# Change Jump State based on Cycle Number

I have a tree where the marvkov node has 3 jump states A, B, and death. I'm going to be doing a microsimulation. I'd like to have an individual run through branch A for 12 cycles, and then branch B for the remaining 40 cycles.

## Comments

Andrew MunzerTreeAge Pro includes the cycle counter keyword _stage in Markov models. The value of _stage starts at 0 then increments to 1, 2, etc. for each subsequent cycle.

You can probably use the _stage counter in your model in a probability formula to move patients from one state to another based on the number of cycles.

Adriana CollingsI tried this but when assigning probabilities on the tree, it is only assigning initial probabilities - therefore I am not sure where to include the equation

Andrew MunzerI think you are trying to put those probabilities under the health states.Those initial probabilities are only used once to seed the health states at the start of the analysis.

Time-dependent probabilities only make sense for events to the right of the health states. I recommend you review Section 37.1 in the Help Documentation. This describes how to create a time-dependent probability under an event in a Markov model.

AkHi Andrew,

I have a similar concern. I would like to have different cohorts at the jump state to use as a PSA. Please is there a way to do this in Treeage? I know excel works with the RAND() command.

Andrew MunzerThe initial probabilities for states require the same kind of probability expressions as other event probabilities in the model.

You can use a beta distribution to represent any probability in the model for use in PSA. Then use the hashtag for the complimentary probability.

If you have multiple branches with probabilities, you can use a Dirichlet distribution to generate all the probabilities.

Andrew

AkThank you Andrew for your feedback, it worked.

Regards,

Akwasi

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