A 3-year-old does not speak, avoids eye contact, lines up toys repetitively, and becomes severely distressed when his routine is changed. His pediatrician suspects ASD. The single most important standardized diagnostic screening tool validated for this age in primary care is:
- A Modified Checklist for Autism in Toddlers — Revised (M-CHAT-R/F) ✓
- B Childhood Autism Rating Scale (CARS)
- C Autism Diagnostic Observation Schedule (ADOS-2)
- D Vineland Adaptive Behavior Scales
Correct answer: A. Modified Checklist for Autism in Toddlers — Revised (M-CHAT-R/F)
Explanation
The M-CHAT-R/F (Modified Checklist for Autism in Toddlers — Revised with Follow-up) is a validated Level 1 screening tool for ASD in toddlers aged 16-30 months in primary care settings — given to parents as a 20-item questionnaire. ADOS-2 (Autism Diagnostic Observation Schedule) is the gold standard diagnostic assessment but requires trained clinicians and is a Level 2 diagnostic, not initial screening. CARS is a clinician-rated scale. Vineland assesses adaptive behavior across ages.
Reference: Kaplan & Sadock's Synopsis of Psychiatry, 11th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.