TABLE 2—
Odds Ratios for Preterm Birth by Cross-Sectional Neighborhood Poverty Categories and Individual-Level Covariates: Maternal and Infant Health Assessment, California, 2005–2009
| Variable | Crude,a OR (95% CI) | Demographic, OR (95% CI) | Full, OR (95% CI) |
| Cross-sectional neighborhood poverty | |||
| High poverty | 1.29 (1.12, 1.50) | 1.18 (1.00, 1.38) | 1.08 (0.91, 1.28) |
| Moderate poverty | 1.16 (1.01, 1.32) | 1.12 (0.97, 1.29) | 1.06 (0.91, 1.22) |
| Low poverty (Ref) | 1.00 | 1.00 | 1.00 |
| Age | 1 (0.99, 1.01) | 1.01 (1.00, 1.02) | 1.01 (1.00, 1.02) |
| Parity | |||
| First birth (Ref) | 1.00 | 1.00 | |
| 2–4 births | 1.01 (0.92, 1.11) | 1.02 (0.92, 1.13) | 0.96 (0.86, 1.08) |
| ≥ 5 births | 1.44 (1.17, 1.78) | 1.38 (1.09, 1.75) | 1.13 (0.87, 1.48) |
| Marital status | |||
| Unmarried | 1.27 (1.15, 1.39) | 1.19 (1.07, 1.33) | 1.10 (0.97, 1.24) |
| Married (Ref) | 1.00 | 1.00 | 1.00 |
| Race/ethnicity | |||
| Asian/Pacific Islander | 1.06 (0.89, 1.27) | 1.08 (0.90, 1.29) | 1.12 (0.93, 1.35) |
| Non-Hispanic Black | 1.72 (1.49, 1.99) | 1.53 (1.31, 1.79) | 1.45 (1.23, 1.71) |
| Hispanic, immigrant | 1.13 (1.00, 1.28) | 1.04 (0.91, 1.19) | 0.84 (0.70, 1.01) |
| Hispanic, US-born | 1.31 (1.14, 1.50) | 1.21 (1.05, 1.41) | 1.09 (0.92, 1.28) |
| Non-Hispanic White (Ref) | 1.00 | 1.00 | 1.00 |
| Maternal education | |||
| < high school | 1.56 (1.36, 1.79) | 1.52 (1.24, 1.88) | |
| High school or GED | 1.37 (1.20, 1.57) | 1.31 (1.08, 1.58) | |
| Some college | 1.33 (1.16, 1.52) | 1.19 (1.01, 1.40) | |
| College graduate (Ref) | 1.00 | 1.00 | |
| Mother’s parents’ education | |||
| < high school | 1.20 (1.05, 1.36) | 0.97 (0.81, 1.16) | |
| High school or GED | 1.08 (0.93, 1.25) | 0.90 (0.76, 1.06) | |
| Some college | 1.09 (0.93, 1.27) | 0.96 (0.81, 1.13) | |
| College graduate (Ref) | 1.00 | 1.00 | |
| Income, % of FPL | |||
| Missing | 1.49 (1.24, 1.79) | 1.29 (1.03, 1.62) | |
| 0–100 | 1.53 (1.33, 1.75) | 1.30 (1.07, 1.58) | |
| 101–200 | 1.42 (1.22, 1.66) | 1.24 (1.02, 1.51) | |
| 201–300 | 1.29 (1.06, 1.57) | 1.15 (0.92, 1.42) | |
| 301–400 | 1.29 (1.04, 1.61) | 1.17 (0.93, 1.48) | |
| ≥ 401 (Ref) | 1.00 | 1.00 |
Note. CI = confidence interval; FPL = federal poverty level (according to US Census); GED = general equivalency diploma; OR = odds ratio. Models exclude 12 records that were missing data on preterm births. The sample size was n = 23 279.
a
Crude associations between individual covariates and preterm birth from bivariate logistic models including only those covariates.