Pharmacometric model development most often progresses in a hierarchical fashion, using the likelihood ratio test to assess significance of improved fit between nested models. An appropriate visualization of the model hierarchy can help in gaining a better understanding of key stages in model building, and can aid in communicating the model development history to others.
Pirana can generate a visual run record (VRR) for visualizing the model building process from initial to final model. The VRR is an SVG file that contains in interactive tree view of the model development process. Models are related to each other based on Pirana’s reference model tags in the model file.
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Select the Results > Run records > Visual run record menu option.
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Select a final model.
Colors aid in visualizing the improvement/worsening of model fit (green/red), and whether the model has children or not. In each branch, the nodes are ordered by OFV. When a final model is specified, the modeling path can be made visible as a blue line, thereby easily identifying the key runs.
