Table 1 Linear mixed models for selection of variance-covariance structure for FBS level, JUSH, September 2011 - June 2014
Subject-specific random effect | Linear mixed model |
|---|---|
M1: Random intercept | \(Y_{ij} = \beta _{0} + \beta _{1}\,t_{ij} + \beta _{2}\,t_{ij}^{2} + \sum _{l=1}^{L} \theta _{l}\,x_{ijl} + b_{0_{i}} + \varepsilon _{ij}\) |
M2: Linear random effects | \(Y_{ij} = \beta _{0} + \beta _{1}\,t_{ij} + \beta _{2}\,t_{ij}^{2} + \sum _{l=1}^{L} \theta _{l}\,x_{ijl} + b_{0_{i}} + b_{1_{i}}\,t_{ij} + \varepsilon _{ij}\) |
M3: Quadratic random effects | \(Y_{ij} \,=\, \beta _{0} \,+\, \beta _{1}\,t_{ij} \,+\, \beta _{2}\,t_{ij}^{2} \,+\, \sum _{l=1}^{L} \theta _{l}\,x_{ijl} \,+\, b_{0_{i}} \,+\, b_{1_{i}}\,t_{ij} \,+\, b_{2_{i}}\,t_{ij}^{2} \,+\,\varepsilon _{ij}\) |