Table 7.
Percent change (95% CI) in stroke admissions associated with a 10.0 μg/m3 increase in NO2, SO2, and ozone, and 1.0 mg/m3 increase in CO in sensitivity analyses.
| Variables | Sensitivity Analysis I * | Sensitivity Analysis II # | Sensitivity Analysis III † |
|---|---|---|---|
| NO2 | |||
| Lag0 | 0.77 (0.45 to 1.09) | 0.82 (0.52 to 1.13) | 1.14 (0.87 to 1.40) |
| Lag1 | 0.38 (0.10 to 0.66) | 0.39 (0.11 to 0.67) | 0.75 (0.49 to 1.02) |
| Lag2 | −0.17 (−0.44 to 0.10) | −0.14 (−0.41 to 0.12) | 0.08 (−0.19 to 0.34) |
| 3 days average | 0.42 (0.02 to 0.83) | 0.20 (−0.20 to 0.60) | 0.91 (0.56 to 1.27) |
| SO2 | |||
| Lag0 | 0.38 (0.07 to 0.69) | 0.72 (0.43 to 1.02) | 1.11 (0.83 to 1.39) |
| Lag1 | 0.20 (−0.09 to 0.50) | 0.40 (0.11 to 0.68) | 0.76 (0.49 to 1.04) |
| Lag2 | −0.18 (−0.45 to 0.09) | 0.16 (−0.10 to 0.42) | 0.35 (0.08 to 0.61) |
| 3 days average | −0.02 (−0.46 to 0.43) | 0.36 (−0.06 to 0.78) | 1.11 (0.70 to 1.51) |
| CO | |||
| Lag0 | 1.19 (0.42 to 1.98) | 1.32 (0.56 to 2.10) | 2.36 (1.68 to 3.04) |
| Lag1 | 0.41 (−0.28 to 1.10) | 0.35 (−0.33 to 1.03) | 1.33 (0.65 to 2.01) |
| Lag2 | −0.25 (−0.90 to 0.40) | −0.43 (−1.07 to 0.22) | −0.09 (−0.75 to 0.58) |
| 3 days average | 0.43 (−0.55 to 1.43) | −0.13 (−1.10 to 0.84) | 2.01 (1.07 to 2.95) |
| Ozone | |||
| Lag0 | 0.29 (0.14 to 0.44) | 0.24 (0.09 to 0.38) | 0.23 (0.10 to 0.36) |
| Lag1 | 0.16 (0.02 to 0.30) | 0.23 (0.09 to 0.37) | 0.24 (0.11 to 0.37) |
| Lag2 | −0.07 (−0.21 to 0.07) | 0.03 (−0.10 to 0.17) | 0.07 (−0.06 to 0.20) |
| 3 days average | 0.28 (0.08 to 0.49) | 0.22 (0.02 to 0.42) | 0.12 (−0.06 to 0.31) |
CI, confidence interval; NO2, nitrogen dioxide; SO2, sulfur dioxide; CO, carbon monoxide. * Using time-stratified case-crossover design. # Changing the temperature and relative humidity degrees of freedom to four instead of three. † Adjusting temperature and relative humidity lagged by up to two weeks.