Table 1.
Distribution of births to non-Hispanic black mothers across exposure and covariate levels: New York City birth records, 1995-2003
| Continuous variables | Mean (SD) | Median (10th, 90th percentile) |
|
|---|---|---|---|
| Hispanic densitya (%) | 26.0 (21.3) | 18.7 (5.2, 61.9) | |
| Asian densitya (%) | 3.3 (5.9) | 1.2 (0.3, 8.1) | |
| White densitya (%) | 8.8 (15.0) | 2.2 (0.6, 23.6) | |
| Black densitya (%) | 58.1 (27.2) | 64.1 (17.9, 88.9) | |
|
| |||
| Categorical variables | N | % | % PTB |
|
| |||
| Age (years) | |||
| <20 | 27,714 | 10.8% | 10.8% |
| 20-34 | 183,203 | 71.4% | 10.2% |
| 35+ | 45,756 | 17.8% | 13.5% |
| Maternal education (years) | |||
| <12, age<20 | 18,130 | 7.2% | 11.1% |
| <12, age>=20 | 46,091 | 18.2% | 12.0% |
| 12 | 93,299 | 36.9% | 11.0% |
| 13-15 | 63,635 | 25.2% | 10.1% |
| 16+ | 31,678 | 12.5% | 9.5% |
| Previous births | |||
| 1 | 107,920 | 42.1% | 10.5% |
| 2-5 | 144,273 | 56.2% | 10.9% |
| 6+ | 4,469 | 1.7% | 17.3% |
| Prepregnancy weight (pounds)b | |||
| <125 | 44,777 | 19.0% | 12.0% |
| 125-150 | 86,615 | 36.7% | 10.3% |
| >150 | 104,617 | 44.3% | 10.0% |
| Tobacco use | |||
| Nonsmoker | 240,397 | 94.2% | 10.3% |
| Smoker | 14,690 | 5.8% | 18.6% |
| Late or no prenatal care a | |||
| No | 169,652 | 75.0% | 10.1% |
| Yes | 56,563 | 25.0% | 11.0% |
| Payment for delivery | |||
| Private insurance | 86,774 | 34.6% | 9.9% |
| Medicaid | 155,211 | 61.8% | 11.0% |
| self pay | 9,095 | 3.6% | 15.9% |
| Nativity | |||
| us-born | 141,969 | 55.7% | 11.9% |
| Foreign-born | 112,966 | 44.3% | 9.5% |
| Residential stability | |||
| Less stable | 102,521 | 39.9% | 10.4% |
| More stable | 154,139 | 60.1% | 11.1% |
| Neighborhood deprivation | |||
| Richer | 93,087 | 36.3% | 10.0% |
| Poorer | 163,559 | 63.7% | 11.3% |
a
Individuals reporting more than one race or ‘other’ race not included
b
Variables were missing for less than 4% of observations, with the exception of prepregnancy weight (8.1% missing) and prenatal care (11.9% missing)