Mass Trauma Casualty Predictor
In the confusion that often follows a mass trauma event, managing a hospital can be challenging. Past mass trauma events show patterns of hospital use. It is possible to estimate initial casualty volume and pattern after a mass trauma event. Public health professionals and hospital administrators can use this information to handle resource and staffing issues during a mass trauma event.
Patterns of Hospital Use
- Within 90 minutes following an event, 50-80% of the acute casualties will likely arrive at the closest medical facilities.
- Other hospitals outside the area usually receive few or no casualties.
- The less-injured casualties often leave the scene under their own power and go to the nearest hospital. As a result:
- They are not triaged at the scene by Emergency Medical Services (EMS).
- They may arrive to the hospital before the most injured.
- On average, it takes 3-6 hours for casualties to be treated in the emergency department (ED) before they are admitted to the hospital or released.
Casualty Predictor
When trying to determine how many casualties a hospital can expect after a mass trauma event, it is important to remember that casualties present quickly and that approximately half of all casualties will arrive at the hospital within a 1-hour window.
- This 1-hour window begins when the first casualty arrives at the hospital.
- To predict the total number of casualties your hospital can expect, double the number of casualties the hospital receives in the first hour.
Casualty
Predictor
Total Expected Casualties
= (Number of casualties arriving in one hour window) x 2
Note: The total expected number of casualties will be
an estimate. There are many factors that may affect the accuracy of this prediction such as: transportation difficulties and delays, security issues that may hinder access to victims, and multiple explosions or secondary effects of
explosion (such as a building collapse).

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Page content last
revised 3/17/03.
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