Residential Greenness and Birth Outcomes: Evaluating the Influence of Spatially Correlated Built-Environment Factors

http://dx.doi.org/10.1289/ehp.1308049



Table 1. Characteristics of the Vancouver metropolitan area birth cohort [n (%) or mean ± SD] with complete data for greenness and built environment exposures, overall (n = 64,705) and according to NDVI quartiles.
Variable Entire cohort NDVI Q1
(< 0.18)
NDVI Q2
(0.18–0.23)
NDVI Q3
(0.23–0.29)
NDVI Q4
(≥ 0.29)
aBirth weight below the 10th percentile of the cohort, stratified by sex, for each week of gestation. b≥ 37 weeks of gestation, n = 61,286.
Study population (n) 64,705 15, 316 13,773 18,120 17,466
Birth outcomes          
Very preterm birth (< 30 weeks) 230 (0.4) 61 (0.4) 57 (0.4) 63 (0.4) 53 (0.3)
Moderately preterm birth (30–36 weeks) 3,189 (5.0) 824 (5.4) 715 (5.2) 892 (4.9) 758 (4.4)
SGAa [n (%)] 6,817 (10.5) 1,719 (11.2) 1,572 (11.4) 1,885 (10.4) 1,641 (9.4)
Birth weight (g) at full termb 3,483 ± 472 3,440 ± 464 3,456 ± 468 3,491 ± 473 3,532 ± 476
Covariates          
Female sex 31,341 (48.4) 7,494 (48.9) 6,657 (48.3) 8,707 (48.0) 8,483 (48.6)
Nulliparous 29,339 (45.3) 8,006 (52.3) 6,499 (47.2) 7,926 (43.7) 6,878 (39.4)
Maternal age (years)
≤ 19 957 (1.5) 235 (1.5) 189 (1.4) 289 (1.6) 244 (1.4)
20–29 23,760 (36.7) 5,623 (36.7) 5,213 (37.9) 6,910 (38.1) 6,014 (34.4)
30–34 23,981 (37.1) 5,698 (37.2) 5,013 (36.4) 6,734 (37.1) 6,536 (37.4)
35–40 13,383 (20.7) 3,111 (20.3) 2,815 (20.4) 3,540 (19.5) 3,917 (22.4)
≥ 40 2,624 (4.1) 649 (4.2) 543 (3.9) 677 (3.7) 755 (4.3)
Maternal smoking during pregnancy 4,184 (6.5) 909 (5.9) 742 (5.4) 1,213 (6.7) 1,320 (7.6)
First Nations status 395 (0.6) 146 (1.0) 82 (0.5) 85 (0.4) 95 (0.5)
Maternal education (census quartile)
1st quartile (lowest education) 14,412 (22.3) 3,568 (23.3) 3,298 (24.0) 4,332 (23.9) 2,809 (18.2)
2nd quartile 14,654 (22.7) 3,149 (20.6) 3,336 (24.2) 4,208 (23.2) 3,402 (22.0)
3rd quartile 17,669 (27.3) 3,690 (24.1) 3,815 (27.7) 5,152 (28.4) 4,450 (28.8)
4th quartile (highest education) 17,970 (27.8) 4,909 (32.1) 3,324 (24.1) 4,458 (24.6) 4,772 (30.9)
Income (census quintile)
1st quintile (lowest income) 13,815 (21.4) 5,823 (38.0) 3,603 (26.2) 2,929 (16.2) 1,450 (8.3)
2nd quintile 14,377 (22.2) 3,791 (24.8) 3,597 (26.1) 4,092 (22.6) 2,897 (16.6)
3rd quintile 13,666 (21.2) 2,413 (15.8) 3,012 (21.9) 4,326 (23.8) 3,915 (22.4)
4th quintile 12,524 (19.4) 1,753 (11.5) 2,095 (15.2) 4,086 (22.5) 4,590 (26.3)
5th quintile (highest income) 10,323 (16.0) 1,536 (10.0) 1,466 (10.6) 2,707 (14.9) 4,614 (26.4)
Change of address during pregnancy 21,990 (34.0) 5,129 (33.5) 5,649 (41.0) 6,685 (36.8) 4,389 (28.4)