Skip to main content

Table 1 Statistics for the means of the target and individual-level variable across Census tracts

From: Spatial variability of the effect of air pollution on term birth weight: evaluating influential factors using Bayesian hierarchical models

Type

Variable

Category

Mean

Median

Inter quartile range (IQR)a

Target variable

Term birth weight (g)

 

3393

3392

58 (3363,3421)

Pollution indicator

Spatiotemporal NO2 (ppb)b

 

25.00

24.14

11.43 (18.74, 30.17)

Spatiotemporal NOx (ppb)c

 

17.32

26.31

31.32 (15.48, 46.80)

Individual- level variable

NDVI

 

0.26

0.25

0.09 (0.21, 0.30)

Maternal age

 

28.8

28.1

4.1 (26.7, 30.8)

Length of gestation

 

277

276

12 (271,283)

Infant gender (percentage)

Male

49 %

49 %

6 % (46–52 %)

Female

51 %

51 %

6 % (48–54 %)

Race/ethnicity (percentage)

Hispanic

54 %

57 %

57 % (26–83 %)

White

24 %

12 %

43 % (2–45 %)

Black

6 %

3 %

5 % (0.8–6 %)

Asian

13 %

8 %

14 % (2–16 %)

Others

2 %

1 %

2 % (1–3 %)

Maternal educational level (percentage)

Less than 8th grade

10 %

8 %

15 % (1–16 %)

9th grade to high school

42 %

47 %

36 % (24–60 %)

Less than 4 years of college

29 %

20 %

43 % (6–49 %)

4+ of college

19 %

19 %

11 % (13–24 %)

  1. aIQR for the mean (continuous variables) or percentage (categorical variables);
  2. bEstimates of NO2 by the spatiotemporal model; cEstimates of NOx by the spatiotemporal model