Table 2

Results for initial longitudinal models assessing BMI percentile change among children aged 2–3 in the NLSCY*

Parameter
 Model A
Model B


Estimate
 95% CI
 Estimate
 95% CI
Initial status
 π0i



Intercept
 β00
 62.16
 61.14 to 63.18
 64.84
 63.5 to 66.17
Rate of change
 π1i



Intercept
 β10

-1.36
 -1.83 to -0.89
Random Effects




     Level 2: In initial status
 Math
 119.60
 106.66 to 132.53
 124.72
 105.03 to 144.42
          Covariance
 σ01

-1.80
 -7.07 to 3.48
          In rate of change
 Math

0.94
 -1.14 to 3.02
     Level 1: Within person
 Math
 975.73
 946.37 to 1005.09
 964.62
 933.18 to 996.06
Goodness of Fit




-2 Log Likelihood
88140.50
88102.66

* NLSCY = National Longitudinal Survey of Children and Youth (Canadian); Estimates based on weighted data. Data used are for a cohort of children aged 2–3 at baseline (1994) and assessed bi-annually until 2002.

Oliver and Hayes BMC Public Health 2008 8:16   doi:10.1186/1471-2458-8-16