TABLE 4.
Analysis for a secondary outcome: child’s birth weight in CPP study
| Variables | SRS | IPW | AIPW | |
|---|---|---|---|---|
| Int | Estimate | 3208.14 | 3209.44 | 3089.24 |
| SE | 86.54 | 79.49 | 21.97 | |
| 95% CI | (3038.52, 3377.76) | (3053.64, 3365.24) | (3046.18, 3132.30) | |
| PCB | Estimate | −0.67 | −5.44 | −5.49 |
| SE | 9.20 | 8.41 | 8.46 | |
| 95% CI | (−18.70, 17.36) | (−21.92, 11.04) | (−22.07, 11.09) | |
| EDU | Estimate | −8.97 | −8.81 | 1.70 |
| SE | 9.10 | 8.39 | 1.36 | |
| 95% CI | (−26.81, 8.87) | (−25.25, 7.63) | (−0.97, 4.37) | |
| SES | Estimate | 13.94 | 16.06 | 13.58 |
| SE | 10.77 | 10.33 | 2.16 | |
| 95% CI | (−7.17, 35.05) | (−4.19, 36.31) | (9.35, 17.81) | |
| RACE | Estimate | 204.10 | 206.16 | 189.84 |
| (WHITE = 1) | SE | 38.13 | 37.93 | 6.29 |
| 95% CI | (129.37, 278.83) | (131.82, 280.50) | (177.51, 202.17) | |
| GENDER | Estimate | −147.69 | −145.65 | −119.25 |
| (FEMALE = 1) | SE | 34.72 | 31.96 | 5.33 |
| 95% CI | (−215.74, −79.64) | (−208.29, −83.01) | (−129.70, −108.80) |
The response variable is child’s birth weight in grams. The expensive exposure is mother’s polychlorinated biphenyl (PCB) level. Other confounding variables include: parent’s education level (EDU), social economic status of the child’s family (SES), race ethnicity of the child (RACE), and gender of the child (GENDER). The results under simple random sample (SRS) are the regression analysis using the SRS portion of the outcome-dependent sampling sample. Inverse probability weighted (IPW) is the inverse probability weighted estimating equation, and augmented IPW (AIPW) is the augmented inverse probability weighted estimating equation we proposed. SE, standard error.