Table 5.
The Longitudinal analyses of methemoglobin and predictor variables (n = 327)
| Parameter | β estimate | SE | 95% CI | p-value |
|---|---|---|---|---|
| Intercept | -0.841 | 0.595 | -2.007, 0.324 | 0.157 |
| Gestational age (weeks) | -0.043 | 0.005 | -0.054, -0.033 | <0.0001 |
| Carboxyhemoglobin | 0.121 | 0.043 | 0.037, 0.205 | 0.005 |
| Vegetable 24 hrs (yes) | -0.165 | 0.127 | -0.414, 0.084 | 0.194 |
| Cured meats (yes) | 0.009 | 0.104 | -0.196, 0.213 | 0.934 |
| Water intake (cups/day) | -0.011 | 0.013 | -0.037, 0.015 | 0.409 |
| Drinking water (bottled) | -0.211 | 0.157 | -0.519, 0.098 | 0.181 |
| Water source (private well) | -0.099 | 0.134 | -0.362, 0.162 | 0.455 |
| Season methemoglobin tested (fall vs. winter) | 0.388 | 0.143 | 0.107, 0.668 | 0.007 |
| Season methemoglobin tested (spring vs. winter) | -0.146 | 0.153 | -0.445, 0.154 | 0.340 |
| Season methemoglobin tested (summer vs. winter) | 0.039 | 0.154 | -0.262, 0.342 | 0.796 |
| Water treatment (none vs. nitrate removal) | 0.029 | 0.205 | -0.372, 0.430 | 0.887 |
| Water treatment (other vs. nitrate removal) | 0.321 | 0.185 | -0.042, 0.684 | 0.082 |
| Vitamin use (no) | -0.140 | 0.163 | -0.459, 0.177 | 0.387 |
| Nitrosatable drugs (no) | 0.149 | 0.125 | -0.096, 0.394 | 0.234 |