Table 4.
Odds ratios for ventricular arrhythmias associated with a 1 °C decrease in outdoor temperature (96 h average), 1 °C decrease in estimated indoor temperature (24 h average), and 0.5 g/m3 decrease in outdoor absolute humidity (96 h average) among 84 patients (N = up to 787 arrhythmias), Boston Implantable Cardioverter Defibrillator Study, 1995–2002.
| Parameters included in model | ORa | 95% CI | P-value |
|---|---|---|---|
| Outdoor temperatureb | |||
| ≤4.5 °C | 1.00 | (0.96–1.05) | 0.90 |
| >4.5 °C | 1.08 | (1.02–1.14) | 0.01 |
| + PM2.5 | |||
| ≤ 4.5 °C | 1.00 | (0.96–1.05) | 0.90 |
| >4.5 °C | 1.08 | (1.02–1.14) | 0.01 |
| + Ozone | |||
| ≤4.5 °C | 1.00 | (0.96–1.04) | 0.98 |
| >4.5 °C | 1.09 | (1.03–1.16) | 0.004 |
| + PM2.5 + ozone | |||
| ≤4.5 °C | 1.00 | (0.96–1.04) | 0.999 |
| >4.5 °C | 1.09 | (1.03–1.16) | 0.004 |
| Estimated indoor temperature | 1.08 | (1.01–1.17) | 0.03 |
| + PM2.5 | 1.12 | (1.03–1.21) | 0.01 |
| + Ozone | 1.12 | (1.03–1.22) | 0.006 |
| + PM2.5 + ozone | 1.16 | (1.05–1.27) | 0.003 |
| Absolute humidity | 1.06 | (1.03–1.08) | 4.0 × 10−6 |
| + PM2.5 | 1.06 | (1.03–1.08) | 2.3 × 10−6 |
| + Ozone | 1.06 | (1.03–1.08) | 3.2 × 10−6 |
| + PM2.5 + ozone | 1.06 | (1.03–1.08) | 2.3 × 10−6 |
Abbreviations: CI, confidence interval; OR, odds ratio.
a
Matched on month, day of the week, and hour.
b
The cutpoint for outdoor temperature was chosen based on model-specific goodness-of-fit tests.