Table 1 Developmental and behavioral assessment tools used to characterize the features of children with autism.

Modified Checklist for Autism Toddlers-Revised/Follow-up (M-CHAT–R/F)¹⁰⁹

16–30 months

It is a two-stage parent-report screening tool. Items 2, 5, and 12 are critical if they are answered ‘yes,’. When the rest of the items are answered ‘no,’ the risk for ASD is high.

Childhood Autism Rating Scale (CARS)^110,111

Two years and above

The diagnostic tool consists of 14 domains assessing behaviors associated with ASD, with a 15th domain rating general impressions of ASD. Each domain is scored on a scale ranging from one to four; higher scores are associated with a higher level of impairment.

Autism Diagnostic Observation Schedule (ADOS)³⁶

12 months through adulthood

Consist of a series of structured and semi-structured tasks that involve social interaction between the examiner and the person under assessment. This assessment comprises of four modules differing in developmental and language levels, ranging from nonverbal to verbally-fluent.

Autism Diagnostic Inventory-Revised (ADI-R)³⁷

The mental age of about 18 months to adulthood

It is a standardized semi-structured clinical interview for caregivers of children and adults. The interview contains 93 items and focuses on behavior in three content areas: quality of social interaction; communication and language and repetitive, restricted, and stereotyped interests and behavior.

Mullen Scale of Early Learning (MSEL)^39,112.

Two days to 69 months

It is an assessment battery designed to measure development in infants and preschoolers. 124 items measure specific domains, including gross motor functions, visual reception, fine motor, and receptive and expressive language skills.

Social Communication Questionnaire (SCQ)⁴⁰

The mental age of 2 years and above

It is 40 items, yes or no, parent-report screening measure mainly focuses on the items relating to ASD symptomology primarily observed by a caregiver.