preschool
  • Female
  • Follow-Up Studies
  • Humans
  • Infant
  • Interview, Psychological / methods*
  • Interview, Psychological / standards
  • Male
  • Mass Screening / methods*
  • Mass Screening / standards
  • Physical Examination / methods*
  • Physical Examination / standards
  • Surveys and Questionnaires