Odds ratios (95% CI) for myocardial infarction associated with temperature and potential confounders in final model—distributed lag effects*
| Potential confounders | Lag (hours) | ||||||
|---|---|---|---|---|---|---|---|
| 1-6 | 7-12 | 13-18 | 19-24 | 25-48 | 49-192 | 193-360 | |
| Temperature (per °C) | 1.019† (1.005 to 1.033) | 1.002 (0.991 to 1.014) | 1.011 (0.997 to 1.026) | 0.989 (0.977 to 1.001) | 0.991 (0.981 to 1.001) | 0.996 (0.986 to 1.006) | 0.991 (0.981 to 1.002) |
| P value | 0.009 | 0.677 | 0.124 | 0.074 | 0.074 | 0.401 | 0.101 |
| Relative humidity (%): | |||||||
| <70 | 1 (reference) | 1 (reference) | 1 (reference) | 1 (reference) | 1 (reference) | 1 (reference) | 1 (reference) |
| 70-79 | 0.97 (0.93 to 1.02) | 1.03 (0.99 to 1.08) | 1.05 (1.00 to 1.09) | 0.95 (0.91 to 1.00) | 1.01 (0.97 to 1.04) | 1.00 (0.96 to 1.04) | 0.98 (0.94 to 1.02) |
| 80-89 | 0.99 (0.94 to 1.04) | 1.06 (1.01 to 1.12) | 1.04 (0.98 to 1.10) | 0.95 (0.90 to 1.00) | 1.00 (0.96 to 1.04) | 1.02 (0.96 to 1.08) | 1.00 (0.95 to 1.06) |
| 90-100 | 0.94 (0.89 to 1.00) | 1.03 (0.96 to 1.11) | 1.06 (0.99 to 1.15) | 0.96 (0.90 to 1.03) | 0.94 (0.88 to 1.02) | 0.94 (0.83 to 1.07) | 1.01 (0.88 to 1.16) |
| P value | 0.186 | 0.089 | 0.209 | 0.107 | 0.329 | 0.517 | 0.592 |
| Nitrogen dioxide (per 10 µg/m3) | 0.997 (0.981 to 1.014) | 1.000 (0.981 to 1.020) | 0.990 (0.970 to 1.010) | 1.016 (0.997 to 1.035) | 0.987 (0.967 to 1.006) | 0.994 (0.963 to 1.025) | 1.009 (0.977 to 1.043) |
| P values | 0.763 | 0.997 | 0.314 | 0.110 | 0.179 | 0.698 | 0.575 |
*All lag terms were included in model simultaneously; model also adjusted for residual seasonality within calendar months by using single harmonic Fourier series.17
†Per °C >20°C.