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A Meta-Analysis Package for R

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analyses:berkey1998

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analyses:berkey1998 [2023/06/01 12:30] Wolfgang Viechtbaueranalyses:berkey1998 [2023/06/22 11:42] (current) Wolfgang Viechtbauer
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 A multivariate random-effects model can now be used to meta-analyze the two outcomes simultaneously. The model is given by $$\left[ \begin{array}{c} A multivariate random-effects model can now be used to meta-analyze the two outcomes simultaneously. The model is given by $$\left[ \begin{array}{c}
-   y_{AL,i}\\ +   y_{PD,i}\\ 
-   y_{PD,i}+   y_{AL,i}
 \end{array} \right] \end{array} \right]
    =    =
 \left[ \begin{array}{c} \left[ \begin{array}{c}
-   \mu_{AL} \\ +   \mu_{PD} \\ 
-   \mu_{PD}+   \mu_{AL}
 \end{array} \right] \end{array} \right]
        
 \left[ \begin{array}{c} \left[ \begin{array}{c}
-   u_{AL,i} \\ +   u_{PD,i} \\ 
-   u_{PD,i}+   u_{AL,i}
 \end{array} \right] \end{array} \right]
        
 \left[ \begin{array}{c} \left[ \begin{array}{c}
-   \epsilon_{AL,i} \\ +   \epsilon_{PD,i} \\ 
-   \epsilon_{PD,i} +   \epsilon_{AL,i} 
-\end{array} \right],$$ where $$\mbox{Var}+\end{array} \right],$$ where $$G = \mbox{Var}
 \left[ \begin{array}{c} \left[ \begin{array}{c}
-   u_{AL,i} \\ +   u_{PD,i} \\ 
-   u_{PD,i}+   u_{AL,i}
 \end{array} \right] \end{array} \right]
    =    =
 \left[ \begin{array}{cc} \left[ \begin{array}{cc}
-   \tau^2_{AL}              & \rho \tau_{AL} \tau_{PD} \\ +   \tau^2_{PD}              & \rho \tau_{PD} \tau_{AL} \\ 
-   \rho \tau_{AL} \tau_{PD} & \tau^2_{PD+   \rho \tau_{PD} \tau_{AL} & \tau^2_{AL
-\end{array} \right]$$ and $$\mbox{Var}+\end{array} \right]$$ and $$V_i = \mbox{Var}
 \left[ \begin{array}{c} \left[ \begin{array}{c}
-   \epsilon_{AL,i} \\ +   \epsilon_{PD,i} \\ 
-   \epsilon_{PD,i}+   \epsilon_{AL,i}
 \end{array} \right] \end{array} \right]
    =    =
 \left[ \begin{array}{cc} \left[ \begin{array}{cc}
-   \mbox{var}_{AL,i}      & \mbox{cov}_{AL,i;PD,i} \\ +   \mbox{var}_{PD,i}      & \mbox{cov}_{PD,i;AL,i} \\ 
-   \mbox{cov}_{AL,i;PD,i} & \mbox{var}_{PD,i} +   \mbox{cov}_{PD,i;AL,i} & \mbox{var}_{AL,i} 
-\end{array} \right],$$ where the elements in this second variance-covariance matrix are given by the $2 \times 2$ blocks along the diagonal in the ''V'' matrix. We can fit this model with:+\end{array} \right],$$ where the elements in this second variance-covariance matrix are given by the $2 \times 2$ blocks along the diagonal in the ''V'' matrix. Therefore, $$V = \left[ \begin{array}{ccc} 
 +   V_1 &        & \\ 
 +       & \ddots & \\ 
 +       &        & V_5 
 +\end{array} \right].$$  
 + 
 +We can fit this model with:
  
 <code rsplus> <code rsplus>
analyses/berkey1998.txt · Last modified: 2023/06/22 11:42 by Wolfgang Viechtbauer