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. Author manuscript; available in PMC: 2024 Mar 6.
Published in final edited form as: Health Place. 2013 Oct 9;24:190–195. doi: 10.1016/j.healthplace.2013.09.016

Table 3.

Odds ratios for preterm birth per inter-quartile range increase in NDVI exposure (four hospitals in Southern California, 1997–2006).

NDVI within 50 m buffers
 NDVI within 100 m buffers
 NDVI within 150 m buffers
Odds ratio per IQRc in NDVI exposure 95% Confidence interval p Odds ratio per IQRc in NDVI exposure 95% Confidence interval p Odds ratio per IQRc in NDVI exposure 95% Confidence interval p
Base modela 0.988 (0.970, 1.006) 0.17 0.978 (0.953, 1.005) 0.11 0.985 (0.972, 0.997) 0.02
Base modela, further adjusted for NOxb 0.984 (0.972, 0.996) 0.01 0.976 (0.954, 0.999) 0.04 0.983 (0.973, 0.992) < 0.01
Base modela, further adjusted for PM10b 0.988 (0.970, 1.006) 0.17 0.979 (0.952, 1.005) 0.12 0.985 (0.972, 0.998) 0.03
Base modela, further adjusted for PM2.5b 0.989 (0.973, 1.006) 0.21 0.977 (0.951,1.004) 0.10 0.987 (0.972, 1.002) 0.09
Base modela, further adjusted for O3b 0.990 (0.972, 1.008) 0.27 0.980 (0.955, 1.006) 0.13 0.986 (0.974, 0.998) 0.02
Base modela, further adjusted for COb 0.982 (0.972, 0.992) < - 0.01 0.975 (0.954, 0.997) 0.03 0.981 (0.973, 0.990) < 0.01
Base modela, further adjusted for traffic density within 50 m 0.998 (0.970, 1.027) 0.91 0.984 (0.954, 1.015) 0.31 0.990 (0.974,1.006) 0.20
Base modela, further adjusted for traffic density within 150 m 0.994 (0.969, 1.019) 0.64 0.983 (0.952, 1.015) 0.29 0.988 (0.973, 1.005) 0.16
Base modela, further adjusted for traffic density within 300 m 0.989 (0.969, 1.010) 0.31 0.980 (0.950, 1.010) 0.18 0.986 (0.970,1.002) 0.09
Base modela, further adjusted for CALINE4 NOxb 0.984 (0.961, 1.007) 0.17 0.977 (0.949, 1.006) 0.13 0.984 (0.967,1.000) 0.05
a

Generalized estimating equations model with logit link function including NDVI, maternal age and maternal age squared, poverty and poverty squared, insurance status, race/ethnicity, parity and pyelonephritis as dependent variables.

b

NOx: nitrogen oxides, PM10: particulate matter of less than 10 μm, PM2.5: particulate matter of less than 2.5 μm, O3: ozone, CO: carbon monoxide. All pollutants were measured my monitoring stations, except CALINE4 NOx that were local traffic-generated NOx concentrations estimated using the CALINE4 dispersion model.

c

IQR stands for inter-quartile range. The inter-quartile range increase in NDVI exposure is 0.109 for 50 m buffers, 0.121 for 100 m buffer and 0.131 for 150 m buffers.