help for srr -------------------------------------------------------------------------------

Title

srr -- Survival Risk Ratio and Independent Survival Risk Ratio Table

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 SRR\SRRi Table program directly, type: db srr. Typing srr, 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 srr

The SRR\SRRi Table dialog box will open. Follow the instructions.

OR

db icdpic

The ICDPIC dialog box will open. Choose SRR\SRRi Table and click OK or Submit. The SRR\SRRi Table dialog box will open. Follow the instructions.

Description

srr calculates the survival risk ratio (SRR) and the independent survival risk ratio (SRRi) for all valid ICD-9-CM injury codes (N-Codes) in a data set and stores them in a file on disk.

SRR and SRRi are defined by analysis of whatever population is deemed the index population.

SRR is equivalent to the number of survivors with a given N-Code divided by the number of survivors plus non survivors with that same N-Code.

SRRi is equivalent to the number of survivors with a given N-Code (and no other N-Codes) divided by the number of survivors plus non survivors with that same N-Code (and no other N-Codes).

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 SRR\SRRi Table 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.

The user's data also requires a Boolean variable of type byte to indicate discharge status. 0 if the patient was discharged alive and 1 if the patient died.

srr adds the following variables to a new file stored on disk:

dx: N-Code survive1: number of observations in the user's data in which a given N-Code occurred and the patient survived expire1: number of observations in the user's data in which a given N-Code occurred and the patient died srr: survival risk ratio (SRR), or survive1/(survive1 + expire1) survive2: number of observations in the user's data in which a given N-Code is the only N-Code and the patient survived expire2: number of observations in the user's data in which a given N-Code is the only N-Code code and the patient died srri: independent survival risk ratio (SRRi), or survive2/(survive2 + expire2)

SRR and SRRi are rounded to the nearest 0.0001. If SRR or SRRi are equal, or round to, 0.0000 or 1.0000 they are replaced with 0.0001 and 0.9999 respectively.

srr requires the use of lookup tables ntab_s1.dta and ntab_s2.dta. These data tables are supplied. _s1 tables are for use with data without the decimal point in ICD-9-CM codes and _s2 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

None

Also see

help for iciss

help for icdpic

help for srr