From: Urban–rural disparity in the relationship between ambient air pollution and preterm birth
Variable | OR (95% CI) | |||
---|---|---|---|---|
Hubei | East | Middle | West | |
Minority (ref: Han) | 1.04 (0.93–1.16) | 0.99 (0.66–1.49) | 1.26 (0.88–1.80) | 0.95 (0.84–1.08) |
Age (ref: 25–29) | ||||
< 20 | 1.32 (1.18–1.48)* | 1.20 (1.01–1.44)* | 1.38 (1.13–1.69)* | 1.51 (1.21–1.88)* |
20–24 | 0.97 (0.93–1.02) | 0.93 (0.87–0.99)* | 0.96 (0.89–1.04) | 1.18 (1.06–1.33)* |
30–34 | 1.25 (1.19–1.32)* | 1.17 (1.09–1.26)* | 1.38 (1.26–1.50)* | 1.33 (1.17–1.51)* |
≥ 35 | 1.86 (1.75–1.98)* | 1.84 (1.69–2.00)* | 1.84 (1.64–2.07)* | 1.94 (1.68–2.24)* |
Education (ref: secondary) | ||||
Elementary | 0.97 (0.92–1.02) | 0.94 (0.88–1.01) | 0.96 (0.87–1.05) | 1.08 (0.96–1.22) |
Tertiary | 0.98 (0.91–1.06) | 0.95 (0.87–1.05) | 0.95 (0.80–1.14) | 1.26 (1.01–1.59)* |
Regular health checks (ref: check < 5) | 0.89 (0.83–0.95)* | 0.84 (0.77–0.91)* | 0.91 (0.78–1.08) | 1.22 (0.95–1.56) |
Firstborn (ref: non–firstborn) | 1.04 (0.99–1.09) | 0.98 (0.92–1.04) | 1.22 (1.12–1.33)* | 0.98 (0.89–1.09) |
Female (ref: male) | 0.79 (0.76–0.82)* | 0.78 (0.74–0.82)* | 0.79 (0.75–0.85)* | 0.84 (0.77–0.92)* |
Income | 1.03 (0.96–1.10) | 0.96 (0.86–1.08) | 0.91 (0.77–1.07) | 0.94 (0.57–1.52) |
Income ^2 | 1.04 (1.01–1.07)* | 1.02 (0.98–1.06) | 1.65 (1.34–2.03)* | 0.69 (0.52–0.93)* |