Table 3.

Selected methods for autism diagnosis and categorisation

	Description	0–3 years	3–5 years	SA	Adult	Administration time (min)
Checklist or inventory
Screening method
Quantitative checklist for autism in toddlers29	Parent questionnaire, 25 questions	X	··	··	··	5–10
Modified checklist for autism in toddlers30	Questionnaire 23 questions	X	··	··	··	10
First year inventory31	Parent report 60 questions	X	··	··	··	NS
Early childhood inventory-432	Parent rating scale 108 items Teacher rating scale, 87 items	··	X	··	··	<20
Child symptom inventory-433	Parent rating scale 97 items, teacher rating scale 77 items	··	··	X	··	Variable
Social communication questionnaire34	Parent interview or questionnaire 40 items	··	X	X	··	10–15
Asperger’s syndrome diagnostic scale35	Parent or teacher rating scale 50 items	··	··	X	··	10–15
Krug Asperger diagnostic index36	Parent, caregiver, or teacher questionnaire 32 items	··	··	X	··	10–15
Autism spectrum quotient37	Parent questionnaire, for child, adolescent, and adult 50 questions	··	··	X	X	NS
Autism behaviour checklist38	Parent or teacher questionnaire 57 items	··	X	X	··	10–20
Pervasive developmental disorder rating scale39	Rating scale 51 items	X	X	··	··	NS
Pervasive developmental disorder in mental retardation scale40	Clinician and teacher observation instrument 12 items	··	X	X	··	10–20
Dimensional assessment
Developmental behaviour checklist,41 and developmental     behaviour checklist—early screen42	Questionnaire; 96 items and 17 items	X	X	··	··	10–15
Pervasive developmental disorder behaviour inventory43	Parent, caregiver, or teacher rating scale 8–10 subscales (124–188 items)	X	X	X	··	20–45
Aberrant behaviour checklist44	Parent rating scale 58 items	··	X	X	··	20–30
Child communication checklist45	Parent rating scale 70 items	··	X	X	··	5–15
Social responsiveness scale46	Parent and caregiver questionnaire 65 items	··	X	X	X	15–20
Repetitive behaviour scale—revised47	Parent and caregiver questionnaire 43 items	X	X	X	X	15–20
Social and communication disorders checklist48	Parent and caregiver rating scale 12 items	··	··	X	X	10–15
Structured interview
Diagnostic method
Parent interview for autism49	Parent interview 118 items	X	··	··	··	20–30
Diagnosis of social and communication disorder schedule50	Semistructured caregiver interview schedule 2–4 h administration, more than 300 items	··	X	X	··	180
Autism diagnostic interview—revised51	Semistructured, investigator-based interview for caregivers	X*	X	X	X	90–180
Diagnostic method, dimensional assessment
Developmental, dimensional, and diagnostic interview (3di)52	Caregiver computerised interview 183 items (demographics), 266 items (ASD related), 291 items (current mental state)	X	X	X	X	45–90
Observational measures
Screening method
Checklist for autism in toddlers53	Caregiver rating scale plus observations	X	··	··	··	10
Screening tool for autism in children aged 2 years54	Clinician observation 12 items	X	··	··	··	20†
Diagnostic method, dimensional assessment
Autism observation schedule for infants55	Clinician observation 18 item	X	··	··	··	20†
Autism diagnostic observation schedule—modules 1–456	Standardised observation method	X	X	X	X	40–60†
Diagnostic method
Childhood autism rating scale57	History and observation 15 items (Likert scale)	X	X	X	X	20–30

SA=school-aged children. NS=not specified. ASD=austistic spectrum disorder. X=appropriate method

^*Mental age older than 2 years.

^†Training needed to administer this method.