Appendix Table 3.
Adjusted odds ratio estimates of the association between EHE95/EHE90 and NTDs among selected subgroups, NBDPS, 1997–2007
| Subsets of data | EHE95 | EHE90 |
|---|---|---|
| aOR (95% CI) * | aOR (95% CI) * | |
| No diuretic medication use in the first trimester | 0.90 (0.68, 1.19) | 0.81 (0.61, 1.08) |
| No fever in the first trimester | 0.94 (0.71, 1.25) | 0.75 (0.56, 1.01) |
| Complete residence history | 0.99 (0.74, 1.32) | 0.90 (0.67, 1.21) |
| Live births | 0.92 (0.67, 1.24) | 0.79 (0.58, 1.08) |
| Geographic radius around weather station | ||
| 10 miles | 0.89 (0.61, 1.32) | 0.84 (0.57, 1.24) |
| 20 miles | 0.95 (0.68, 1.31) | 0.79 (0.57, 1.10) |
| 30 miles | 0.92 (0.68, 1.25) | 0.78 (0.57, 1.06) |
| Occupation with potential exposure to elevated environmental temperature | 0.98 (0.71, 1.36) | 0.93 (0.67, 1.28) |
| Spina bifida (overall NBDPS) | 0.97 (0.70, 1.34) | 0.82 (0.59, 1.13) |
| South (AR, TX) | 0.85 (0.46, 1.59) | 0.74 (0.39, 1.38) |
| Southeast (NC, GA) | 0.97 (0.45, 2.08) | 0.65 (0.29, 1.49) |
| Northeast (NY) | 1.32 (0.44, 3.92) | 0.66 (0.19, 2.31) |
| Southwest (UT) | 1.13 (0.47, 2.69) | 1.01 (0.42, 2.45) |
| West (CA) | 0.51 (0.23, 1.16) | 0.53 (0.25, 1.12) |
| Upper Midwest (IA) | 1.35 (0.62, 2.94) | 1.23 (0.56, 2.72) |
| Anencephaly (overall NBDPS) | 1.00 (0.62, 1.62) | 0.86 (0.53, 1.40) |
| South (AR, TX) | 0.68 (0.22, 2.06) | 0.35 (0.10, 1.24) |
| Southeast (NC, GA) | 1.88 (0.75, 4.67) | 0.82 (0.29, 2.29) |
| Northeast (NY) | 6.64 (0.67, 19.88) | 3.64 (0.67, 19.85) |
| Southwest (UT) | 0.53 (0.10, 2.91) | 1.65 (0.33, 8.17) |
| West (CA) | 0.93 (0.39, 2.22) | 0.86 (0.37, 1.98) |
| Upper Midwest (IA) | 0.80 (0.27, 2.35) | 1.26 (0.44, 3.58) |
Adjusted for maternal age, maternal race/ethnicity and maternal body mass index (BMI)
EHE95 = extreme heat event defined as at least two consecutive days with daily universal apparent maximum temperature above the 95th percentile of the universal apparent maximum temperature distribution for the summer season and for climate region; EHE90 = extreme heat event defined as at least three consecutive days with daily universal apparent maximum temperature above the 90th percentile of the universal apparent maximum temperature distribution for the summer season and for climate region; NTDs = neural tube defects; NBDPS = National Birth Defects Prevention Study; aOR = adjusted odds ratio; CI = confidence interval; AR = Arkansas; TX = Texas; NC = North Carolina; GA = Georgia; NY = New York; UT = Utah; CA = California; IA = Iowa