7.1 Setting the model up for Cost-Effectiveness Analysis (CEA)

We will create a new model for this section to show the model setup for Cost Effectiveness Analysis (CEA), before moving to the Get Started Example model CE Decision Tree when we run CEA analysis.

Create a new model:

  • Choose File > New Decision Tree from the menu. You can also use the "+" in the Tree Editor tabs.

  • The Model Setup Wizard will open, and you should select Yes to go through the steps.

The Model Setup Wizard will prompt you for the appropriate cost and effectiveness entries, numeric formatting as well as turn on the cost-effectiveness analyses for your model. The wizard will direct you through a series of Tree Preference categories, prompting you for important information about your model. In the wizard, click Next to move through the prompts, and click Finish when done.

The steps below show you how to set the Tree Preferences through the Model Setup Wizard:

  1. If the Model Setup Wizard is open, move to the next step. If it is not, then go to the Tree menu, select the Model Setup Wizard. The wizard will walk you through the most commonly used settings for your model. We recommend setting every model up with the Model Setup Wizard which can also be accessed via the gear icon in the toolbar.

  2. For a Cost Effectiveness model, we recommend setting the following Tree Preferences via the wizard:

  • Set Calculation Method to Cost-Effectiveness. Click Next.

  • In Cost-Eff Params set a Willingness To Pay (WTP) value (e.g., 50000) and then check the box to "Show Net Benefits in rollback". Click Next.

  • Skip over Payoffs, Discounting and Custom Names by clicking Next each time. We will not change these settings in this specific model.

  • Set Numeric Formatting for the payoff sets. Recommended options are...

    • "For cost" formatting: '0' decimal places and units to Currency.

    • "For effectiveness" formatting: '2' decimal places, units to Custom Suffix and then enter the appropriate suffix, either LY or QALY.

    • Click Finish.

With the CE Calculation method active, as set in the Tree Preferences, the tree will display both Cost and Effectiveness in payoff expressions for Decision Trees, and both payoffs will be active in Markov model. At any time you can change the calculation method back to Simple, where you are usually minimising costs or maximising effectiveness. The Tree Preferences section has more details about this.

If you open the Get Started Example model CE Decision Tree, you can select Tree > Tree Preferences and edit any of the settings as above.

The next sections will look at performing Cost-Effectiveness on a model which is already built. If you need help Building models take a look at these sections: