Summary
The Archimedes Model is a powerful tool that can be used to answer clinical and administrative questions that cannot be addressed by clinical trials (they would be too costly and take too much time) or expert opinion (the human mind can't accurately sort, weigh and integrate many variables).
The Archimedes Model is a comprehensive, continuous simulation model of health care developed at Kaiser Permanente. It can be used to explore the effects of a wide variety of health care interventions on the progression, logistics, and economic outcomes of major diseases in a complex health care system. The simulation is at the level of biological, clinical and administrative detail at which interventions have their effects and clinical decisions are made. Potential applications include the design of guidelines, analysis of best practices, estimation of return on investment of care management programs, setting of clinical targets, priority setting, strategic goals, forecasting, design of performance measures, and research design.
What is the Archimedes Model?
How does the Archimedes Model differ from other models?
What are the model's advantages?
What types of questions can the Archimedes Model help answer?
How has the Archimedes Model been validated?
Will the Archimedes Model replace clinical trials
What is the Archimedes Model?
The Archimedes Model is a simulation model that creates a virtual reality in which all the important objects and events in the real world have corresponding objects and events in the model's world. When a simulation model is run, the objects interact and events occur as they would in the real world.
The Archimedes Model can simulate a health care system of virtually any size.
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How does the Archimedes Model differ from other models?
The Archimedes Model differs from other models in that it includes virtually all aspects of care, including member/patients, diseases, providers, interventions, facilities, equipment and supplies, policies and protocols, and finances. Each of these features is included in a high level of detail, attempting to reproduce the biological and clinical events at the level of detail at which physicians think and clinical management decisions are made. Archimedes is also unique in health care in that it is a true continuous time model; any event can occur at any time.
The Archimedes Model has unmatched:
- Depth - for example, it approaches blood pressure from the Starling curve, end diastolic volume, right atrial pressure, mean arterial filling pressure.., etc.
- Breadth - demographics, epidemiology, biology, behavior outcomes, logistics, costs
- Validation - reproduces clinical trials through the biology of the disease
- Power - analyzes problems at the level of detail and flexibility at which clinical and administrative decisions are actually made
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What are the model's advantages?
The Archimedes Model creates a virtual world that can simulate and "experiment" with different interventions and/or different assumptions, either individually or in combination, and explore the effects on all the important health, logistic, or economic outcomes. The speed and degree with which any intervention is implemented can be specified. For example, to estimate the potential of a proposed program, we might change the behavior of the simulated patients and doctors instantaneously and completely. Or, to simulate more realistic scenarios, their behavior changes gradually or imperfectly. Time is sped up in this virtual world. We can run many different combinations of interventions and compare them with current practice and with each other. The results can highlight not only what happens (e.g., "The net savings will be about $1.2 million."), but also why it happens (e.g., the breakdown of each budget center and which specific interventions produced which effects).
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What types of questions can the Archimedes Model help answer?
The following are examples of the types of questions the model can help answer:
- A prominent clinic publishes a new protocol to evaluate patients with chest pain and decides whom to admit. At the Mayo clinic it reduced costs 30% without harming quality. However, the protocol that was previously used at the Mayo clinic, and against which their comparison was made, was quite different than the way chest pain patients are currently managed. If this new protocol were to be used in our system, what effect would it have on our quality and cost?
- What actual difference does it make - in morbidity, mortality and costs - if we increase by 10 percentage points the proportion of patients who get an annual lipid profile?
- Physicians are complaining that they do not have enough time in their brief visits to do all the things they are asked to do. What are the five most important things for them to concentrate on?
- A specialty society has just revised its guidelines for a disease. What difference does it make?
- How many heart attacks in years 1, 3 and 5 will be prevented if we lower the average HbA1C from 8.5% to 8.0%? What is the impact on drug, office visits and hospitalization costs?
- Which of the key process measures related to diabetes (e.g., HbA1C test, eye exam, lipid profile) will have the greatest impact on outcomes?
- We can hire 10 new case managers next year. Should they be put on CAD, CHF, diabetes, asthma, cancer..?
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How has the Archimedes Model been validated?
The core equations of the model – those that describe the progression of diseases and how they respond to treatments – are validated by simulating actual clinical trials. This is a very deep validation that tests the entire chain of events from the fundamental biology and pathology of the disease, to the development of symptoms, patient behavior in seeking care, performance of tests, and delivery of treatments; to the changes in biological and health outcomes.
We found that the results of 71 of 74 trial comparisons (between the real-world clinical trial and the Archimedes Model's simulated trial) were well within the sampling error. The other three either just missed or the description of the trial was incomplete. Of the 74 trials, 54 were within +/- 1 standard deviation. For all 74 exercises: r = 0.99.
For some of the trials, some of the data from the trial were used to help build parts of the model. The other trials were 100 percent independent. For the exercises not used to build the model (100 percent independent), the correlation between the model and trial was still extremely high, with r = 0.99.
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Will the Archimedes Model replace clinical trials?
The Archimedes Model was not developed to replace clinical trials. Clinical trials remain better than any other method for collecting information (not only the Archimedes Model, but expert judgment or clinical intuition) because they require no assumptions beyond assumptions about the design of the trial, and they can find totally unexpected outcomes. But if you can't do a clinical trial, we believe the Archimedes Model is your best alternative.
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