Evidence-based assessment/Instruments/Modified checklist for autism in toddlers

The Modified Checklist for Autism in Toddlers (M-CHAT) is a psychological questionnaire that evaluates risk for autism spectrum disorder in children ages 16–30 months. The 20-question test is filled out by the parent, and a follow-up portion is available for children who are classified as medium- to high-risk for autism spectrum disorder. Children who score in the medium to high-risk zone may not necessarily meet criteria for a diagnosis. The checklist is designed so that primary care physicians can interpret it immediately and easily.

Scoring and interpretation
The first section of the M-CHAT identifies 20 behavioral characteristics of the autism spectrum and asks if the child has experienced any of them. If the parent reports a sufficient number of characteristics for the child in this section, a follow-up form outlining specific questions pertaining to that characteristic would be administered by the researcher. It does not have to be completed for characteristics the child does not possess. The follow-up form asks questions based on a flow-chart format, ultimately categorizing the child as “pass” or “fail” for each characteristic.

Item breakdown
For the first section, a response of “no” for all questions except 2, 5, and 12 indicate risk of autism spectrum disorder. A response of “yes” indicates ASD risk for the remaining three questions.

For the follow-up section, the flowchart format will direct the researcher in determining whether or not the child’s behavior is suggestive of ASD. If the parent describes abnormal behavior, the child will fail that item.

Interpretation of subscale scores
A total score of 2 and below on the first part of the M-CHAT indicate low autism risk, but children under 24 months should nevertheless be tested again after their second birthday. A total score of 3-7 indicates medium risk and prompts administration of the follow-up form. Even with the follow-up form, some children who fail the M-CHAT will not be diagnosed with ASD, but may still be at risk for other developmental disorders. A total score of 8 or higher indicates high autism risk, and the follow-up form can be bypassed for immediate referral to a professional for diagnosis.

The follow-up form has its own scaling. If the child fails at least two items, the child should be referred to a professional for diagnosis.