help for elixhaus
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Title

    elixhaus -- Elixhauser Comorbidities


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 Elixhauser Comorbidities program
    directly, type: db elixhaus.  Typing elixhaus, 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 elixhaus

    The Elixhauser Comorbidities dialog box will open.  Follow the
    instructions.

                                      OR

        db icdpic

    The ICDPIC dialog box will open.  Choose Elixhauser Comorbidities and
    click OK or Submit.  The Elixhauser Comorbidities dialog box will open.
    Follow the instructions.


Description

    elixhaus determines which Elixhauser comorbidities are present and the
    number of Elixhauser comorbidities present.

    When determining the number of Elixhauser comorbidities present, only
    complicated hypertension is counted if uncomplicated hypertension is also
    present.  Likewise, only complicated diabetes is counted if uncomplicated
    diabetes is also present.  Finally, only metastatic cancer is counted if
    solid tumor without metastasis is also present.  The above also pertains
    in determining which comorbidities are present.  For example, if both
    complicated and uncomplicated diabetes are present, only the complicated
    diabetes variable will indicate the presence of a comorbidity and is
    counted in determining the number of comorbidities present.

    This program is a STATA interpretation of SAS software (Version 3.3)
    found on the Healthcare Cost and Utilization Project (HCUP) website:


http://www.hcup-us.ahrq.gov/toolssoftware/comorbidity/comorbidity.jsp#download


    It uses data on comorbidity categories, comorbidity diagnosis codes and
    DRG codes found on their website.  This data was valid through September
    30, 2008, at the time this program was written.  This data may differ
    from that found in Elixhauser's original article.  Notably, Elixhauser's
    second comorbidity category of Cardiac Arrhythmias has been dropped.
    Congestive Heart Failure, Complicated Hypertension and Renal Failure
    comorbidity categories no longer have mutually exclusive diagnosis codes.
    Numerous diagnosis codes and DRG codes have been added to comorbidity
    categories, while a few others have been dropped.  elixhaus is only valid
    for use with DRG's prior to Version 25.

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


Options

    ICD-9-CM diagnosis codes in the user's data may, or may not, contain a
    decimal point.  Simply choose the option that applies to your data in the
    Elixhauser Categories dialog box.


Remarks

    The user's data must contain ICD-9-CM diagnosis codes.  Diagnosis codes
    in the user's data must be of type string.  A decimal point in the
    diagnosis codes is optional.  Diagnosis codes should have a width of 5 (6
    if a decimal point is present).  The diagnosis code prefix must be the
    same for all diagnosis codes and numbered sequentially starting with 1,
    for example, dx1...dxN.

    In addition, the user's data must contain an integer variable with
    Diagnosis Related Group (DRG) information prior to Version 25.

    Variables representing Elixhauser's comorbidity categories are numbered
    in order, elix1-elix30.  The user will notice the absence of variable
    elix2, which represents the Cardiac Arrhythmias category which is not
    included in this program.  Variables elix6A and elix6B represent the
    existence of hypertension, uncomplicated and complicated, respectively,
    before combining into the hypertension, combined, category elix6.

    elixhaus adds the following Boolean variables (0 if absent, 1 if present)
    to a new copy of the user's data stored on disk:


        elix1: congestive heart failure
        elix3: vavular disease
        elix4: pulmonary circulation disorders
        elix5: peripheral vascular disorders
        elix6: hypertension combined
        elix6A: hypertension, uncomplicated
        elix6B: hypertension, complicated
        elix7: paralysis
        elix8: other neurological disorders
        elix9: chronic pulmonary disease
        elix10: diabetes, uncomplicated
        elix11: diabetes, complicated
        elix12: hypothyroidism
        elix13: renal failure
        elix14: liver disease
        elix15: peptic ulcer disease, excluding bleeding
        elix16: AIDS
        elix17: lymphoma
        elix18: metastatic cancer
        elix19: solid tumor
        elix20: rheumatoid arthritis/collagen vascular disease
        elix21: coagulopathy
        elix22: obesity
        elix23: weight loss
        elix24: fluid and electrolyte disorders
        elix25: blood loss anemia
        elix26: deficiency anemias
        elix27: alcohol abuse
        elix28: drug abuse
        elix29: psychoses
        elix30: depression


    elixhauser also adds the following variable to a new copy of the user's
    data stored on disk:


        elix_cnt: the total number of comorbidities present


    elixhaus requires the use of lookup tables xtab_s1h.dta, xtab_s2h.dta and
    drgtab_h.dta.  These data tables are supplied.  _s1h tables are for use
    with data without the decimal point in ICD-9-CM codes and _s2h tables\
    are for data that include the decimal point.  See help for icdpic,
    specifically the LOOKUP TABLES part of the Remarks section.


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

    Elixhauser A, Steiner C, Harris DR, Coffey RM. Comorbidity measures for
        use with administrative data. Med Care 1998;36:8-27.


Also see

    help for icdpic

    help for elixhaus