Table 2.

Unadjusted and adjusted analysis of the association between individual, maternal, and pregnancy-related variables and conviction for violent delinquency up to age 25 years among females from the 1982 Pelotas Birth Cohort

		Lifetime conviction of violent delinquency
		Unadjusted			Adjusteda
Level	Independent variables	n	CI%	CIR [95% CI]	Pb	CIR [95% CI]	Pb
1	Mother's skin colour				0.05		0.05
	White	2077	0.8%	1.0 Reference		1.0 Reference
	Black or mixed	431	1.9%	2.3 [1.0, 5.2]		2.3 [1.08, 5.2]
2	Mother's age (years)				0.001		0.01
	<20	374	2.7%	3.8 [1.7, 8.4]		2.9 [1.3, 6.4]
	≥20	2134	0.7%	1.0 Reference		1.0 Reference
	Mother's marital status				0.4		0.9
	With husband or partner	2323	0.9%	1.0 Reference		1.0 Reference
	Without husband or partner	184	1.6%	1.7 [0.5, 5.7]		1.1 [0.3, 3.4]
	Family income (no. of minimum wages)				<0.001c		0.01c
	≤1	503	1.8%	14.4 [1.8, 113.5]		9.2 [1.1, 74.4]
	1.1–3	1186	1.3%	10.2 [1.4, 77.1]		7.9 [1.1, 59.6]
	3.1–6	806	0.1%	1.0 Reference		1.0 Reference
	Smoking during pregnancy				0.9		0.6
	No	1631	1.0%	1.0 Reference		1.0 Reference
	Yes	878	1.0%	1.0 [0.5, 2.4]		0.8 [0.4, 1.8]
3	Obstetric complications				0.9		0.8
	No	2304	1.0%	1.0 Reference		1.0 Reference
	Yes	205	1.0%	1.0 [0.2, 4.1]		1.2 [0.3, 5.1]
	Number of younger siblings				1.0c		0.6c
	0	1554	1.0%	1.0 Reference		1.0 Reference
	1	564	0.9%	0.9 [0.3, 2.3]		0.7 [0.3, 1.8]
	≥2	60	1.7%	1.6 [0.2, 12.0]		1.1 [0.1, 8.5]
	Number of older siblings				1.0c		0.2c
	0	912	1.0%	1.0 Reference		1.0 Reference
	1	658	1.1%	1.1 [0.4, 2.9]		1.7 [0.6, 4.6]
	≥2	608	1.0%	1.0 [0.4, 2.8]		1.9 [0.6, 5.7]
4A	Duration of partial breast feeding (months)				0.6c		0.5c,d
	<1	479	0.8%	1.0 Reference		1.0 Reference
	1–2.9	640	1.2%	1.5 [0.5, 4.9]		1.4 [0.4, 4.6]
	3–5.9	562	0.5%	0.6 [0.1, 2.8]		0.7 [0.2, 3.0]
	6–8.9	216	0.9%	1.1 [0.2, 6.0]		1.3 [0.3, 6.8]
	9–11.9	90	2.2%	2.7 [0.5, 14.3]		3.0 [0.6, 15.6]
	≥12	401	1.2%	1.5 [0.4, 5.5]		1.4 [0.4, 5.2]
4B	Duration of total breast feeding (months)				0.5c		0.7c,e
	<1	532	1.1%	1.0 Reference		1.0 Reference
	1–1.9	304	0.3%	0.3 [0.0, 2.4]		0.3 [0.0, 2.4]
	2–2.9	483	1.9%	1.7 [0.6, 4.6]		1.8 [0.6, 5.0]
	3–3.9	646	0.6%	0.6 [0.2, 1.9]		0.6 [0.2, 2.2]
	≥4	301	0.7%	0.6 [0.1, 2.9]		0.6 [0.1, 3.0]
	Total	2509	1.0%

^aAdjusted for all variables in the same level or in higher levels with P< 0.2.

^bWald test for heterogeneity.

^cWald test for linear trend.

^dModel fitted with partial breast feeding as dependent variable.

^eModel fitted with predominant breast feeding as dependent variable.

CI, confidence interval; CI%, cumulative incidence; CIR, cumulative incidence ratio.