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

SubgroupsRR (95% CI)
PM2.5NO2O3
All strokes1.029
(1.013 to 1.045)
1.054
(1.031 to 1.077)
1.012
(1.002 to 1.022)
Sex
 Male1.029
(1.011 to 1.046)
1.056
(1.032 to 1.080)
1.011
(0.999 to 1.022)
 Female1.030
(1.009 to 1.052)
1.050
(1.020 to 1.080)
1.013
(1.000 to 1.027)
Age
 <401.030
(0.990 to 1.070)
1.084
(1.027 to 1.145)
0.998
(0.974 to 1.023)
 40–641.025
(1.008 to 1.044)
1.058
(1.033 to 1.084)
1.013
(1.002 to 1.024)
 >651.033
(1.012 to 1.055)
1.046
(1.017 to 1.076)
1.012
(0.999 to 1.025)
Education
 Primary and below1.013
(0.991 to 1.036)
1.050
(1.019 to 1.081)
1.007
(0.993 to 1.021)
 Junior high school1.043
(1.021 to 1.065)
1.072
(1.041 to 1.104)
1.023
(1.009 to 1.037)
 Senior high school and above1.028
(1.006 to 1.049)
1.036
(1.007 to 1.066)
1.003
(0.990 to 1.016)
Stroke subtype
 Intracerebral haemorrhage1.021
(0.995 to 1.048)
1.058
(1.021 to 1.096)
1.008
(0.991 to 1.025)
 Cerebral infarction1.029
(1.011 to 1.047)
1.050
(1.026 to 1.075)
1.012
(1.001 to 1.023)
Season
 Spring1.031
(0.989 to 1.076)
1.034
(0.989 to 1.081)
1.012
(0.989 to 1.035)
 Summer1.031
(0.989 to 1.075)
0.992
(0.944 to 1.044)
1.015
(0.990 to 1.041)
 Autumn1.021
(0.993 to 1.050)
1.040
(0.994 to 1.089)
1.009
(0.992 to 1.025)
 Winter1.073
(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.