Table 1

Examples of findings from systematic reviews of recent studies on childhood/youth prevalence of autism

Review		No. of studies	Publication dates of studies	Median prevalence/1000	Range/1000
Autistic disorder
French et al., 20134	Autistic disorder	26	2000–2011	2.2	0.8–9.4
French et al., 20134	Asperger syndrome*	13	1998–2011	2.1	0.5–2.8
Elsabbagh et al., 20125	Northern European	16	2000–2008	1.9	0.7–3.9
	Western Pacific	12	2000–2011	1.2	0.3–9.4
	South East Asia/East Mediterranean	1	-	-	-
	Americas	7	2001–2010	2.2	1.1–4.0
	Overall			1.7	0.3–9.4
Tsai, 20146		43	2001–2013	2.8	0.3–19.0
Pervasive developmental disorder
French et al., 20134		34	2000–2011	6.2	0.6–26.4
Elsabbagh et al., 20125	Northern Europe	14	2000–2011	6.2	3.0–11.6
	Western Pacific	4	2004–2011	-	1.6–19.0
	South East Asia/East Mediterranean	4	2007–2012	-	0.1–10.7
	Americas	13	2001–2010	6.5	1.3–11.0
	Overall			6.2	0.1–19.0
Tsai, 20146		61	2000–2014	7.0	0.2–26.4
Adak and Halder, 20177		25	2005–2015	9.2	0.7–26.4