Table 2.

Characteristics of the Study Population

		All Children Born in Sweden 1973–1985 (N = 1172879)
		No diagnose of nonaffective psychosisa (n = 1168 241, 99.6%)	Diagnose of nonaffective psychosisa (n = 4638, 0.4%)
		n (%)	n	%
Male		599673 (51.3)	2 728	58.8
Urban birthb		162793 (13.9)	835	18.0
Born December–May		609938 (52.2)	2 495	53.8
Parental age ≥35	Maternal	94928 (8.1)	466	10.0
	Paternal	213553 (18.3)	1 031	22.2
Parental psychiatric illnessc	Maternal	90278 (7.7)	972	21.0
	Paternal	102304 (8.8)	928	20.0
Parental immigrationd	Maternal	108559 (9.3)	761	16.4
	Paternal	114204 (9.8)	801	17.3
Socioeconomic status	Parent unemployed	38080 (3.2)	358	7.7
	Household receiving social welfare benefits	407759 (34.9)	2 138	46.1
Hospital admission with infectione	First year	66955 (5.7)	304	6.6
	1–4 y	133282 (11.4)	603	13.0
	5–9 y	57130 (4.9)	297	6.4
	10–13 y	33395 (2.8)	163	3.5
	0–13 y	246510 (21.1)	1140	24.6
Inpatient care with other diagnosesf		399014 (34.2)	1785	38.5
Percent with ≥4 hospital admissions with infectione during childhood, 0–13 y		0.75	1.27

^aICD-10 F20-29.

^b>200 000 habitants 1980.

^cICD-10 F00-99.

^dBorn outside Sweden.

^eDiagnoses (s upplementary table 1).

^fHospital admission with all diagnoses except a diagnosis of infection or a psychiatric diagnosis.