Table 1.

Description of variables in analytic sample, Santiago, Chile, 2004

Continuous Birth Outcome Variable	N	Mean	SD	Min	Max
Weeks of gestational age at birth	56868	38.62	1.80	20	43
Weight at birth in grams	56900	3344.96	529.01	508	6060
Length at birth in cm	56873	49.54	2.51	30	61
Maternal Age at birth (years)	56965	27.86	6.68	11	51
Maternal Years of Education	56966	12.31	3.37	0	22
Continuous Census District Variable	N	Mean	SD	Min	Max
Number of domiciles per capita	56963	0.27	0.06	0.09	0.73
% domiciles connected to sewer	56963	25.17	3.92	8.03	50.16
ln(average total valuation/m2)	56900	10.78	0.88	8.16	14.88
% population non-indigenous	56963	96.65	1.58	90.71	99.32
% population with formal schooling	56963	98.64	0.67	95.99	99.88
% not unemployed and seeking work	56963	95.42	0.99	92.36	99.02
% population owners or employers	56963	1.91	1.19	0.15	9.78
% domiciles with concrete paving	56963	2.19	4.94	0.00	30.43
% domiciles with indoor plumbing	56963	25.20	3.91	8.03	50.16
% domiciles with indoor heating.	56963	21.22	4.84	6.52	36.03
Census District SES Score1	56894	0.00	1.00	-2.15	4.70
	In Full Sample			Ages 20+ Only2
Categorical Birth Outcome Variable	N	%		N	%
Male Sex of Newborn	56970	51.05		49771	51.19
Medical Attention at Birth	56970	99.96		49771	99.96
Mother Married at time of Birth	56970	53.31		49771	47.60
Preterm Deliver (< 37 wks)	56868	6.41		49674	6.29
Low Birth Weight (< 2500 g)	56900	4.94		49707	4.80
Preterm LBW (< 2500 g, <37 wks)	56802	3.33		49613	3.27
Very Low Birth Weight (< 1500 g)	56900	0.86		49707	0.86

1 based on principal components analysis of 10 census items

2 for comparison with Figure 1