Table 2

explanatory variables used in all models.

Variable
Description

Lagged PM10
Estimated ambient PM10 for each single-day lag 0, 1, 2 or 3 in (μg/m3)
Indigenous
An index of counts for indigenous status where indigenous = 1 and non-indigenous = 0
Time
Time in days, represented by a natural cubic spline with 40 df (4 df per dry season)
AvDailyTemp
Average daily temperature (calculated by averaging the max and min temperatures), in Degrees Celsius (°C), with 6df
AvDailyTempLag1-3
Moving three-day averages of daily temperatures (lags 1, 2 and 3), with 6df
RHumAv
Average daily relative humidity in percent (%) with 3df
RHumAvLag1-3
Moving three-day averages of daily relative humidity (lags 1, 2 and 3), with 3 df
DOW
Day of the week. Factor with 7 levels
FluEpidemic
Influenza epidemics. Dummy for days above the 90th centile
ICD10change
The change between ICD editions. Dummy variable indicating the changeover
Holidays
Dummy variable for public holidays
Population
The estimated yearly population for indigenous or non-indigenous residents included as an offset

Hanigan et al. Environmental Health 2008 7:42   doi:10.1186/1476-069X-7-42