Skip to main content

Table 3 Unadjusted mean BMI z-scores within tertile of environmental exposure, with tests for trend

From: Associations between BMI and home, school and route environmental exposures estimated using GPS and GIS: do we see evidence of selective daily mobility bias in children?

   Mean BMI z-score per exposure tertile (Pearson’s correlation co-efficient)
  Tertile Home School Modelled journey Actual journey
All food outlets 1 (least exposed) 0.606 1.031 0.852 0.811
  2 0.710 0.592 0.700 0.979
  3 1.157 (0.208)** 1.018 (−0.081) 0.863 (−0.053) 0.671 (−0.104)
Takeaway food outlets 1 (least exposed) 0.722 1.031 0.924 0.737
2 0.590 0.592 0.613 0.877
3 1.161 (0.207)** 1.018 (−0.091) 0.790 (−0.060) 0.851 (−0.142)
Physical activity facilities 1 (least exposed) 0.593 1.179 0.721 0.551
2 0.903 0.324 1.061 (0.052) 0.727
3 0.967 (0.177)* 0.681 (−0.140) - 1.197 (0.104)
Green space 1 (least exposed) 0.982 0.506 1.012 0.930
  2 0.651 0.681 0.761 0.859
  3 0.828 (−0.068) 1.379 (0.291)*** 0.690 (−0.024) 0.676 (−0.131)
Density of fatal road traffic accidents 1 (least exposed) 0.836 0.926 0.795 0.570
2 0.763 (−0.084) 0.681 (−0.094) 0.885 (−0.122) 0.857
3 - - - 1.038 (−0.020)
Proportion of roads that are major roads 1 (most walkable) 0.655 0.640 0.765 0.862
2 1.306 0.976 0.617 0.557
3 0.952 (0.094) 0.747 (0.095) 1.085 (0.126) 1.056 (0.062)
Effective walkable area/Route length ratio (for journeys) 1 (least walkable) 0.548 1.379 1.066 0.773
2 0.808 0.681 0.663 0.850
3 1.110 (0.180)* 0.506 (−0.289)*** 0.743 (−0.083) 0.842 (0.071)
Connected node ratio 1 (least connected) 0.655 1.031 - -
2 0.905 0.681 - -
  3 0.912 (0.027) 0.843 (−0.059) - -
Herfindahl-Hirschmann Index 1 (least mixed) 0.559 1.031 0.554 0.506
2 0.886 0.976 1.055 1.064
  3 1.020 (0.175)* 0.413 (−0.171)* 0.849 (0.113) 0.888 (0.113)
  1. ***p < 0.01, **p < 0.05, *p < 0.1, with reference to test for trend (Pearson’s correlation analysis) between environmental exposure and BMI z-score.