Table 3. Confirmation of autism spectrum disorder diagnosis, with and without intellectual disability, by sex and age, according to case-notes in a random sample of 177 cases in the Stockholm Youth Cohort.

	All ASD				ASD without intellectual disability				ASD with intellectual disability
	N	Nc (%)	95% CI	p-value	N	Nc (%)	95% CI	p-value	N	Nc (%)	95% CI	p-value
Overall	177	170 (96.0)	92.0–98.4	-	87	77 (88.5)	79.9–94.4	-	90	68 (75.6)	65.4–84.0	-
Sex				0.55				0.22				0.01
Male	121	115 (95.0)	89.5–98.2		59	50 (84.7)	73.0–92.8		62	42 (67.7)	54.7–79.1
Female	56	55 (98.2)	90.4–100.0		28	27 (96.4)	81.6–99.9		28	26 (92.9)	76.5–99.1
Age (years)				0.13				0.30				0.88
4–6	-	-	-
7–12	69	65 (94.2)	85.9–98.4		28	23 (82.1)	63.1–93.9		41	32 (76.5)	62.4–89.4
13–17	63	62 (98.4)	91.5–99.7		36	34 (94.4)	81.3–99.3		27	20 (82.1)	53.7–88.9
18–23	45	43 (95.6)	84.9–99.5		23	20 (87.0)	66.4–97.2		22	16 (67.9)	49.8–89.3

Nc – No. of confirmed cases.