Table 1 is provided as a reference for input values for your model.
|
Table 1. Input Variable for Scenario Analysis
|
|
Variable Name
|
Description
|
Base
|
Best
|
Worst
|
|
Pr_PROB
|
Per-act HIV infection without PEP
|
0.02
|
0.03
|
0.006
|
|
Pr_PREV
|
Partner is HIV-infected
|
0.18
|
1
|
0.06
|
|
Pr_ADHERE1
|
Patients' adherence to full course of therapy
in absence of side effects
|
0.79
|
0.84
|
0.68
|
|
Pr_ADHERE2
|
Patients' adherence to full course of therapy
when side effects occur
|
0.59
|
0.68
|
0.5
|
|
Pr_PEPE
|
Effectiveness of full course of PEP
|
0.79
|
0.94
|
0.43
|
|
Pr_SIDE
|
Probability of PEP side effects
|
0.5
|
0.2
|
0.8
|
|
r
|
Discount rate
|
3%
|
0
|
5%
|
|
C_PEP
|
Cost of PEP per person
|
$679
|
$439
|
$1,048
|
|
Q_SIDE
|
QALYs lost due to side effect
|
0.005
|
0
|
0.02
|
|
Note:C_HIVMC, Q_HIV and Q_NOHIV are functions of discount rate and annual values; they will vary in accordance with the discount rate r.
C_HIVMC = NPV(r;0; 0; 3267; 9303; 9303; 9303; 16167; 16167; 16167; 17835; 17835; 17835; 17835; 25729; 49010; 49010)*172.2/156.9
Q_HIV = NPV(r;0.940; 0.940; 0.910; 0.870; 0.870; 0.870; 0.820; 0.820; 0.820; 0.760; 0.760; 0.760; 0.760; 0.650; 0.620; 0.620)
Q_NOHIV = PV(0.940; 0; r; 39)
|
Note: You do not need to make best and worst case variables for C_HIVMC, Q_NOHIV and Q_HIV. These values are functions of the discount rate. They will change as a function of the best and worst case discount rates.
Remember to save different versions of your tree if you want to make changes to your base tree to save time.
Answer the following questions. Please type your answers.
1. Consider variables: Pr_Prob and Pr SIDE. Explain why a relatively high value for the former and a relatively low value for the latter are the input values for the BEST case.
2. Please completetable 2 below.
3. Please describe generally what a best and worst case scenario analysis is and why we conduct them.
4. Explain the results presented in your table to a policy-maker.
Table 2: Base, Best and Worst Case Results
|
Scenario
|
Cost
|
Incremental
Cost
|
Effects
|
Incremental Effect
|
ICER
|
|
Base Case
|
|
|
|
|
|
|
PEP
|
|
|
|
|
|
|
No-PEP
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Worst
|
|
|
|
|
|
|
PEP
|
|
|
|
|
|
|
No-PEP
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Best
|
|
|
|
|
|
|
PEP
|
|
|
|
|
|
|
No-PEP
|
|
|
|
|
|