From the Guidelines
The most effective screening tool for autism in young children is the Modified Checklist for Autism in Toddlers (M-CHAT), which should be used for children 16-30 months old. This tool assesses social communication, repetitive behaviors, and developmental milestones, and asks about behaviors like pointing, responding to name, and social interest 1. The M-CHAT has been evaluated internationally and in multiple languages, and has been shown to have a high positive predictive value (PPV) for autism spectrum disorder (ASD) in children aged 24-30 months 1.
Some key points to consider when screening for autism include:
- The M-CHAT is a parent-rated scale, and a positive finding leads to a follow-up interview, which, if positive, should lead to a full diagnostic workup for ASD 1
- The screening process assesses communication skills, joint attention, repetitive movement, and pretend play 1
- Early screening is valuable because early intervention can significantly improve outcomes for children with autism 1
- Screening tools identify potential concerns but don't provide a diagnosis - formal evaluation by specialists is necessary for diagnosis 1
It's also important to note that the USPSTF concludes that there is insufficient evidence to assess the balance of benefits and harms of screening for ASD in young children for whom no concerns of ASD have been raised 1. However, the American Academy of Pediatrics recommends screening for ASD in children aged 18 to 24 months 1.
In terms of other screening tools, the Autism Spectrum Quotient (AQ) is used for older children and adults, focusing on social skills, communication patterns, and attention to detail, and the Social Communication Questionnaire (SCQ) evaluates communication and social interaction in individuals over age 4 1. Healthcare providers may also use the Autism Diagnostic Observation Schedule (ADOS) or the Autism Diagnostic Interview-Revised (ADI-R), which involve structured observations and parent interviews 1.
Overall, the M-CHAT is a useful tool for screening for autism in young children, and should be used as part of a comprehensive screening program.
From the Research
Screening Tools for Autism
- The Modified Checklist for Autism in Toddlers (M-CHAT) is a widely used screening tool for autism spectrum disorder (ASD) in young children 2, 3, 4, 5, 6.
- The M-CHAT consists of 23 questions that address various aspects of child development, including social relatedness, joint attention, and pretend play 2, 3, 6.
- The Checklist for Autism in Toddlers (CHAT) is another screening tool that has been used to identify autism in young children, but it has been found to have lower sensitivity and specificity compared to the M-CHAT 2, 3, 6.
- The CHAT-23 is a modified version of the CHAT that combines the M-CHAT with the observational section of the CHAT, and has been found to have high sensitivity and specificity in identifying autism in Chinese children 2.
Key Questions for Autism Screening
- The M-CHAT includes several key questions that are highly predictive of autism, including:
- Does your child imitate you? (e.g., you make a face, will your child imitate it?) 2.
- Does your child ever pretend, for example, to talk on the phone or take care of dolls, or pretend other things? 2.
- Does your child ever use his/her index finger to point, to indicate interest in something? 2.
- Does your child look at your face to check your reaction when faced with something unfamiliar? 2.
- Does your child ever bring objects over to you (parent) to show you something? 2.
- If you point at a toy across the room, does your child look at it? 2.
- Does your child take an interest in other children? 2.
Accuracy of Autism Screening Tools
- The M-CHAT has been found to have a pooled sensitivity of 0.83 and specificity of 0.51 in identifying ASD in high-risk children 4.
- The M-CHAT-R/F has been found to have a pooled positive predictive value of 57.7% and negative predictive value of 72.5% in identifying ASD 5.
- The accuracy of autism screening tools can vary depending on the population being screened and the age of the child at the time of screening 4, 5.