Table 3.

Clinical and developmental characteristics of children with ASD, delayed or typical development^*

	ASD (n=303)		DD (n=63)		TD (n=163)
Characteristic	n	%	n	%	n	%	P value
History of seizures
Febrile seizure	18	6.6	2	3.4	3	1.9	.06
Non-febrile seizures	18	6.6	12	20.7	0	0.0	<.0001
Any seizures	28	10.3	12	20.7	3	1.9	<.0001
Current use of medications or supplements for:§
Allergic disorders	24	8.9	3	5.2	10	6.4	.48
Central nervous system	22	8.1	11	19.0	1	0.6	<.0001
Endocrine system	1	0.4	3	5.2	2	1.3	.04
Gastrointestinal tract	11	4.1	5	8.6	2	1.3	.04
Respiratory tract	14	5.2	10	17.2	12	7.7	.01
Dietary supplements	46	17.0	9	15.5	7	4.5	.0002
Any medications/supplements	93	34.3	28	48.3	26	16.7	<.0001
Current gastrointestinal symptoms
Gaseousness/bloating	29	10.5	3	4.8	3	2.0	.0014
Diarrhea	44	14.8	5	7.9	2	1.3	<.0001
Constipation	42	14.1	10	15.9	5	3.2	.0002
Any gastrointestinal symptoms	91	30.4	13	20.6	8	5.1	<.0001
Cognitive function, ≤70	237	79.8	60	95.2	0	0.0	<.0001
Adaptive function, <70	220	73.1	44	69.8	0	0.0	<.0001
Combined low cognitive/adaptive function	193	65.4	41	65.1	0	0.0	<.0001
Normal IQ†	39	13.2	0	0.0	163	100	<.0001

^*Data are given as percentage of each group unless otherwise indicated. Numbers may not add up to total due to sporadic missing data. Percentages may not total 100 because of rounding. P-values were calculated using likelihood ratio Chi-square test.

^§excluded medications for transient infections/conditions; also excluded multivitamins and fluoride

^†Normal intelligence is defined as Mullen Scales of Early Learning composite score >70 and Vineland Adaptive Behavior Scales composite score ≥70