Table 4

Odds of a 20% decrement in PEFR below the median by lag in all schools combined for all children and for wheezy children only

PollutantLag 0Lag 1Lag 2Mean (0–4)
Results expressed as odds ratios for unit change of pollutant (95% CI).
In addition to pollutant, the individual regression models included the following predictors: 24 hour average outside temperature; date.
Mean (0–4) is five day average.
NO2 24 h ave.
    All children1.010 (0.991 to 1.030)1.018 (0.999 to 1.038)1.033 (1.014 to 1.052)1.043 (1.000 to 1.089)
    Wheezy children1.015 (0.980 to 1.051)1.012 (0.981 to 1.043)1.027 (1.000 to 1.054)1.053 (0.999 to 1.110)
NO2 1 h max.
    All children1.003 (0.993 to 1.013)1.000 (0.989 to 1.010)1.016 (1.003 to 1.030)1.008 (0.975 to 1.043)
    Wheezy children0.996 (0.976 to 1.016)1.001 (0.986 to 1.017)1.004 (0.982 to 1.026)1.004 (0.950 to 1.056)
O3 1 h max.
    All children0.988 (0.975 to 1.001)0.988 (0.974 to 1.002)0.987 (0.975 to 0.998)0.976 (0.954 to 0.999)
    Wheezy children0.979 (0.955 to 1.003)1.000 (0.980 to 1.022)0.983 (0.968 to 0.998)0.977 (0.944 to 1.010)
O3 8 h mma
    All children0.991 (0.976 to 1.005)0.988 (0.972 to 1.002)0.981 (0.968 to 0.995)0.979 (0.954 to 1.004)
    Wheezy children0.983 (0.959 to 1.007)0.994 (0.974 to 1.016)0.989 (0.971 to 1.008)0.986 (0.949 to 1.023)
SO2 24 h ave.
    All children0.987 (0.958 to 1.017)1.007 (0.986 to 1.030)0.992 (0.963 to 1.023)0.972 (0.887 to 1.066)
    Wheezy children0.981 (0.925 to 1.041)0.999 (0.957 to 1.042)0.995 (0.939 to 1.054)1.019 (0.890 to 1.167)
SO42− 24 h ave.
    All children1.062 (0.940 to 1.199)1.029 (0.921 to 1.149)1.038 (0.935 to 1.151)1.090 (0.898 to 1.322)
    Wheezy children1.042 (0.854 to 1.271)1.059 (0.889 to 1.262)0.993 (0.822 to 1.200)1.038 (0.754 to 1.429)
PM10 24 h ave.
    All children1.012 (0.992 to 1.031)1.016 (0.995 to 1.036)1.013 (1.000 to 1.025)1.037 (0.992 to 1.084)
    Wheezy children1.016 (0.986 to 1.047)1.030 (1.001 to 1.060)1.018 (0.995 to 1.041)1.114 (1.057 to 1.174)