Table 4.
Associations between ambient heat and stillbirth in different periods in OneFlorida, 2012-2017 (n=1,876).
| Adjusted OR (95% CI) | ||||||
|---|---|---|---|---|---|---|
| Unstratified | Stratified by NDI | Stratified by Race/ethnicity | ||||
| NDI (Quartile 4) | NDI (Quartiles 1-3) | Non-Hispanic White | Non-Hispanic Black | Hispanics | ||
| Stillbirths in June to September | ||||||
| n | 646 | 154 | 492 | 223 | 241 | 125 |
| Average Heat Index (Lag 1-7 day) | ||||||
| Continuous | ||||||
| Each 1°F increase | 1.03 (1.00, 1.06) | 1.09 (1.03, 1.16) | 1.01 (0.98, 1.04) | 1.02 (0.97, 1.07) | 1.04 (1.00, 1.09) | 1.04 (0.97, 1.12) |
| Each 1°C increase | 1.05 (1.00, 1.10) | 1.17 (1.05, 1.31) | 1.02 (0.96, 1.08) | 1.03 (0.95, 1.12) | 1.08 (1.00, 1.17) | 1.08 (0.95, 1.22) |
| Quartiles | ||||||
| Quartile 1 (≤82.7°F / 28.2°C) | Reference | Reference | Reference | Reference | Reference | Reference |
| Quartile 2 (82.7-86.9°F / 28.2-30.5°C) | 1.2 (0.9, 1.6) | 0.8 (0.4, 1.5) | 1.4 (0.9, 1.9) | 1.0 (0.6, 1.6) | 1.4 (0.9, 2.3) | 1.7 (0.9, 3.4) |
| Quartile 3 (86.9-89.8°F / 30.5-32.1°C) | 1.1 (0.8, 1.5) | 1.9 (1.0, 3.9) | 0.9 (0.7, 1.4) | 1.0 (0.6, 1.7) | 1.1 (0.6, 1.8) | 1.3 (0.6, 2.7) |
| Quartile 4 (>89.8°F / 32.1°C) | 1.5 (1.0, 2.1) | 2.4 (1.2, 5.2) | 1.3 (0.8, 1.9) | 1.4 (0.8, 2.6) | 1.8 (1.0, 3.2) | 1.5 (0.7, 3.3) |
| 90th Percentile | ||||||
| ≤90th Percentile (≤91.5°F / 33.1°C) | Reference | Reference | Reference | Reference | Reference | Reference |
| >90th Percentile (>91.5°F / 33.1°C) | 1.2 (0.8, 1.6) | 2.0 (1.0, 3.9) | 1.0 (0.7, 1.4) | 0.9 (0.5, 1.7) | 1.2 (0.8, 2.0) | 1.2 (0.6, 2.4) |
| Maximum Heat Index Risk Level (Lag 1-7 day) | ||||||
| No warning | Reference | Reference | Reference | Reference | Reference | Reference |
| Caution | 1.6 (1.0, 2.7) | 1.2 (0.4, 3.2) | 1.8 (1.0, 3.2) | 1.1 (0.5, 2.2) | 3.6 (1.2, 10.6) | 1.7 (0.3, 8.3) |
| ≥Extreme caution | 1.6 (0.9, 2.7) | 1.6 (0.5, 4.6) | 1.6 (0.9, 2.9) | 1.2 (0.6, 2.6) | 3.4 (1.1, 10.7) | 1.3 (0.2, 7.1) |
| Stillbirths in April, May, and October | ||||||
| n | 473 | 117 | 356 | 162 | 179 | 88 |
| Average Heat Index (Lag 1-7 day) | ||||||
| Continuous | ||||||
| Each 1°F increase | 1.03 (1.00, 1.05) | 1.02 (0.96, 1.08) | 1.03 (1.00, 1.06) | 1.04 (1.00, 1.09) | 1.03 (0.98, 1.07) | 1.00 (0.94, 1.07) |
| Each 1°C increase | 1.05 (1.00, 1.10) | 1.03 (0.94, 1.14) | 1.05 (1.00, 1.11) | 1.08 (1.00, 1.17) | 1.05 (0.97, 1.13) | 1.00 (0.90, 1.12) |
| Quartiles | ||||||
| Quartile 1 (≤71.3°F / 21.8°C) | Reference | Reference | Reference | Reference | Reference | Reference |
| Quartile 2 (71.3-74.8°F / 21.8-23.8°C) | 2.1 (1.5, 2.9) | 2.1 (1.1, 4.2) | 2.0 (1.4, 3.0) | 2.3 (1.3, 4.1) | 1.7 (1.0, 2.8) | 2.1 (0.9, 4.8) |
| Quartile 3 (74.8-78.8°F / 23.8-26.0°C) | 1.8 (1.3, 2.7) | 1.2 (0.6, 2.3) | 2.1 (1.4, 3.2) | 1.9 (1.0, 3.6) | 2.0 (1.1, 3.6) | 1.5 (0.6, 3.8) |
| Quartile 4 (>78.8°F / 26.0°C) | 1.6 (1.1, 2.5) | 1.1 (0.5, 2.8) | 1.8 (1.1, 3.0) | 1.7 (0.8, 3.5) | 1.6 (0.8, 3.2) | 1.5 (0.6, 4.1) |
| 90th Percentile | ||||||
| ≤90th Percentile (≤82.0°F / 27.8°C) | Reference | Reference | Reference | Reference | Reference | Reference |
| >90th Percentile (>82.0°F / 27.8°C) | 0.6 (0.4, 1.0) | 0.7 (0.3, 1.5) | 0.6 (0.4, 1.1) | 0.5 (0.2, 1.2) | 0.8 (0.4, 1.7) | 0.4 (0.2, 1.1) |
| Maximum Heat Index Risk Level (Lag 1-7 day) | ||||||
| No warning | Reference | Reference | Reference | Reference | Reference | Reference |
| Caution | 1.2 (0.9, 1.6) | 0.8 (0.5, 1.5) | 1.4 (1.0, 1.9) | 1.4 (0.9, 2.2) | 1.0 (0.6, 1.6) | 1.3 (0.7, 2.4) |
| ≥Extreme caution | 0.9 (0.5, 1.7) | 0.4 (0.1, 1.8) | 1.2 (0.6, 2.4) | 0.5 (0.1, 1.8) | 0.9 (0.3, 2.4) | 1.5 (0.4, 5.7) |
| Stillbirths in November to March | ||||||
| n | 757 | 185 | 572 | 229 | 312 | 155 |
| Average Heat Index (Lag 1-7 day) | ||||||
| Continuous | ||||||
| Each 1°F increase | 0.99 (0.97, 1.01) | 0.99 (0.96, 1.02) | 0.99 (0.97, 1.01) | 0.98 (0.95, 1.01) | 0.99 (0.97, 1.02) | 1.00 (0.96, 1.04) |
| Each 1°C increase | 0.98 (0.95, 1.01) | 0.98 (0.92, 1.04) | 0.98 (0.94, 1.01) | 0.96 (0.91, 1.02) | 0.99 (0.94, 1.03) | 1.00 (0.93, 1.07) |
| Quartiles | ||||||
| Quartile 1 (≤58.2°F / 14.6°C) | Reference | Reference | Reference | Reference | Reference | Reference |
| Quartile 2 (58.2-63.9°F / 14.6-17.7°C) | 1.0 (0.8, 1.2) | 1.1 (0.6, 1.8) | 0.9 (0.7, 1.3) | 0.8 (0.5, 1.3) | 1.0 (0.7, 1.5) | 1.4 (0.8, 2.6) |
| Quartile 3 (63.9-68.7°F / 17.7-20.5°C) | 0.8 (0.6, 1.1) | 1.1 (0.6, 1.9) | 0.8 (0.6, 1.1) | 0.7 (0.4, 1.3) | 0.8 (0.5, 1.3) | 1.2 (0.6, 2.4) |
| Quartile 4 (>68.7°F / 20.5°C) | 0.7 (0.5, 1.0) | 0.7 (0.4, 1.4) | 0.7 (0.5, 1.1) | 0.6 (0.3, 1.1) | 0.8 (0.5, 1.3) | 1.4 (0.6, 2.9) |
| 90th Percentile | ||||||
| ≤90th Percentile (≤72.1°F / 22.3°C) | Reference | Reference | Reference | Reference | Reference | Reference |
| >90th Percentile (>72.1°F / 22.3°C) | 1.0 (0.7, 1.4) | 0.7 (0.3, 1.5) | 1.1 (0.8, 1.6) | 0.8 (0.4, 1.6) | 1.1 (0.6, 1.8) | 1.0 (0.5, 2.0) |
| Maximum Heat Index Risk Level (Lag 1-7 day) | ||||||
| No warning | Reference | Reference | Reference | Reference | Reference | Reference |
| Caution | 0.5 (0.3, 0.9) | 0.5 (0.1, 2.5) | 0.5 (0.2, 1.0) | 0.3 (0.1, 1.5) | 0.6 (0.2, 1.3) | 0.2 (0.1, 1.4) |
| ≥Extreme caution | - | - | - | - | - | - |
a
Adjusted for PM2.5 and O3.