NISAC Tools: HCSim
HCSim: Agent-Based Healthcare Surge Capacity Model
The HCSim model is used to gauge the impact of mass-casualty incidents on hospital capacity.
Disease cases or casualties carry information about their disease and treatment states. These states are transformed by a stochastic disease progression model. Patients are allocated to the nearest available resources depending on their condition.
HCSim was originally developed to model scenarios involving an improvised nuclear device (IND). A version of HCSim was recently adapted to predict the impact on hospital surge capacity from a national influenza pandemic.
Conceptual view of an IND incident showing blast and fallout areas along with the incident population and local hospitals (Click graphic to enlarge)
Application to an Improvised Nuclear Device Incident
Hospital agents admit and process patients based on their condition until they either recover or die.
To model IND incidents, information on blast effects and fallout is introduced from standard models. This information manifests as casualties exposed to radiation at various levels. The model then follows these cases to assess their impact on local hospital resources.
Application to Pandemic Influenza
Submodels and their relationships in the application of HCSim to IND incidents (Click graphic to enlarge)
For pandemic influenza, hospital resources are aggregated to the county level.
Case incidence data is provided by a national-scale epidemic model. Patients are transported to the nearest county with available resources, and the impact on national hospital capacity, especially critical care facilities, is followed.
Confidence in the Model
HCSim is a relatively new capability still in development.
Results for the two types of applications shown here have been presented at several high-level workshops and forums, where they have been subjected to expert scrutiny. As a result, NISAC’s confidence in the model for these applications is relatively high.
Comparing the percentage of occupancy of hospital beds in the days following an IND incident in a major metropolitan area under three different hospital admission policies: permissive (top), moderate (middle) and highly restrictive (bottom) (Click graphic to enlarge)