Logic node and trackers
I am modelling a microsim markov for breast cancer stages. Once the breast cancer reaches a certain stage (local) they have treatment.
When patients are treated in the local state they can opt for : 1) breast conservative surgery, 2) BCS and radiotherapy or 3) mastectomy. From this state they then enter well with history of breast cancer. I can use a tracker for each arm to keep track of what each patient opted for I assume? (this is my first question).
Subsequently, in the well state they are then at risk of a recurrence - this is dependent on the treatment they had (i.e. probability of recurrence for mastectomy < BCS and RT< BCS). I want to use a logic node in the well state to determine the probability that each patient will develop a recurrence which will vary depending on the treatment they had. (my second question is how to do this or is this possible?)
I assume it would be something along the lines of:
1) using a tracker for each treatment (counting 1 if they had a BCS/ RT/Mast) in the local arm
2) using a logic node in the well state and changing the probability of a recurrence using the if command e.g. if(BCS=1;0.3) etc but I don't know the code to do this using three treatments e,g.( if BCS=1, if RT=1, if Mast=1; 0.2; 0.3; 0.4) and then # in no recurrence to make up the remaining probability.
Does this make sense? Would appreciate advice on the code. Cheers
Comments
I believe you can do what you need without too many complications.
With regard to recording the treatment received, I would recommend a single tracker with different values for each of the three treatment options. Perhaps something like this.
t_treatment = 1 (for mastectomy)
t_treatment = 2 (for BCS and radiation)
t_treatment = 3 (for BCS alone)
Then you can check a single tracker to know which treatment was applied.
With regard to the recurrence, I don't think you want a Logic Node. I think a standard chance node with a probability for recurrence would work just fine with a formula variable for the probability of recurrence.
Parameter Variables:
pRecur_PostMastectomy = ?
pRecur_PostBCSRadiation = ?
pRecur_PostBCS = ?
Formula:
pRecurrence = Choose(t_treatment; pRecur_PostMastectomy; pRecur_PostBCSRadiation; pRecur_PostBCS)
Then reference pRecurrence in the model. It will use the appropriate parameter based on the prior treatment.
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