Table 2. Main model analyses examining the risk of childhood cerebral palsy by maternal immigration status (upper) and by immigrant World region of origin (lower), each compared to non-immigrants.

		Outcome of cerebral palsy up to age 4 years
			Hazard ratio (95% CI)
Analysis	Mother's World region of origin	Number of events(rate per 1000 [95% CI])	Unadjusted	Adjusted*
Comparing immigrant vs. non-immigrants	Non-immigrants (n = 566,668)	1089 (1.92 [1.81 to 2.04])	1.00 (referent)	1.00 (referent)
	Immigrant (n = 177,390)	257 (1.45 [1.28 to 1.64])	0.75 (0.66 to 0.86)	0.77 (0.67 to 0.88)
Comparing immigrants by their World region vs. non-immigrants	Non-immigrants (n = 566,668)	1089 (1.92 [1.81 to 2.04])	1.00 (referent)	1.00 (referent)
	Sub-Saharan Africa (n = 12,717)	23 (1.81 [1.21 to 2.71])	0.94 (0.62 to 1.42)	0.87 (0.57 to 1.32)
	South Asia (n = 56,316)	94 (1.67 [1.37 to 2.04])	0.87 (0.70 to 1.07)	0.84 (0.68 to 1.05)
	Caribbean (n = 10,899)	18 (1.65 [1.05 to 2.61])	0.86 (0.54 to 1.37)	0.58 (0.37 to 0.93)
	Hispanic America (n = 13,417)	22 (1.64 [1.09 to 2.48])	0.85 (0.56 to 1.30)	0.83 (0.54 to 1.27)
	Middle East and North Africa (n = 17,222)	28 (1.63 [1.13 to 2.35])	0.85 (0.58 to 1.23)	0.90 (0.61 to 1.32)
	Western Nations and Europe (n = 27,967)	37 (1.32 [0.96 to 1.82])	0.70 (0.50 to 0.96)	0.77 (0.55 to 1.06)
	East Asia and Pacific (n = 38,852)	35 (0.90 [0.65 to 1.25])	0.47 (0.34 to 0.66)	0.54 (0.39 to 0.77)

The period of observation starts at 28 days after birth and continues until age 4 years.

*Adjusted for maternal age, parity, neighbourhood income quintile, any pre-pregnancy or gestational diabetes mellitus, obesity, tobacco use, Caesarean delivery, fiscal year of delivery, number of physician visits between day 1 and day 140 of pregnancy, twin pregnancy, preterm birth before 32 weeks, preterm birth from 33 to 37 weeks, small for gestational age birthweight under the 10th percentile, and large for gestational age birthweight over the 90th percentile.

CI confidence interval.