Building a Treeage Markov Model

QALY Distributions
Assume normal distribution (mean, SE)
Assume SD = 0.1
Assume N for calculating SE is same as the number of
individuals observed making the transitions reported in
the Table on slide 24
RtoR: 0.9, 0.0130; RtoA: 0.8, 0.0156
AtoR: 0.8, 0.0123; AtoA: 0.7, 0.0035
AtoF: 0.6, 0.0134; AtoD: 0.35, 0.0333
FtoA: 0.6, 0.0213; FtoF: 0.5, 0.0236
FtoD: 0.25, 0.0158
17. For example, to create outcomes for the Remission terminal node of the Remission subtree, first
create the distributions for the outcomes: click “Values/Distributions/new/Poisson”(Poisson because the
slide above says to use Poisson distributions for the number of hospitalizations), type “0.05" in the white
box labeled lambda (from the hypothetical table above of the number of hospitalizations for going from
Remission to Remission), click “OK,” name the distribution “dhRR,” describe the distribution as
“Distribution of number of hospitalizations, Remission to Remission,” and click “OK.” For the next
distribution click “Values/Distributions/new/Normal,” type “10,000" in the white box labeled Mean and 100
in the white box labeled Std Dev (from the slide above describing the cost of hospitalization), click “OK,”
name the distribution “dcHosp,” describe the distribution as “Distribution of the cost of hospitalization,” and
click “OK.” Use similar steps and the information in the slide immediately above to create a distribution for
the number of QALYs gained for going from Remission to Remission and name this distribution dqRR. To
put these distributions in the Markov model, “select the first terminal node, right click the terminal node,
select “Markov Transition Rewards,” type in the box for Transition Rwd 1 (which is labeled “Cost:”)
“(dhRR*dcHosp)/(1+r)^t,” type in Transition Rwd 2 (which is labeled “Effect;) (dqRR/(1+r)^t,” and click
“OK.”
Create and insert other distributions for the transition rewards for the remaining terminal nodes in the
Usual Care Markov node.
Transfer information from the Usual Care Markov node to the Intervention Markov node, and
modify it.
18. Start by deleting the subtree following the existing Intervention Markov node: right click the
Intervention Markov node, click “Select Subtree,” right click again, and click “Cut Subtree.” Right click the
Usual Care Markov node, click “Select Subtree,” right click again, click “Copy Subtree,” right click the
Intervention Markov node, and click “Paste nodes.”
19. There are two differences between the Usual Care and the Intervention Markov nodes. The transition
probabilities in the Remission subtree are different and the cost of the intervention must be added to the
outcomes in the Intervention model. To make these changes, start by creating a distribution for the
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