Table 2.

Crude and adjusted analyses of effects of independent variables on prevalence of male adolescents’ early sexual initiation. Pelotas, Southern Brazil, 1982 to 2004-5

Variable	Crude analysis			Adjusted analysis^*
Variable	PR	95% CI	p	PR	95% CI	p
Skin color			<0.001^**			<0.001^**
White	1	-		1	-
Black or mixed	1.65	1.38;1.98		1.48	1.23;1.79
Family income - 1982 (MMW)			<0.001^***			<0.001^***
≤1.0	4.20	2.01;8.79		3.57	1.70;7.50
1.1 to 3.0	3.82	1.85;7.92		3.48	1.68;7.22
3.1 to 6.0	2.40	1.13;5.13		2.32	1.08;4.95
6.1 to 10.0	2.45	1.06;5.66		2.42	1.05;5.60
>10.0	1	-		1	-
Change in income (1982 → 2004-5)			<0.001^***			<0.001^***
Always poor	1.95	1.56;2.43		1.72	1.36;2.19
Not poor → poor	1.54	1.21;1.97		1.51	1.18;1.93
Poor → not poor	1.75	1.39;2.20		1.54	1.22;1.96
Never poor	1	-		1	-
Adolescent’s level of education (years)			<0.001^***			<0.001^***
0-4	4.39	2.91;6.63		3.15	1.95;5.08
5-8	2.72	1.84;4.04		2.02	1.29;3.17
9-11	1.58	1.06;2.36		1.25	0.80;1.94
≥12	1	-		1	-

MMW: Monthly minimum wage.

Variables on the first level (ethnicity and family income in 1982) were adjusted among themselves and remained in the analysis model, if p<0.2. Change in income was adjusted for ethnicity; adolescent’s level of education was adjusted for ethnicity and family income.

^**

Wald test for heterogeneity.

^***

Wald test for linear trend.