Budget Impact Analysis on Cost Effectiveness models

TreeAge Pro makes it easy to create Cost Effectiveness (CE) models that report outputs in addition to Cost and Effectiveness. This means you don’t need additional models to capture additional outcomes.

In the case of using your CE model in Budget Impact Analysis, this article shows you how to:

  • Add a population size to your CE model
  • Create an additional payoff to capture the Budget Impact for your population.
  • Review those BI outputs when running CE Analysis.

We describe the steps to adjust this Markov Decision model attached: “Example09-MarkovCancerDecision.trex”.

  1. Create additional payoffs to capture the BI outputs
    • Open the model and use the Tree Menu to open Tree Preferences.
    • Select Calculation > Payoffs.
    • See that “Calculate extra payoffs” is checked and increase the Number of enabled payoffs from 5 to 6. (Payoffs are also referred to as Rewards).
    • Select Payoffs > Custom Names and now give Payoff  #6 the name “BI_TotalCost”.
    • Select “Apply and close”.
  2. Create a variable to capture the population size
    • Open Variable Properties View and select the green “+” to create new variable
    • In the Add/change variable dialogue, name the variable “BI_population” and define the cohort as 1000.
    • Select “Apply and close”.
  3. Add the calculations for the BI outputs via the NEW payoff
    • Select Markov Node for Tx 1 in the tree editor and then open Markov Info View.
    • Select Health States Tab and expand Rewards (Inactive Set).
    • Each entry in the BI_TotalCost (Payoff #6) should be the same as the Cost (Payoff #1) multiplied by BI_population.
    • For example,
      • Cost payoff Init cost = 0.5 * ( cLocal )
      • BI_TotalCost payoff Init BI_TotalCost = 0.5 * ( cLocal ) * BI_population
    • Make sure that you copy all of the entries between Payoff #1 and Payoff #6 (Init, Incr and Final)

Now your model is ready to perform both CEA and BI analysis.

  • To run CEA: Select Analysis > Rankings report. You will see CE, ICER and other rewards, specifically the last column is BI_TotalCost which is a cumulative cost of treatment for the entire cohort.
  • To run BI only: Change the model Tree Preferences to the Simple Calculation method.
    • Open Tree Preferences > Calculation Method and select Simple.
    • Select Active Payoff as #6.
    • Apply and Close.
    • Now when you run Analysis > Rankings, the model will calculate BI total cost by default.

The completed model is attached: “Example09-MarkovCancerDecision-WithBudgetImpact.trex”.

Additional reporting

An interesting report for Budget Impact over period of time is generated by Selecting a Markov Node and running the Markov Cohort Report (you can run cohort reports only on individual Markov nodes).

  • Check Tree Preferences are set to Simple Calculation method with Payoff #6 Active.
  • Select Top strategy Markov node.
  • Via the Analysis Menu select Markov Cohort Extended Report.
  • Open the Charts to see summary, stage and cumulative reports for details of Budget Impact by year.


We will further enhance this model in another article to show how to introduce new cohorts of patients into the model over subsequent years.  This will show an Entry Node, a new feature of Dynamic Cohort Models in TreeAge Pro. 

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  • HI guys,

    I really need a demonstration of a Budget impact using an Entry Node with dynamic cohort. I tried to do it alone but it didn`t work well.
    Could you help us?



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  • Ricardo

    Thanks for the question. You can submit your question with some details to our support desk and then we can help you. We can always post the response here to assist others.


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