Table 1.

Meta-analytic perspective showing adjusted prevalence ratios (95% confidence limits).

ASD subclassification	Kalkbrenner et al.	Lee et al.	Combineda
ASD without co-occuring intellectual disabilities	1.14 (0.08, 1.47)	1.13 (0.95, 1.25)	1.13 (1.03, 1.24)
ASD with co-occuring intellectual disabilities	0.72 (0.53, 0.98)	0.91 (0.78, 1.06)	0.87 (0.76, 1.00)
aData were combined using the EpiSheet tool (Rothman 2011) following the method of Fleiss (1993).