01 Model inputsIn this component, all model input variables are declared and values are set. The point of this component is to group input variables together and organize them in a logical fashion that can be easily communicated to a user. |
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Load mortality data |
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Load all parameters |
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Update parameters |
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02 Decision modelThis component is the heart of the decision analysis: the implementation of the decision model. In this section of the framework, a function is created that maps model inputs to outputs, via the dynamic and/or stochastic processes that the decision model represents. The model itself could be a decision tree, Markov model, stochastic simulation, and so on. The output stored from the model at this stage should be sufficiently general and comprehensive to accommodate calibration, validation, and the main policy analysis. Constructing the model as a function at this stage facilitates subsequent components of model development and analysis, as these processes will all call the same model function but pass different parameter values and/or calculate different final outcomes from the model outputs. The model function also facilitates the use of parallel computing efforts for computationally intensive tasks, such as calibration and probabilistic sensitivity analysis (PSA). |
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Decision Model |
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Check if the sum of transition probabilities equal to one. |
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Check if transition array is valid |
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03 CalibrationIn this component, the unknown parameters of the decision model are calibrated by matching model outputs to specified calibration targets using a Bayesian approach. The function |
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Generate model outputs for calibration from a parameter set |
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Likelihood |
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Log-likelihood function for a parameter set |
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Evaluate log-posterior of calibrated parameters |
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Evaluate log-prior of calibrated parameters |
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Evaluate posterior of calibrated parameters |
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Evaluate prior of calibrated parameters |
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Sample from prior distributions of calibrated parameters |
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Sample from prior distributions of calibrated parameters |
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04 ValidationIn this component, the calibrated model is internally validated by comparing the predicted outputs from the model evaluated at the calibrated parameters against the calibration targets. The computation of the model-predicted outputs using the MAP estimate is done by inserting the |
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Summarize posterior output |
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05a Probabilistic analysisIn this subcomponent, decision uncertainty is evaluated by propagating the uncertainty through the CEA using probabilistic sensitivity analysis (PSA). The function |
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Generate PSA dataset of CEA parameters |
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05b Deterministic analysisThis subcomponent performs a deterministic CEA, followed by some deterministic sensitivity analysis, including one-way, two-way and tornado sensitivity analyses. The function |
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Calculate cost-effectiveness outcomes |
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One-way sensitivity analysis (OWSA) |
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Two-way sensitivity analysis (TWSA) |
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General |
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Open UserGuide of the package |
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Data |
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Life table for the US in 2015 |
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Base-case parameter set |
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Calibration targets for the Sick-Sicker model |
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Posterior distribution of calibrated parameters |
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Maximum-a-posteriori (MAP) estimate of calibrated parameters |
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Posterior distribution of calibrated parameters |
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PSA object of the cost-effectiveness analysis decision model |
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Cost-effectiveness results from probabilistic analysis |
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