help for ascot
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Title

    ascot -- A Severity Characterization of Trauma


Version

    Version 3.0.

    ICDPIC Version 3.0 requires STATA 8.0 or higher.  ICDPIC Version 3.0 has
    been tested in STATA 10 and STATA 11, but the authors believe it should
    also work without incident in STATA 8 and STATA 9.  If you have any
    problems using ICDPIC Version 3.0 in STATA 8 or STATA 9, please inform
    the authors.

    ICDPIC Version 3.0 may be installed from within STATA using the ssc
    command.  If you installed a previous version of ICDPIC from the SSC
    archives website using the ssc command, we suggest that you first delete
    it by typing ssc uninstall icdpic followed by ssc install icdpic.
    Alternatively, you may use ssc install icdpic, replace.  See help for 
    ssc.

    If you installed any previous ICDPIC files obtained directly from the
    authors, please delete them ALL (.ado, .hlp and .dta files) to avoid any
    conflicts with ICDPIC 3.0 files.

    Please enter complete variable names in the ICDPIC Version 3.0 dialog
    boxes.  Do not use abbreviations.

    New to Version 3.0 is the addition of a dialog box (.dlg) file associated
    with each individual ICDPIC Version 3.0 program (.ado) file.  To access
    the ICDPIC dialog box, and all the ICDPIC programs, type: db icdpic.
    Typing icdpic, as in earlier versions, will still work, but ONLY with
    icdpic.  For example, to access the ASCOT program directly, type: db
    ascot.  Typing ascot, as in previous versions, will produce an error.

    Fixed in ICDPIC Version 3.0 is the ability to use path\file names
    containing spaces.

    Fixed in ICDPIC Version 3.0 is the ability to run in STATA 11.0.

    Fixed in ICDPIC Version 3.0 is a bug that caused the triss program to
    crash if the rts variable was named anything other than "rts".

    New in ICDPIC Version 3.0 (trauma program only) is the ability to choose
    whether an AIS value of 6 automatically forces an ISS of 75 or to
    automatically have all AIS values of 6 changed to an AIS value of 5 and
    then have the ISS calculated normally.

    All dialog boxes in ICDPIC Version 3.0 have memory.  Each time a dialog
    box is opened within the same STATA session, it will remember the values
    last entered.

    All dialog boxes in ICDPIC Version 3.0 have the following buttons:

      OK executes the program and removes the dialog box from the screen.

      SUBMIT executes the program and leaves the dialog box on the screen.
             Note that if an error message is generated the dialog box may be
             minimized.

      CANCEL removes the dialog box from the screen and does nothing.
             Clicking on the close icon of the dialog box does the same
             thing.

      HELP leaves the dialog box on the screen and presents the program help
           file.  The HELP button has a question mark on it.

      COPY leaves the dialog box on the screen and copies the program command
           to the clipboard.

      RESET resets the values of the controls in the dialog box to their
            initial state, just as if the dialog box were invoked for the
            first time.  Each time a user invokes a dialog box, its controls
            will be filled in with the values the user last entered.  RESET
            restores the control values to their defaults.  The RESET button
            has an R on it.


Syntax

        db ascot

    The ASCOT (A Severity Characterization of Trauma) dialog box will open.
    Follow the instructions.

                                      OR

        db icdpic

    The ICDPIC dialog box will open.  Choose ASCOT and click OK or Submit.
    The ASCOT (A Severity Characterization of Trauma) dialog box will open.
    Follow the instructions.


Description

    ascot estimates patient survival probability,


                              Ps = 1/(1 + exp(-K))


    where


   K = k1 + k2(CGCS) + k3(CBP) + k4(CRR) + k5(A) + k6(B) + k6(C) + k7(cage)


    CGCS is the coded Glasgow Coma Scale value, CBP is the coded systolic
    blood pressure value, CRR is the coded respiratory rate value, A is the
    anatomic profile component A value, B is the anatomic profile component B
    value, C is the anatomic profile component C value and cage is the coded
    age value.  The k values in the equation are constants, but differ
    depending on whether the patient sustained blunt or penetrating trauma.

    See also the Options and Remarks sections for IMPORTANT information on,
    and requirements for, ascot.


Options

    ASCOT coefficients found in the second ASCOT (A Severity Characterization
    of Trauma) dialog box are the original ASCOT design set model weights.
    If the user has their own database and wishes to calculate their own
    weights, or use weights provided by others, they need only to substitute
    those weights in the second ASCOT (A Severity Characterization of Trauma)
    dialog box.


Remarks

    The user should first run trauma or icdpic on his/her data to add maximum
    severity, anatomic profile component category and blunt\penetrating
    trauma variables.  See help for trauma for descriptions and names of
    these variables.  The user should then run rts or icdpic on his/her data
    to add the coded Glasgow Coma Scale, coded systolic blood pressure, coded
    respiratory rate and revised trauma score (RTS) variables.  See help for 
    rts for descriptions and names of these variables.  Finally, the user's
    data should have an age variable of type integer and a discharge status
    variable of type byte where 0 indicates that the patient survived and 1
    indicates that the patient died.

    ascot adds the following variables to a new copy of the user's data
    stored on disk:


        ps_ascot: ASCOT survival probability
        acage: ASCOT coded age value
        mA: the sum of the squares of the severities of all serious injuries
            with AP component category A
        mB: the sum of the squares of the severities of all serious injuries
            with AP component category B
        mC: the sum of the squares of the severities of all serious injuries
            with AP component category C
        KB: the K term in the equation: Ps = 1/(1 + exp(-K)) for patients
            with blunt trauma
        KP: the K term in the equation: Ps = 1/(1 + exp(-K)) for patients
            with penetrating trauma
        aside: indicates set-aside condition
        sa_alive: number of survivors for the set-aside condition indicated
            by the variable aside
        sa_died: number of non survivors for the set-aside condition
            indicated by the variable aside


    Coded values for Glasgow Coma Scale (GCS), systolic blood pressure (BP)
    and respiratory rate (RR) are found in the table below:


     GCS          BP          RR          Coded Value

    13-15         >89        10-29             4
     9-12        76-89        >29              3
     6-8         50-75        6-9              2
     4-5          1-49        1-5              1
      3            0           0               0


    Coded values for age are found in the table below:


    Coded Age Value          Age (years)

           0                     0-54
           1                    55-64
           2                    65-74
           3                    75-84
           4                     >=85


    Only anatomic profile component categories A, B and C with serious
    injuries (severities between 3 and 5 inclusive) are used to calculate the
    ASCOT survival probability (variable ps_ascot).  Also, ASCOT survival
    probabilities for certain set-aside conditions are calculated separately.
    These set-aside conditions are:


        MAXAIS = 6 & RTS = 0;
        MAXAIS < 6 & RTS = 0;
        MAXAIS = 6 & RTS > 0 and;
        MAXAIS = 1 or 2 & RTS > 0.


    Survival probabilities for these set-aside conditions are determined by
    the number of survivors with a given set-aside condition (variable
    sa_alive) divided by the total number of cases with that set-aside
    condition (variable sa_alive + variable sa_died), separately for both
    blunt and penetrating trauma.

    Values for the aside variable include:


        0--MAXAIS and RTS variable values indicate a non set-aside condition
        1--MAXAIS = 6 and RTS = 0
        2--MAXAIS < 6 and RTS = 0
        3--MAXAIS = 6 and RTS > 0
        4--MAXAIS = 1 or 2 and RTS > 0



    ASCOT survival probability (variable ps_ascot) is only calculated if all
    necessary variables for its calculation contain valid and non missing
    values.

    Variables mA, mB, mC, KB, KP and ps_ascot are rounded to the nearest
    0.0001.

    ASCOT survival probabilities (variable ps_ascot} that are equal, or round
    to, 0.0000 or 1.0000 are replaced with 0.0001 and 0.9999 respectively.


Examples

    None


Authors

    David E. Clark, M.D.

        Maine Medical Center, Portland, Maine, USA
        University of Vermont College of Medicine, Burlington, Vermont, USA
        Harvard Injury Control Research Center, Harvard School of Public
            Health, Boston, Massachusetts, USA

        Correspondence to Dr. Clark,
        887 Congress Street, Portland ME 04102
        Email:  clarkd@mmc.org

    Turner M. Osler, M.D.

        University of Vermont College of Medicine, Burlington, Vermont, USA

    David R. Hahn

        Maine Medical Center, Portland, Maine, USA


References

    Champion HR, Copes WS, Sacco WJ, et al. A new characterization of injury
        severity.  J Trauma 1990;30:539-545.


Also see

    help for trauma

    help for rts

    help for icdpic

    help for ascot