Table 1.

Characteristics of the study population.

	Intellectual Disability(n = 43176)	No Intellectual Disability(n = 215733)
Median age at entry (years)*	24 (3–54)	24 (3–54)
Female n (%)	17429 (40.4)	87836 (40.7)
Children (age 1–17 y at entry)	15470	76700
Median age at entry (years)*	7.0 (1.0–15.0)	7.0 (1.0–15.0)
Female n (%)	5602 (36.2)	27905 (36.4)
Adults (age ≥18y at entry)	27706	139033
Median age at entry (years)*	35.0 (21.0–60.0)	35.0 (21.0–60.0)
Female n (%)	11827 (42.7)	59931 (43.1)

^⁎10th-90th centile