Table 1.

Studies using the Infant-Toddler Checklist as a screener in young children

Autism spectrum disorder + communication delays vs. typical development
Study	Age (months)	Sample Size	Recruitment Groups	Outcome Groups	Specificity % (95% CI)	Specificity % (95% CI)	PPV % (95% CI)	NPV % (95% CI)
Pierce et al. (2011)	12	10479	General	ASD, LD, DD, other	-	-	75	-
Wetherby et al. (2004)	< 24	3026	General	ASD, DD, TD	89	89	94	80
Wetherby et al. (2008)	18	5385	General	ASD, LD, TD	-	-	77	90
	24						79	88
Autism spectrum disorder only vs. typical development
Wetherby et al. (2004)	< 24	3026	General	ASD, TD	94	89	90	94
Wetherby et al. (2008)	18-24	5385	General	ASD, TD	93	-	-	-
Oosterling et al. (2009)	8-44	238	High-risk1	ASD, Non-ASD	71	59	78	50
Dudova et al. (2014)	24	155	<1500g birth weight	ASD, TD	85	85	38	98

Note. ASD = Autism spectrum disorder. TD = typical development. DD = developmental delay. LD = language delay.

¹High-risk if scored positive on the Early Screening of Autistic Traits (ESAT) or due to clinical concern.