elation-matrix" class="section level3">
<h3 class="hasAnchor">
<a href="#working-correlation-matrix" class="anchor"></a>Working correlation matrix</h3>
<p>For our second example we aim to use the proper scoring rules for selecting the working correlation matrix for the AIDS dataset. This is again a longitudinal study on patients with advanced HIV infection. The outcome of interest is the CD4 cell count. Because of the CD4 cell counts can be high, often this outcome is analyzed with a linear mixed model afte