Online Appendix
A new technique for evaluating land use regression model and their impact on health
effect estimates
Meng Wang,1,2 Bert Brunekreef,1,3 Ulrike Gehring,1 Adam Szpiro,4 Gerard Hoek,1 and Rob
Beelen1
List of eFigures
eFigure 1 Percent of default (all sites models) and evaluation models (N-1 sites models) for
NO2, PM2.5 and PM2.5 absorbance, in which the above variable categories appeared in each
default or evaluation model at least once. Five variable categories include Population
(residential density, population density and house hold density in 100 to 5000m buffer),
Industrial area in 100 to 5000m buffer, Port area in 100 to 5000m buffer, Natural (natural
area and urban green in 100 to 5000m buffer) and Traffic (traffic density, road length in 50 to
1000m buffer and distance to road)............................................................................................3
eFigure 2 Associations between FVC and exposure to NO2 (expressed as change in %)
estimated by evaluation models based on 39 sites in ten training and test sets. The number of
the data sets was ordered according the increased HV R2 in each data set. The black dots and
bars indicate the mean and 95% confidence interval of the changes of FVC per 10μg/m3. The
red lines refer to the average health estimates in the 40 models................................................4
eFigure 3 Associations between FVC and exposure to PM2.5 (expressed as change in %)
estimated by evaluation models based on 19 sites in ten training and test sets. The number of
the data sets was ordered according the increased HV R2 in each data set. The black dots and
bars indicate the mean and 95% confidence interval of the changes of FVC per 5μg/m3. The
red lines refer to the average health estimates in the 20 models................................................5
eFigure 4 Associations between FVC and exposure to PM2.5 absorbance (expressed as change
in %) estimated by evaluation models based on 19 sites in ten training and test sets. The
1
number of the data sets was ordered according the increased HV R2 in each data set. The
black dots and bars indicate the mean and 95% confidence interval of the changes of FVC per
1 unit/m3. The red lines refer to the average health estimates in the 20 models. .....................6
List of eTables
eTable 1 List of predictor variables for model development, buffer sizes and a priori defined
direction of effect......................................................................................................................7
eTable 2 Statistical descriptive of Pearson correlation coefficients between evaluation model
predictions for PM2.5, PM2.5 absorbance and NO2, and the significance analyzed by
ANOVA. ................................................................................................................................. 8
2
eFigure 1 Percent of default (all sites models) and evaluation models (N-1 sites models) for
NO2, PM2.5 and PM2.5 absorbance, in which the above variable categories appeared in each
default or evaluation model at least once. Five variable categories include Population
(residential density, population density and house hold density in 100 to 5000m buffer),
Industrial area in 100 to 5000m buffer, Port area in 100 to 5000m buffer, Natural (natural
area and urban green in 100 to 5000m buffer) and Traffic (traffic density, road length in 50 to
1000m buffer and distance to road).
3
eFigure 2 Associations between FVC and exposure to NO2 (expressed as change in %)
estimated by evaluation models based on 39 sites in ten training and test sets. The number of
the data sets was ordered according the increased HV R2 in each data set. The black dots and
bars indicate the mean and 95% confidence interval of the changes of FVC per 10μg/m3. The
red lines refer to the average health estimates in the 40 models.
4
eFigure 3 Associations between FVC and exposure to PM2.5 (expressed as change in %)
estimated by evaluation models based on 19 sites in ten training and test sets. The number of
the data sets was ordered according the increased HV R2 in each data set. The black dots and
bars indicate the mean and 95% confidence interval of the changes of FVC per 5μg/m3. The
red lines refer to the average health estimates in the 20 models.
5
eFigure 4 Associations between FVC and exposure to PM2.5 absorbance (expressed as change
in %) estimated by evaluation models based on 19 sites in ten training and test sets. The
number of the data sets was ordered according the increased HV R2 in each data set. The
black dots and bars indicate the mean and 95% confidence interval of the changes of FVC per
1 unit/m3. The red lines refer to the average health estimates in the 20 models.
6
eTable 1 List of predictor variables for model development, buffer sizes and a priori defined
direction of effect
Variable
Buffer size (m)
Directio
n
High and low residential density
100, 300, 500, 1000,
+
5000
Port
300, 500, 1000, 5000 +
Industry
300, 500, 1000, 5000 +
Urban green and natural areas
100, 300, 500, 1000,
-
5000
Road length
50, 100, 300, 500,
+
1000
Major road length
50, 100, 300, 500,
1000
Traffic intensity in the nearest road
NA
+
(Squared) Inverse distance to the nearest road
NA
+
(Squared) Invest distance to the nearest
NA
+
Traffic intensity in the major road
NA
+
(Squared) Inverse distance to the nearest major
NA
+
NA
+
Total traffic load of roads in a buffer (sum of
50, 100, 300, 500,
+
(traffic intensity * length of all segments))
1000
Total traffic load of major roads in a buffer
50, 100, 300, 500,
(sum of (traffic intensity * length of all
1000
road*traffic intensity in the nearest road
road
(Squared) Invest distance to the major road
*traffic intensity in the major road
+
segments))
Population
100, 300, 500, 1000,
+
5000
Urban green
100, 300, 500, 1000,
-
5000
NA: not applicable.
7
eTable 2 Statistical descriptive of Pearson correlation coefficients between evaluation model
predictions for PM2.5, PM2.5 absorbance and NO2, and the significance analyzed by ANOVA.
Pollutants
Minimum
Maximum
Median
p-value
PM2.5
-0.27
0.99
0.75
<0.01
PM2.5 absorbance
0.36
0.99
0.94
>0.05
NO2
0.58
0.99
0.98
>0.05
8