Table 2.
Prevalence proportion ratios and 95% confidence intervals for the relationship between natural gas well activity within a 2-mile buffer of the birth residence and specific congenital anomalies (N=476,600).
| IDW Summed Well Count by Anomaly Type | N with Anomalies | Adjusteda PPR (95% CI) |
|---|---|---|
| Critical Congenital Heart Defects | 874 | |
| 0 | 494 | Reference |
| 0.25–1.88 | 132 | 1.02 (0.84, 1.24) |
| >1.88–9.00 | 128 | 1.01 (0.83, 1.23) |
| >9.00–47679.13 | 120 | 0.91 (0.75, 1.11) |
| Neural Tube Defects | 217 | |
| 0 | 114 | Reference |
| 0.25–1.88 | 28 | 0.89 (0.58, 1.37) |
| >1.88–9.00 | 39 | 1.34 (0.93, 1.93) |
| Oral Clefts | 603 | |
| 0 | 340 | Reference |
| 0.25–1.88 | 75 | 0.85 (0.67, 1.10) |
| >1.88–9.00 | 94 | 1.06 (0.84, 1.34) |
| >9.00–47679.13 | 94 | 1.03 (0.82, 1.29) |
IDW: Inverse Distance Weight, PPR: Prevalence proportion ratio, 95% CI: 95% confidence interval
a
Adjusted for maternal education