Table 4.
RRs (95% CI) of stroke hospitalisations for every 10 µg/m3 increase in ambient PM2.5, NO2 and O3 in the single-pollutant model, across lag 0–3 days
| Subgroups | RR (95% CI) | ||
| PM2.5 | NO2 | O3 | |
| All strokes | 1.029 (1.013 to 1.045) |
1.054 (1.031 to 1.077) |
1.012 (1.002 to 1.022) |
| Sex | |||
| Male | 1.029 (1.011 to 1.046) |
1.056 (1.032 to 1.080) |
1.011 (0.999 to 1.022) |
| Female | 1.030 (1.009 to 1.052) |
1.050 (1.020 to 1.080) |
1.013 (1.000 to 1.027) |
| Age | |||
| <40 | 1.030 (0.990 to 1.070) |
1.084 (1.027 to 1.145) |
0.998 (0.974 to 1.023) |
| 40–64 | 1.025 (1.008 to 1.044) |
1.058 (1.033 to 1.084) |
1.013 (1.002 to 1.024) |
| >65 | 1.033 (1.012 to 1.055) |
1.046 (1.017 to 1.076) |
1.012 (0.999 to 1.025) |
| Education | |||
| Primary and below | 1.013 (0.991 to 1.036) |
1.050 (1.019 to 1.081) |
1.007 (0.993 to 1.021) |
| Junior high school | 1.043 (1.021 to 1.065) |
1.072 (1.041 to 1.104) |
1.023 (1.009 to 1.037) |
| Senior high school and above | 1.028 (1.006 to 1.049) |
1.036 (1.007 to 1.066) |
1.003 (0.990 to 1.016) |
| Stroke subtype | |||
| Intracerebral haemorrhage | 1.021 (0.995 to 1.048) |
1.058 (1.021 to 1.096) |
1.008 (0.991 to 1.025) |
| Cerebral infarction | 1.029 (1.011 to 1.047) |
1.050 (1.026 to 1.075) |
1.012 (1.001 to 1.023) |
| Season | |||
| Spring | 1.031 (0.989 to 1.076) |
1.034 (0.989 to 1.081) |
1.012 (0.989 to 1.035) |
| Summer | 1.031 (0.989 to 1.075) |
0.992 (0.944 to 1.044) |
1.015 (0.990 to 1.041) |
| Autumn | 1.021 (0.993 to 1.050) |
1.040 (0.994 to 1.089) |
1.009 (0.992 to 1.025) |
| Winter | 1.073 (1.022 to 1.126) |
1.095 (1.024 to 1.170) |
1.033 (0.983 to 1.086) |
NO2, nitrogen dioxide; O3, ozone; PM2.5, fine particulate matter; RR, relative risk.