MODELLING Flashcards
Definition of Economic Evaluation?
A comparative analysis of alternative courses of actions, in terms of both the costs and outcomes (consequences)
- Economic evaluation is the process of measuring cost-effectiveness [Goodacre, 2002]
Definition of Decision-Analytic Cost-Effectiveness Model?
A statistical method by which to inform a decision process that incorporates cost-effectiveness analysis
What is it important to be aware of in Decision Analysis?
UNCERTAINTY
Decision Analysis looks specifically at decision making under uncertainty, using theories of probability and of expected utility
Objective of Economic Evaluation?
Obtain an estimate of the new treatment’s ICER (treatment effect) compared to the existing treatment
What is the purpose of Modelling in Economic Evaluation?
Use modelling to ‘draw’ patient pathway through treatment intervention or through a disease … in order to obtain estimate of new treatment’s ICER (treatment effect) compared to existing treatment
‘Models are used routinely to guide public policy decisions in many areas that affect human life and health’ (Weinstein et al., 2001)
‘Models ability to synthesise data from multiple sources and estimate the effects of interventions can be invaluable, especially in areas where primary data collection may be infeasible’ (Bennett et al., 2012)
Relationship between Modelling and Clinical Trials?
Modelling allows us to understand what is happening after a clinical trial ends … predict what will happen to the patient (potential effect of the intervention) in the future
- Need to know what will happen to patients when finish trial
Main purposes of Modelling in Economic Evaluation?
- Follow on from clinical trials … predict the potential effect of the intervention/treatment
- Help deal with uncertainty
What is a Clinical Trial?
Clinical Trials are an investigation of a new treatment/intervention on people… an experiment is carried out under controlled conditions to determine in a scientific way which of a number of possibilities is the best
- capture data on costs and effectiveness of a new treatment/intervention
• Randomised clinical trials - “gold standard” method of assessment
Why is drug modelling important in England?
There are no clinical trials on certain drugs … can use information from other settings to create a model-based economic evaluation and estimate potential cost-effectiveness of that intervention
How does modelling help with Uncertainty?
Model the future effects and costs of an intervention
- Probability of something happening to a patient is not 100% … there is a level of uncertainty … but modelling can help to identify the probabilities
BUT: To construct a model based economic evaluation involves using uncertain information … because colliding information from multiple sources
What are the processes of modelling?
- Inputs - Information sources
- Model uses natural history (process) of intervention or disease … capture all the potential steps a patient will follow
- Estimate of ICER … Base Case: model that has the best assumed structure and data
What should a good health model look like?
- Be populated w/ the most appropriate and good quality of clinical data (e.g. from meta-analyses)
- Reflect a realistic and credible picture of current clinical practice
- Use the appropriate comparator(s) … to avoid bias
- Be run for an appropriate time period
- Be valid, transparent and reproducible
- Explore uncertainty
- Be easily interpreted
Definition of Decision Trees?
A flow diagram showing the logical structure of the problem to help people to make better decisions about interventions and treatments
Layout of Decision Trees?
“time flows from left to right” with the branches depicting all the possible patient pathways contingent on particular events
- DECISION nodes [square nodes]
- CHANCE nodes [circle nodes]
- TERMINAL nodes [triangle nodes]
What is a Decision Node?
Represents the alternative CHOICES for decision maker
- Alternatives must be mutually exclusive