Table 4

 Percent change in the risk of death for a 10 µg/m3 increase in PM10 in 14 US cities

Method% increase95% CI
*More lags of winter temperature (lags 2–4).
†Time stratified approach to matching on season and temperature (rounded to the nearest degree Celsius.
‡Poisson regression analysis with penalised splines to control for season and weather.
More winter temperature lags*
    Two stage0.390.23 to 0.56
    One stage0.320.19 to 0.46
Time stratified with temperature matching†
    Two stage0.390.19 to 0.58
    One stage0.530.34 to 0.72
Poisson regression‡0.400.18, 0.62