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Hospital Surge Model Version 1.3: User Manual

Public Health Emergency Preparedness

This resource was part of AHRQ's Public Health Emergency Preparedness (PHEP) program, which was discontinued on June 30, 2011, in a realignment of Federal efforts.

This information is for reference purposes only. It was current when produced and may now be outdated. Archive material is no longer maintained, and some links may not work. Persons with disabilities having difficulty accessing this information should contact us at: https://info.ahrq.gov. Let us know the nature of the problem, the Web address of what you want, and your contact information.

Please go to www.ahrq.gov for current information.

Step 3: Examine the Output

After you specify the number and type of casualties, the model shows you the resources required to treat the patients you specified in Steps 1 and 2.

  • To change one of the scenario parameters and then re-run the Hospital Surge Model, click Previous.
  • To return to the Scenario Selection Screen, click New scenario..
  • To display the User Manual, click Help (note: you may need to disable your pop-up blocker to view the User Manual).
  • To show (or hide) the graphs and tables with the output, click inside any of the four headline bars:

    Four sample headline bars are displayed: Casualty Arrival Pattern at Hospital, Number of Patients in Hospital, Number of Dead and Discharged Patients, and Resources Consumed. The user can select inside the headline bars to expand or collapse each section and view graphs or tables with the output.

  • To save or print a graph, right-click anywhere on the graph. The menu options that will appear vary according to what Web browser you are using, but all will include options for saving, copying, or printing the image.
  • To copy tabular data to a spreadsheet, select the cells with the mouse, right-click in the selected area, select Copy, and then Paste the data into a spreadsheet.
  • To print the entire output page, select File > Print on your Web browser.

The output from a Hospital Surge Model run is organized into five sections:

  • Summary Results.
  • Casualty arrival pattern at your hospital(s).
  • Number of patients in your hospital(s) by day.
  • Number of dead and discharged patients.
  • Resource requirements.

Summary Results

The Scenario Results screen displays three summary measures:

  • The actual total number of casualties arriving at your hospital(s). The number may be less than the number you specified in Step 1, due to rounding.
  • The day that the most casualties arrive at your hospital(s), and the number of casualties that arrive on that day.
    • For the nuclear and chemical scenarios, all casualties arrive on Day 1.
    • For the radiological and biological, and foodborne scenarios, casualties arrive as their symptoms present, which could occur over several days.
  • The day that the most patients are in your hospital(s) and the number of patients that are in your hospital(s) on that day.

The screen below shows the output from a model scenario in which the user specified 80 mild and 40 severe anthrax cases. Clicking inside any of the four headlines will expand or collapse the section.

Scenario Results Screen

Screen shot shows a summary of the results from a specified scenario. In this example, the user views the scenario results of an anthrax attack in which there were 80 mild casualties and 40 severe casualties. The sample data show that Day 4 was the day of peak casualty arrival at the hospital (11 patients) and that Day 14 was the day of the peak number of patients in the hospital (60 patients). The user can expand headline bars to view additional data, including graphs or tables: Casualty Arrival Pattern at Hospital, Number of Patients in Hospital, Number of Dead and Discharged Patients, and Resources Consumed.

Casualty Arrival Pattern at Your Hospital(s)

When you click on the bar labeled "Casualty Arrival Pattern at Hospital," the number of casualties arriving at your hospital(s) by day and casualty severity is displayed, in both graphic and tabular format. An illustrative graphic of a casualty arrival pattern is shown below.

Casualty Arrival Pattern at Hospital

Screen shot of the casualty arrival pattern at a hospital in both graph and table form. The sample data show a rapid increase in arrivals in the first week followed by a tapering over the course of a month.

The model employs two key assumptions regarding casualty arrivals:

  • There are no capacity or resource limitations at your hospital(s).
  • Casualties arrive at your hospital(s) when symptoms present. For the nuclear and chemical scenarios, casualties arrive at your hospital(s) immediately after the attack; for the biological and radiological scenarios, there is a delay between exposure and when symptoms present.

For a complete discussion of assumptions used in the Hospital Surge Model, go to the "Hospital Surge Model Description," which is available at http://www.ahrq.gov/prep/hospsurgemodel/.

Number of Patients in Your Hospital(s) By Day

When you click on the bar labeled "Number of Patients in the Hospital", the number of patients in your hospital(s), by hospital unit and day is displayed in both graphic and tabular format. An illustrative graphic of the number of patients in a hospital(s) is shown below.

Number of Patients in Hospital

Screen shot of the number of patients in the hospital over several weeks. The trend for this sample data shows a rapid increase in the number or patients within the first week, a steady high number of patients for about 2 weeks, and a more rapid decline in number of patients in the next 2 weeks.

The model employs four key assumptions regarding the number of patients in your hospital(s):

  • After patients are admitted to the ED, they are transferred to and from the ICU and floor as necessary. Eventually, patients either die in your hospital(s) or are discharged.
  • There are ten possible "paths" that a patient can take in your hospital(s):
    • ED → discharge.
    • ED → death.
    • ED → floor → discharge.
    • ED → floor → death.
    • ED → floor → ICU → death.
    • ED → floor → ICU → floor → discharge.
    • ED → floor → ICU → floor → death.
    • ED → ICU → death.
    • ED → ICU → floor → discharge.
    • ED → ICU → floor → death.
  • The probability that a particular patient will take each of these paths varies by scenario and the severity of their condition upon arrival at your hospital(s).
  • The patient's assumed length of stay in the ED, in the ICU, and on the floor also varies by scenario and severity condition.

For additional information on assumptions regarding lengths of stay and patient paths, go to the Hospital Surge Model Description.

Number of Dead and Discharged Patients

When you click on the bar labeled "Number of Dead and Discharged Patients", the number of patients in your hospital(s), the cumulative number of deaths to date, and the cumulative number of patients discharged from your hospital(s) to date are displayed in both graphic and tabular form. An illustrative graphic of the number of dead and discharged patients at a hospital is shown below.

Number of Dead and Discharged Patients

Screen shot of the number of dead and discharged patients by day in both graph and table form. The sample data show a rapid increase over the first week in hospitalized patients and deaths (cumulative). After the first 3 weeks, the number of hospitalized patients decreases quickly as the number of discharged patients increases proportionately.

Resource Requirements

Patients arriving at your hospital(s) will require resources (e.g., medical personnel and equipment) and consume other resources (e.g., medical supplies) during their length of stay. When you click on the bar labeled "Resources Consumed", the daily resource requirements for all the patients by resource, day, and hospital unit are displayed in tabular form. You can also graph the daily use of an individual resource by clicking the graph icon on the left-hand side of the page.

Resource Requirements (Tabular Form)

Screen shot shows the resource availability and total daily requirements for the hospital in a table format. The sample data are categorized by resource name, unit measure, category or subcategory, consumable, day of peak need, amount of resource needed on peak day, and daily requirements.

The table displays the following data:

  • Resource name.
  • Resource unit. Units of resource requirements include full-time employees, machine time, and unit of use.
    • Machine time refers to the amount of time needed per patient per day on diagnostic machines (such as a CT scanner).
    • Unit of use is a generic term for a daily dose or other definable amount of a consumable resource, such as a medication or a set of laboratory reagents. For example, the unit of use for antibiotics for anthrax would be two 400 mg doses of intravenous ciprofloxacin or two 100 mg doses of intravenous doxycycline plus one or two additional antibiotics.
  • Resource category and subcategory.
  • Whether the resource is consumable (yes/no).
  • Day of peak use. The day that the greatest amount of the resource is required.
  • Amount of use on peak day. This is the amount of the resource that is required on the peak day.
  • Daily requirements, as computed by the model.

Clicking on the graph icon to the left of the resource name displays the resource requirements for that resource in graphic form.

Resource Requirements (Graphic Form)

Screen shot shows a graph representing the hospital requirements for a specific resource. The sample data show the need for med/surg beds increasing rapidly for the first 10 days, remaining high for the next 2 weeks, then quickly declining over the next 2-3 weeks.

Data are displayed until all patients are either discharged from your hospital(s) or die, with the exception of smallpox and botulinum neurotoxin. In these scenarios, the model only considers patients arriving at your hospital(s) within 30 days of the attack, so the data are shown up to Day 30 only.

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