Table 2.

Febrile and afebrile seizure rates for up to 3 years of age, according to birth findings

	N	Prevalence of seizure, % (95% CI)	Prevalence of febrile seizure, % (95% CI)	Prevalence of afebrile seizure, % (95% CI)	Prevalence of seizure without known cause, % (95% CI)
Total	74 017	12.1 (11.9 to 12.4)	9.1 (8.9 to 9.3)	0.9 (0.8 to 1.0)	2.1 (2.0 to 2.2)
Sex
Male	37 684	12.8 (12.5 to 13.2)	9.9 (9.6 to 10.2)	0.9 (0.8 to 1.0)	2.1 (1.9 to 2.2)
Female	36 240	11.4 (11.1 to 11.8)	8.3 (8.0 to 8.6)	0.9 (0.8 to 1.0)	2.2 (2.0 to 2.3)
Gestational age at birth, weeks
22–27	134	15.7 (10.5 to 22.8)	11.2 (6.9 to 17.7)	2.2 (0.8 to 6.4)	2.2 (0.8 to 6.4)
28–33	766	14.6 (12.4 to 17.7)	11.8 (9.7 to 14.5)	1.3 (0.7 to 2.4)	1.6 (1.0 to 3.0)
34–36	3566	13.2 (12.2 to 14.4)	10.5 (9.5 to 11.5)	1.1 (0.8 to 1.5)	1.6 (1.3 to 2.1)
37–41	69 315	12.1 (11.8 to 12.3)	9.0 (8.8 to 9.2)	0.9 (0.8 to 1.0)	2.2 (2.1 to 2.3)
42–43	236	12.3 (9.0 to 16.4)	10.6 (7.6 to 14.6)	0.3 (0.1 to 1.9)	1.3 (0.5 to 3.4)
Birth weight, g
<1500	454	15.6 (12.6 to 19.3)	12.3 (9.6 to 15.7)	1.8 (0.9 to 3.4)	1.5 (0.8 to 3.2)
1500–2499	6525	13.0 (12.2 to 13.8)	10.0 (9.3 to 10.7)	1.1 (8.6 to 13.7)	1.9 (1.6 to 2.3)
2500+	66 934	12.0 (11.8 to 12.3)	9.0 (8.8 to 9.2)	0.9 (0.8 to 1.0)	2.1 (2.0 to 2.3)
Birth length, cm
<40	392	17.4 (13.9 to 21.4)	14.0 (10.9 to 17.8)	1.8 (0.9 to 3.6)	1.5 (0.7 to 3.3)
40–44.9	2693	12.7 (11.5 to 14.0)	10.0 (9.0 to 11.2)	1.1 (0.8 to 1.5)	1.6 (1.2 to 2.1)
45–49.9	46 935	12.2 (11.9 to 12.5)	9.1 (8.8 to 9.4)	0.9 (0.8 to 1.0)	2.2 (2.1 to 2.3)
50+	20 490	12.0 (11.5 to 12.4)	9.1 (8.7 to 9.5)	0.9 (0.8 to 1.0)	2.1 (1.9 to 2.3)
Head circumference at birth, cm
<25	156	17.3 (12.2 to 24.0)	14.7 (10.0 to 21.2)	1.9 (0.7 to 5.5)	0.6 (1.1 to 3.5)
25–29.9	940	14.9 (12.8 to 17.3)	11.2 (9.3 to 13.3)	1.4 (0.8 to 2.4)	2.3 (1.6 to 3.5)
30–32.9	22 199	12.4 (12.0 to 12.9)	9.2 (8.9 to 9.6)	1.0 (0.9 to 1.2)	2.2 (2.0 to 2.4)
33+	46 693	12.0 (11.7 to 12.3)	9.1 (8.8 to 9.3)	0.9 (0.8 to 1.0)	2.1 (2.0 to 2.2)