Table 7.
Adjusted odds ratios* for emergency department visits for asthma among patients 45 – 64 years of age, by season
| Pollutant | Mean | IQR | All seasons | Season | ||||
| October to March | April to September | |||||||
| OR | 95% C.I. | OR | 95% C.I. | OR | 95% C.I. | |||
| SO2 | Same day | 3.0 | 0.97 | 0.92–1.01 | 0.96 | 0.91–1.02 | 0.96 | 0.90–1.04 |
| 1-day lag | 0.99 | 0.95–1.04 | 0.99 | 0.94–1.05 | 0.99 | 0.93–1.07 | ||
| 3-day average | 0.95 | 0.89–1.02 | 0.94 | 0.87–1.02 | 0.98 | 0.88–1.09 | ||
| 5-day average | 0.96 | 0.89–1.04 | 0.96 | 0.87–1.05 | 0.98 | 0.86–1.12 | ||
| NO2 | Same day | 13.5 | 0.97 | 0.92–1.01 | 0.99 | 0.94–1.04 | 0.89 | 0.81–0.98 |
| 1-day lag | 0.98 | 0.93–1.02 | 0.97 | 0.92–1.03 | 0.98 | 0.89–1.08 | ||
| 3-day average | 0.95 | 0.89–1.00 | 0.95 | 0.89–1.02 | 0.93 | 0.82–1.04 | ||
| 5-day average | 0.96 | 0.89–1.02 | 0.95 | 0.88–1.03 | 0.99 | 0.86–1.14 | ||
| CO | Same day | 0.5 | 1.00 | 0.97–1.03 | 1.01 | 0.97–1.05 | 0.93 | 0.84–1.03 |
| 1-day lag | 0.99 | 0.96–1.03 | 0.99 | 0.95–1.03 | 1.04 | 0.94–1.15 | ||
| 3-day average | 0.98 | 0.94–1.03 | 0.99 | 0.94–1.04 | 0.96 | 0.84–1.11 | ||
| 5-day average | 0.98 | 0.93–1.03 | 0.99 | 0.93–1.04 | 1.00 | 0.84–1.18 | ||
| O3 (Max) | Same day | 18.0 | 1.00 | 0.94–1.06 | 0.97 | 0.89–1.06 | 1.01 | 0.92–1.10 |
| 1-day lag | 1.05 | 1.00–1.11 | 1.04 | 0.96–1.13 | 1.04 | 0.97–1.13 | ||
| 3-day average | 1.08 | 1.00–1.16 | 1.06 | 0.94–1.18 | 1.07 | 0.97–1.19 | ||
| 5-day average | 1.12 | 1.03–1.22 | 1.09 | 0.96–1.24 | 1.12 | 1.00–1.26 | ||
| PM2.5‡ | Same day | 6.3 | 1.04 | 1.00–1.08 | 0.96 | 0.90–1.03 | 1.08 | 1.03–1.14 |
| 1-day lag | 1.04 | 1.00–1.08 | 1.00 | 0.93–1.07 | 1.06 | 1.01–1.11 | ||
| 3-day average | 1.06 | 1.01–1.12 | 0.97 | 0.89–1.07 | 1.12 | 1.05–1.20 | ||
| 5-day average | 1.07 | 1.01–1.14 | 0.98 | 0.88–1.09 | 1.14 | 1.05–1.23 | ||
| PM10‡ | Same day | 16.0 | 1.04 | 0.99–1.09 | 1.00 | 0.93–1.07 | 1.08 | 1.02–1.15 |
| 1-day lag | 1.05 | 1.01–1.10 | 1.02 | 0.95–1.10 | 1.07 | 1.01–1.14 | ||
| 3-day average | 1.06 | 1.00–1.12 | 0.99 | 0.91–1.08 | 1.12 | 1.04–1.22 | ||
| 5-day average | 1.06 | 0.99–1.13 | 0.99 | 0.90–1.10 | 1.13 | 1.03–1.23 | ||
*Odds ratios were calculated in relation to an increase in the interquartile range (IQR) of selected air pollutants and were adjusted for relative humidity and temperature, and daily number of visits for influenza (all ages combined).
‡ Particulate data were only available between January 1, 1998 and December 31, 2002