Table 3

Multilevel linear regression associations of the change in availability of major chain fast-food outlets and body mass index from wave I to wave III (n=882)

VariableModel 1Model 2Model 3
Major chain fast-food outlets within 2 km 
Coefficient (95% CI)
Major chain fast-food outlets within 3 km 
Coefficient (95% CI)
Major chain fast-food outlets within 5 km 
Coefficient (95% CI)
Intercept26.84 (25.92 to 27.77)***27.19 (26.21 to 28.18)***27.48 (26.54, 28.43)***
Time (years)0.10 (0.03 to 0.16)**0.09 (0.01 to 0.16)*0.08 (0.01 to 0.16)*
Fast-food availability exposure
 Number of outlets−0.07 (−0.23 to 0.08)−0.04 (−0.12 to 0.05)−0.02 (−0.07 to 0.02)
 Change in outlets0.01 (−0.44 to 0.46)−0.17 (−0.41 to 0.06)−0.11 (−0.27 to 0.04)
 Change in outlets and time interaction−0.001 (−0.023 to 0.021)0.008 (−0.013 to 0.029)0.006 (−0.003 to 0.015)
Potential confounders†
 Age at baseline0.08 (0.02 to 0.13)**0.08 (0.02 to 0.14)**0.08 (0.02 to 0.13)**
 Education
  Medium−0.38 (−0.99 to 0.24)−0.35 (−0.97 to 0.26)−0.35 (−0.96 to 0.27)
  High−1.12 (−1.88 to –0.36)**−1.09 (−1.85 to –0.33)**−1.06 (−1.83 to –0.30)**
 Employment
  Part-time−0.24 (−0.54 to 0.06)−0.24 (−0.54 to 0.06)−0.24 (−0.54 to 0.06)
  Not in employment−0.09 (−0.44 to 0.27)−0.08 (−0.44 to 0.28)−0.09 (−0.44 to 0.27)
 Household income
  $500 to <$1000−0.11 (−0.60 to 0.39)−0.11 (−0.61 to 0.38)−0.11 (−0.61 to 0.38)
  $1000 to <$1500−0.02 (−0.51 to 0.48)0.01 (−0.50 to 0.48)−0.01 (−0.50 to 0.48)
  $1500+−0.01 (−0.55 to 0.52)0.002 (−0.53 to 0.54)0.01 (−0.53 to 0.55)
 Children in household
  No−0.20 (−0.62 to 0.22)−0.19 (−0.62 to 0.23)−0.18 (−0.60 to 0.24)
  Urban
  Rural0.31 (−0.49 to 1.12)−0.01 (−0.92 to 0.90)−0.32 (−1.20 to 0.55)
VarianceVarianceVariance
Intercept33.91 (29.15 to 39.43)33.80 (29.10 to  39.27)33.62 (28.89 to 39.12)
Slope0.05 (0.02 to 0.10)0.05 (0.02 to 0.10)0.05 (0.02 to 0.10)
Residual2.58 (2.08 to 3.20)2.57 (2.07 to 3.19)2.57 (2.08 to 3.19)
CovarianceCovarianceCovariance
Intercept, slope§0.24 (−0.06 to 0.87)0.24 (−0.06 to 0.86)0.24 (−0.06 to 0.87)
  • †Reference categories: low education, full-time employment, <$500, yes children in household, urban.

  • Age was centred at 37 years.

  • § Considers covariance between these random components.

  • *p<0.05; **p<0.01; ***p<0.001.