Table 2.
Estimated effects of temperature and potential confounders in final model
| Potential confounders | Relative risk (95% CI) | P value |
|---|---|---|
| Temperature (per °C drop): | ||
| Lag 0-1 | 1.002 (0.998 to 1.005) | <0.001 |
| Lag 2-7 | 1.006 (1.002 to 1.011) | |
| Lag 8-14 | 1.007 (1.003 to 1.011) | |
| Lag 15-21 | 1.003 (0.999 to 1.007) | |
| Lag 22-28 | 1.002 (0.998 to 1.006) | |
| Cumulative effect over all lags | 1.020 (1.011 to 1.029) | |
| Relative humidity (%): | ||
| 55 | 1.03 (0.99 to 1.06) | 0.29 |
| 65 | 1.01 (0.99 to 1.03) | |
| 75 | 1.00 (reference) | |
| 85 | 1.01 (0.98 to 1.04) | |
| 95 | 1.06 (0.99 to 1.13) | |
| Day of week: | ||
| Sunday | 1.00 (reference) | <0.001 |
| Monday | 1.14 (1.11 to 1.17) | |
| Tuesday | 1.05 (1.02 to 1.08) | |
| Wednesday | 1.07 (1.04 to 1.10) | |
| Thursday | 1.04 (1.01 to 1.07) | |
| Friday | 1.08 (1.05 to 1.11) | |
| Saturday | 0.99 (0.96 to 1.02) | |
| Public holiday: | ||
| No | 1.00 (reference) | 0.21 |
| Yes | 0.97 (0.92 to 1.02) | |
| Confirmed cases of influenza A*: | ||
| 0 | 1.00 (reference) | 0.58 |
| 1 | 1.02 (0.99 to 1.05) | |
| ≥2 | 1.01 (0.97 to 1.05) | |
| Confirmed cases of respiratory syncytial virus*: | ||
| 0 | 1.00 (reference) | 0.84 |
| 1 | 0.99 (0.96 to 1.02) | |
| ≥2 | 1.01 (0.95 to 1.06) | |
| PM10 (per μg/m3)†: | ||
| Lag 0 | 1.001 (1.000 to 1.002) | 0.02 |
| Lag 1 | 0.999 (0.998 to 1.000) | |
| Lag 2 | 0.999 (0.998 to 1.000) | |
| Lag 3 | 1.000 (0.999 to 1.001) | |
| Ozone (per μg/m3) | ||
| Lag 0 | 1.000 (0.999 to 1.001) | 0.19 |
| Lag 1 | 0.999 (0.999 to 1.000) | |
| Lag 2 | 1.000 (0.999 to 1.001) | |
| Lag 3 | 1.000 (0.999 to 1.000) |
Model adjusted for season and trend using spline function of calendar date, with 7 knots per calendar year.
*Laboratory confirmed cases.
†Particulate matter with diameters less than 10 μm.